- sort
排序，依照行或自定义字段
SYNOPSIS
sort [OPTION]... [FILE]...
sort [OPTION]... --files0-from=F
DESCRIPTION
Write sorted concatenation of all FILE(s) to standard output.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too. Ordering options:
-b, --ignore-leading-blanks
ignore leading blanks
-d, --dictionary-order
consider only blanks and alphanumeric characters
-f, --ignore-case
fold lower case to upper case characters
-g, --general-numeric-sort
compare according to general numerical value
-i, --ignore-nonprinting
consider only printable characters
-M, --month-sort
compare (unknown) < 'JAN' < ... < 'DEC'
-h, --human-numeric-sort
compare human readable numbers (e.g., 2K 1G)
-n, --numeric-sort
compare according to string numerical value
-R, --random-sort
shuffle, but group identical keys. See shuf(1)
--random-source=FILE
get random bytes from FILE
-r, --reverse
reverse the result of comparisons
--sort=WORD
sort according to WORD: general-numeric -g, human-numeric -h, month -M, numeric -n, random -R, version -V
-V, --version-sort
natural sort of (version) numbers within text
Other options:
--batch-size=NMERGE
merge at most NMERGE inputs at once; for more use temp files
-c, --check, --check=diagnose-first
check for sorted input; do not sort
-C, --check=quiet, --check=silent
like -c, but do not report first bad line
--compress-program=PROG
compress temporaries with PROG; decompress them with PROG -d
--debug
annotate the part of the line used to sort, and warn about questionable usage to stderr
--files0-from=F
read input from the files specified by NUL-terminated names in file F; If F is - then read names from standard input
-k, --key=KEYDEF
sort via a key; KEYDEF gives location and type
-m, --merge
merge already sorted files; do not sort
-o, --output=FILE
write result to FILE instead of standard output
-s, --stable
stabilize sort by disabling last-resort comparison
-S, --buffer-size=SIZE
use SIZE for main memory buffer
-t, --field-separator=SEP
use SEP instead of non-blank to blank transition
-T, --temporary-directory=DIR
use DIR for temporaries, not $TMPDIR or /tmp; multiple options specify multiple directories
--parallel=N
change the number of sorts run concurrently to N
-u, --unique
with -c, check for strict ordering; without -c, output only the first of an equal run
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
KEYDEF is F[.C][OPTS][,F[.C][OPTS]] for start and stop position, where F is a field number and C a character position in the field; both are origin 1, and the stop position de‐
faults to the line's end. If neither -t nor -b is in effect, characters in a field are counted from the beginning of the preceding whitespace. OPTS is one or more single-letter
ordering options [bdfgiMhnRrV], which override global ordering options for that key. If no key is given, use the entire line as the key. Use --debug to diagnose incorrect key
usage.
SIZE may be followed by the following multiplicative suffixes: % 1% of memory, b 1, K 1024 (default), and so on for M, G, T, P, E, Z, Y.
*** WARNING *** The locale specified by the environment affects sort order. Set LC_ALL=C to get the traditional sort order that uses native byte values.
AUTHOR
Written by Mike Haertel and Paul Eggert.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
shuf(1), uniq(1)
Full documentation <https://www.gnu.org/software/coreutils/sort>
or available locally via: info '(coreutils) sort invocation'
GNU coreutils 8.31 March 2019 SORT(1)
- uniq
去重
SYNOPSIS
uniq [OPTION]... [INPUT [OUTPUT]]
DESCRIPTION
Filter adjacent matching lines from INPUT (or standard input), writing
to OUTPUT (or standard output).
With no options, matching lines are merged to the first occurrence.
Mandatory arguments to long options are mandatory for short options
too.
-c, --count
prefix lines by the number of occurrences
-d, --repeated
only print duplicate lines, one for each group
-D print all duplicate lines
--all-repeated[=METHOD]
like -D, but allow separating groups with an empty line;
METHOD={none(default),prepend,separate}
-f, --skip-fields=N
avoid comparing the first N fields
--group[=METHOD]
show all items, separating groups with an empty line;
METHOD={separate(default),prepend,append,both}
-i, --ignore-case
ignore differences in case when comparing
-s, --skip-chars=N
avoid comparing the first N characters
-u, --unique
only print unique lines
-z, --zero-terminated
line delimiter is NUL, not newline
-w, --check-chars=N
compare no more than N characters in lines
--help display this help and exit
--version
output version information and exit
A field is a run of blanks (usually spaces and/or TABs), then
non-blank characters. Fields are skipped before chars.
Note: 'uniq' does not detect repeated lines unless they are adjacent.
You may want to sort the input first, or use 'sort -u' without 'uniq'.
Also, comparisons honor the rules specified by 'LC_COLLATE'.
AUTHOR
Written by Richard M. Stallman and David MacKenzie.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
comm(1), join(1), sort(1)
Full documentation <https://www.gnu.org/software/coreutils/uniq>
or available locally via: info '(coreutils) uniq invocation'
GNU coreutils 8.31 March 2019 UNIQ(1)
- wc
统计文本行数，字数以及字符数
SYNOPSIS
wc [OPTION]... [FILE]...
wc [OPTION]... --files0-from=F
DESCRIPTION
Print newline, word, and byte counts for each FILE, and a total line
if more than one FILE is specified. A word is a non-zero-length se‐
quence of characters delimited by white space.
With no FILE, or when FILE is -, read standard input.
The options below may be used to select which counts are printed, al‐
ways in the following order: newline, word, character, byte, maximum
line length.
-c, --bytes
print the byte counts
-m, --chars
print the character counts
-l, --lines
print the newline counts
--files0-from=F
read input from the files specified by NUL-terminated names in
file F; If F is - then read names from standard input
-L, --max-line-length
print the maximum display width
-w, --words
print the word counts
--help display this help and exit
--version
output version information and exit
AUTHOR
Written by Paul Rubin and David MacKenzie.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/wc>
or available locally via: info '(coreutils) wc invocation'
GNU coreutils 8.31 March 2019 WC(1)
- pr
打印文件
SYNOPSIS
pr [OPTION]... [FILE]...
DESCRIPTION
Paginate or columnate FILE(s) for printing.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
+FIRST_PAGE[:LAST_PAGE], --pages=FIRST_PAGE[:LAST_PAGE]
begin [stop] printing with page FIRST_[LAST_]PAGE
-COLUMN, --columns=COLUMN
output COLUMN columns and print columns down, unless -a is
used. Balance number of lines in the columns on each page
-a, --across
print columns across rather than down, used together with -COL‐
UMN
-c, --show-control-chars
use hat notation (^G) and octal backslash notation
-d, --double-space
double space the output
-D, --date-format=FORMAT
use FORMAT for the header date
-e[CHAR[WIDTH]], --expand-tabs[=CHAR[WIDTH]]
expand input CHARs (TABs) to tab WIDTH (8)
-F, -f, --form-feed
use form feeds instead of newlines to separate pages (by a
3-line page header with -F or a 5-line header and trailer with‐
out -F)
-h, --header=HEADER
use a centered HEADER instead of filename in page header, -h ""
prints a blank line, don't use -h""
-i[CHAR[WIDTH]], --output-tabs[=CHAR[WIDTH]]
replace spaces with CHARs (TABs) to tab WIDTH (8)
-J, --join-lines
merge full lines, turns off -W line truncation, no column
alignment, --sep-string[=STRING] sets separators
-l, --length=PAGE_LENGTH
set the page length to PAGE_LENGTH (66) lines (default number
of lines of text 56, and with -F 63). implies -t if
PAGE_LENGTH <= 10
-m, --merge
print all files in parallel, one in each column, truncate
lines, but join lines of full length with -J
-n[SEP[DIGITS]], --number-lines[=SEP[DIGITS]]
number lines, use DIGITS (5) digits, then SEP (TAB), default
counting starts with 1st line of input file
-N, --first-line-number=NUMBER
start counting with NUMBER at 1st line of first page printed
(see +FIRST_PAGE)
-o, --indent=MARGIN
offset each line with MARGIN (zero) spaces, do not affect -w or
-W, MARGIN will be added to PAGE_WIDTH
-r, --no-file-warnings
omit warning when a file cannot be opened
-s[CHAR], --separator[=CHAR]
separate columns by a single character, default for CHAR is the
<TAB> character without -w and 'no char' with -w. -s[CHAR]
turns off line truncation of all 3 column options (-COLUMN|-a
-COLUMN|-m) except -w is set
-S[STRING], --sep-string[=STRING]
separate columns by STRING, without -S: Default separator <TAB>
with -J and <space> otherwise (same as -S" "), no effect on
column options
-t, --omit-header
omit page headers and trailers; implied if PAGE_LENGTH <= 10
-T, --omit-pagination
omit page headers and trailers, eliminate any pagination by
form feeds set in input files
-v, --show-nonprinting
use octal backslash notation
-w, --width=PAGE_WIDTH
set page width to PAGE_WIDTH (72) characters for multiple
text-column output only, -s[char] turns off (72)
-W, --page-width=PAGE_WIDTH
set page width to PAGE_WIDTH (72) characters always, truncate
lines, except -J option is set, no interference with -S or -s
--help display this help and exit
--version
output version information and exit
AUTHOR
Written by Pete TerMaat and Roland Huebner.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/pr>
or available locally via: info '(coreutils) pr invocation'
GNU coreutils 8.31 March 2019 PR(1)
- fmt
格式化文本
SYNOPSIS
fmt [-WIDTH] [OPTION]... [FILE]...
DESCRIPTION
Reformat each paragraph in the FILE(s), writing to standard output.
The option -WIDTH is an abbreviated form of --width=DIGITS.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-c, --crown-margin
preserve indentation of first two lines
-p, --prefix=STRING
reformat only lines beginning with STRING, reattaching the pre‐
fix to reformatted lines
-s, --split-only
split long lines, but do not refill
-t, --tagged-paragraph
indentation of first line different from second
-u, --uniform-spacing
one space between words, two after sentences
-w, --width=WIDTH
maximum line width (default of 75 columns)
-g, --goal=WIDTH
goal width (default of 93% of width)
--help display this help and exit
--version
output version information and exit
AUTHOR
Written by Ross Paterson.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/fmt>
or available locally via: info '(coreutils) fmt invocation'
GNU coreutils 8.31 March 2019 FMT(1)
- fold
限制文本宽度
SYNOPSIS
fold [OPTION]... [FILE]...
DESCRIPTION
Wrap input lines in each FILE, writing to standard output.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-b, --bytes
count bytes rather than columns
-s, --spaces
break at spaces
-w, --width=WIDTH
use WIDTH columns instead of 80
--help display this help and exit
--version
output version information and exit
AUTHOR
Written by David MacKenzie.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/fold>
or available locally via: info '(coreutils) fold invocation'
GNU coreutils 8.31 March 2019 FOLD(1)
- head，tail
提取文本开头和结尾
SYNOPSIS
head [OPTION]... [FILE]...
DESCRIPTION
Print the first 10 lines of each FILE to standard output. With more
than one FILE, precede each with a header giving the file name.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-c, --bytes=[-]NUM
print the first NUM bytes of each file; with the leading '-',
print all but the last NUM bytes of each file
-n, --lines=[-]NUM
print the first NUM lines instead of the first 10; with the
leading '-', print all but the last NUM lines of each file
-q, --quiet, --silent
never print headers giving file names
-v, --verbose
always print headers giving file names
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
NUM may have a multiplier suffix: b 512, kB 1000, K 1024, MB
1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on
for T, P, E, Z, Y. Binary prefixes can be used, too: KiB=K, MiB=M,
and so on.
AUTHOR
Written by David MacKenzie and Jim Meyering.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
tail(1)
Full documentation <https://www.gnu.org/software/coreutils/head>
or available locally via: info '(coreutils) head invocation'
GNU coreutils 8.31 March 2019 HEAD(1)
SYNOPSIS
tail [OPTION]... [FILE]...
DESCRIPTION
Print the last 10 lines of each FILE to standard output. With more
than one FILE, precede each with a header giving the file name.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-c, --bytes=[+]NUM
output the last NUM bytes; or use -c +NUM to output starting
with byte NUM of each file
-f, --follow[={name|descriptor}]
output appended data as the file grows;
an absent option argument means 'descriptor'
-F same as --follow=name --retry
-n, --lines=[+]NUM
output the last NUM lines, instead of the last 10; or use -n
+NUM to output starting with line NUM
--max-unchanged-stats=N
with --follow=name, reopen a FILE which has not
changed size after N (default 5) iterations to see if it has
been unlinked or renamed (this is the usual case of rotated log
files); with inotify, this option is rarely useful
--pid=PID
with -f, terminate after process ID, PID dies
-q, --quiet, --silent
never output headers giving file names
--retry
keep trying to open a file if it is inaccessible
-s, --sleep-interval=N
with -f, sleep for approximately N seconds (default 1.0) be‐
tween iterations; with inotify and --pid=P, check process P at
least once every N seconds
-v, --verbose
always output headers giving file names
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
NUM may have a multiplier suffix: b 512, kB 1000, K 1024, MB
1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on
for T, P, E, Z, Y. Binary prefixes can be used, too: KiB=K, MiB=M,
and so on.
With --follow (-f), tail defaults to following the file descriptor,
which means that even if a tail'ed file is renamed, tail will continue
to track its end. This default behavior is not desirable when you re‐
ally want to track the actual name of the file, not the file descrip‐
tor (e.g., log rotation). Use --follow=name in that case. That
causes tail to track the named file in a way that accommodates renam‐
ing, removal and creation.
AUTHOR
Written by Paul Rubin, David MacKenzie, Ian Lance Taylor, and Jim Mey‐
ering.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
head(1)
Full documentation <https://www.gnu.org/software/coreutils/tail>
or available locally via: info '(coreutils) tail invocation'
GNU coreutils 8.31 March 2019 TAIL(1)
- cut
取出字段，参数：
-d 字段分隔符
-f 获取字段列
SYNOPSIS
cut OPTION... [FILE]...
DESCRIPTION
Print selected parts of lines from each FILE to standard output.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-b, --bytes=LIST
select only these bytes
-c, --characters=LIST
select only these characters
-d, --delimiter=DELIM
use DELIM instead of TAB for field delimiter
-f, --fields=LIST
select only these fields; also print any line that contains no
delimiter character, unless the -s option is specified
-n (ignored)
--complement
complement the set of selected bytes, characters or fields
-s, --only-delimited
do not print lines not containing delimiters
--output-delimiter=STRING
use STRING as the output delimiter the default is to use the
input delimiter
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
Use one, and only one of -b, -c or -f. Each LIST is made up of one
range, or many ranges separated by commas. Selected input is written
in the same order that it is read, and is written exactly once. Each
range is one of:
N N'th byte, character or field, counted from 1
N- from N'th byte, character or field, to end of line
N-M from N'th to M'th (included) byte, character or field
-M from first to M'th (included) byte, character or field
AUTHOR
Written by David M. Ihnat, David MacKenzie, and Jim Meyering.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/cut>
or available locally via: info '(coreutils) cut invocation'
GNU coreutils 8.31 March 2019 CUT(1)
- join
连接字段 -a1 -a2
SYNOPSIS
join [OPTION]... FILE1 FILE2
DESCRIPTION
For each pair of input lines with identical join fields, write a line
to standard output. The default join field is the first, delimited by
blanks.
When FILE1 or FILE2 (not both) is -, read standard input.
-a FILENUM
also print unpairable lines from file FILENUM, where FILENUM is
1 or 2, corresponding to FILE1 or FILE2
-e EMPTY
replace missing input fields with EMPTY
-i, --ignore-case
ignore differences in case when comparing fields
-j FIELD
equivalent to '-1 FIELD -2 FIELD'
-o FORMAT
obey FORMAT while constructing output line
-t CHAR
use CHAR as input and output field separator
-v FILENUM
like -a FILENUM, but suppress joined output lines
-1 FIELD
join on this FIELD of file 1
-2 FIELD
join on this FIELD of file 2
--check-order
check that the input is correctly sorted, even if all input
lines are pairable
--nocheck-order
do not check that the input is correctly sorted
--header
treat the first line in each file as field headers, print them
without trying to pair them
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
Unless -t CHAR is given, leading blanks separate fields and are ig‐
nored, else fields are separated by CHAR. Any FIELD is a field number
counted from 1. FORMAT is one or more comma or blank separated speci‐
fications, each being 'FILENUM.FIELD' or '0'. Default FORMAT outputs
the join field, the remaining fields from FILE1, the remaining fields
from FILE2, all separated by CHAR. If FORMAT is the keyword 'auto',
then the first line of each file determines the number of fields out‐
put for each line.
Important: FILE1 and FILE2 must be sorted on the join fields. E.g.,
use "sort -k 1b,1" if 'join' has no options, or use "join -t ''" if
'sort' has no options. Note, comparisons honor the rules specified by
'LC_COLLATE'. If the input is not sorted and some lines cannot be
joined, a warning message will be given.
AUTHOR
Written by Mike Haertel.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
comm(1), uniq(1)
Full documentation <https://www.gnu.org/software/coreutils/join>
or available locally via: info '(coreutils) join invocation'
GNU coreutils 8.31 March 2019 JOIN(1)
- tr
替换字符 tr ‘a-z’ ‘A-Z’ <1.txt >2.txt
创建单词列表：
tr -cs ‘[:lower:][:upper:]’ ‘[\n*]’ <1.txt >2.txt
SYNOPSIS
tr [OPTION]... SET1 [SET2]
DESCRIPTION
Translate, squeeze, and/or delete characters from standard input,
writing to standard output.
-c, -C, --complement
use the complement of SET1
-d, --delete
delete characters in SET1, do not translate
-s, --squeeze-repeats
replace each sequence of a repeated character that is listed in
the last specified SET, with a single occurrence of that char‐
acter
-t, --truncate-set1
first truncate SET1 to length of SET2
--help display this help and exit
--version
output version information and exit
SETs are specified as strings of characters. Most represent them‐
selves. Interpreted sequences are:
\NNN character with octal value NNN (1 to 3 octal digits)
\\ backslash
\a audible BEL
\b backspace
\f form feed
\n new line
\r return
\t horizontal tab
\v vertical tab
CHAR1-CHAR2
all characters from CHAR1 to CHAR2 in ascending order
[CHAR*]
in SET2, copies of CHAR until length of SET1
[CHAR*REPEAT]
REPEAT copies of CHAR, REPEAT octal if starting with 0
[:alnum:]
all letters and digits
[:alpha:]
all letters
[:blank:]
all horizontal whitespace
[:cntrl:]
all control characters
[:digit:]
all digits
[:graph:]
all printable characters, not including space
[:lower:]
all lower case letters
[:print:]
all printable characters, including space
[:punct:]
all punctuation characters
[:space:]
all horizontal or vertical whitespace
[:upper:]
all upper case letters
[:xdigit:]
all hexadecimal digits
[=CHAR=]
all characters which are equivalent to CHAR
Translation occurs if -d is not given and both SET1 and SET2 appear.
-t may be used only when translating. SET2 is extended to length of
SET1 by repeating its last character as necessary. Excess characters
of SET2 are ignored. Only [:lower:] and [:upper:] are guaranteed to
expand in ascending order; used in SET2 while translating, they may
only be used in pairs to specify case conversion. -s uses the last
specified SET, and occurs after translation or deletion.
AUTHOR
Written by Jim Meyering.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/tr>
or available locally via: info '(coreutils) tr invocation'
GNU coreutils 8.31 March 2019 TR(1)
- sed
流编辑
sed -e “d” 1.txt 删除第一行
sed -e “5d” 1.txt 删除第五行
sed -e ‘1,5d’ 1.txt 删除一到五行
sed -n -e ‘regexp/p’ file | more 删除任意匹配的行
替换
sed -e ‘s/power/jiechen/g’ 1.txt
替换命令格式 ‘s///’ g表示全部
sed -e ‘1,10s’/power/jiechen/g’ 1.txt s之后的符号直接被指定为分隔符，范围，前10行
sed -e ‘s:/usr/local:/usr:g’ 1.txt
sed -e ‘s/<[^>’]*>//g’1.html 删除<.*>
还有更多未列出
SYNOPSIS
sed [OPTION]... {script-only-if-no-other-script} [input-file]...
DESCRIPTION
Sed is a stream editor. A stream editor is used to perform basic text
transformations on an input stream (a file or input from a pipeline).
While in some ways similar to an editor which permits scripted edits
(such as ed), sed works by making only one pass over the input(s), and
is consequently more efficient. But it is sed's ability to filter
text in a pipeline which particularly distinguishes it from other
types of editors.
-n, --quiet, --silent
suppress automatic printing of pattern space
--debug
annotate program execution
-e script, --expression=script
add the script to the commands to be executed
-f script-file, --file=script-file
add the contents of script-file to the commands to be executed
--follow-symlinks
follow symlinks when processing in place
-i[SUFFIX], --in-place[=SUFFIX]
edit files in place (makes backup if SUFFIX supplied)
-l N, --line-length=N
specify the desired line-wrap length for the `l' command
--posix
disable all GNU extensions.
-E, -r, --regexp-extended
use extended regular expressions in the script (for portability
use POSIX -E).
-s, --separate
consider files as separate rather than as a single, continuous
long stream.
--sandbox
operate in sandbox mode (disable e/r/w commands).
-u, --unbuffered
load minimal amounts of data from the input files and flush the
output buffers more often
-z, --null-data
separate lines by NUL characters
--help
display this help and exit
--version
output version information and exit
If no -e, --expression, -f, or --file option is given, then the first
non-option argument is taken as the sed script to interpret. All re‐
maining arguments are names of input files; if no input files are
specified, then the standard input is read.
GNU sed home page: <https://www.gnu.org/software/sed/>. General help
using GNU software: <https://www.gnu.org/gethelp/>. E-mail bug re‐
ports to: <bug-sed@gnu.org>.
COMMAND SYNOPSIS
This is just a brief synopsis of sed commands to serve as a reminder
to those who already know sed; other documentation (such as the tex‐
info document) must be consulted for fuller descriptions.
Zero-address ``commands''
: label
Label for b and t commands.
#comment
The comment extends until the next newline (or the end of a -e
script fragment).
} The closing bracket of a { } block.
Zero- or One- address commands
= Print the current line number.
a \
text Append text, which has each embedded newline preceded by a
backslash.
i \
text Insert text, which has each embedded newline preceded by a
backslash.
q [exit-code]
Immediately quit the sed script without processing any more in‐
put, except that if auto-print is not disabled the current pat‐
tern space will be printed. The exit code argument is a GNU
extension.
Q [exit-code]
Immediately quit the sed script without processing any more in‐
put. This is a GNU extension.
r filename
Append text read from filename.
R filename
Append a line read from filename. Each invocation of the com‐
mand reads a line from the file. This is a GNU extension.
Commands which accept address ranges
{ Begin a block of commands (end with a }).
b label
Branch to label; if label is omitted, branch to end of script.
c \
text Replace the selected lines with text, which has each embedded
newline preceded by a backslash.
d Delete pattern space. Start next cycle.
D If pattern space contains no newline, start a normal new cycle
as if the d command was issued. Otherwise, delete text in the
pattern space up to the first newline, and restart cycle with
the resultant pattern space, without reading a new line of in‐
put.
h H Copy/append pattern space to hold space.
g G Copy/append hold space to pattern space.
l List out the current line in a ``visually unambiguous'' form.
l width
List out the current line in a ``visually unambiguous'' form,
breaking it at width characters. This is a GNU extension.
n N Read/append the next line of input into the pattern space.
p Print the current pattern space.
P Print up to the first embedded newline of the current pattern
space.
s/regexp/replacement/
Attempt to match regexp against the pattern space. If success‐
ful, replace that portion matched with replacement. The re‐
placement may contain the special character & to refer to that
portion of the pattern space which matched, and the special es‐
capes \1 through \9 to refer to the corresponding matching sub-
expressions in the regexp.
t label
If a s/// has done a successful substitution since the last in‐
put line was read and since the last t or T command, then
branch to label; if label is omitted, branch to end of script.
T label
If no s/// has done a successful substitution since the last
input line was read and since the last t or T command, then
branch to label; if label is omitted, branch to end of script.
This is a GNU extension.
w filename
Write the current pattern space to filename.
W filename
Write the first line of the current pattern space to filename.
This is a GNU extension.
x Exchange the contents of the hold and pattern spaces.
y/source/dest/
Transliterate the characters in the pattern space which appear
in source to the corresponding character in dest.
Addresses
Sed commands can be given with no addresses, in which case the command
will be executed for all input lines; with one address, in which case
the command will only be executed for input lines which match that ad‐
dress; or with two addresses, in which case the command will be exe‐
cuted for all input lines which match the inclusive range of lines
starting from the first address and continuing to the second address.
Three things to note about address ranges: the syntax is addr1,addr2
(i.e., the addresses are separated by a comma); the line which addr1
matched will always be accepted, even if addr2 selects an earlier
line; and if addr2 is a regexp, it will not be tested against the line
that addr1 matched.
After the address (or address-range), and before the command, a ! may
be inserted, which specifies that the command shall only be executed
if the address (or address-range) does not match.
The following address types are supported:
number Match only the specified line number (which increments cumula‐
tively across files, unless the -s option is specified on the
command line).
first~step
Match every step'th line starting with line first. For exam‐
ple, ``sed -n 1~2p'' will print all the odd-numbered lines in
the input stream, and the address 2~5 will match every fifth
line, starting with the second. first can be zero; in this
case, sed operates as if it were equal to step. (This is an
extension.)
$ Match the last line.
/regexp/
Match lines matching the regular expression regexp. Matching
is performed on the current pattern space, which can be modi‐
fied with commands such as ``s///''.
\cregexpc
Match lines matching the regular expression regexp. The c may
be any character.
GNU sed also supports some special 2-address forms:
0,addr2
Start out in "matched first address" state, until addr2 is
found. This is similar to 1,addr2, except that if addr2
matches the very first line of input the 0,addr2 form will be
at the end of its range, whereas the 1,addr2 form will still be
at the beginning of its range. This works only when addr2 is a
regular expression.
addr1,+N
Will match addr1 and the N lines following addr1.
addr1,~N
Will match addr1 and the lines following addr1 until the next
line whose input line number is a multiple of N.
REGULAR EXPRESSIONS
POSIX.2 BREs should be supported, but they aren't completely because
of performance problems. The \n sequence in a regular expression
matches the newline character, and similarly for \a, \t, and other se‐
quences. The -E option switches to using extended regular expressions
instead; it has been supported for years by GNU sed, and is now in‐
cluded in POSIX.
BUGS
E-mail bug reports to bug-sed@gnu.org. Also, please include the out‐
put of ``sed --version'' in the body of your report if at all possi‐
ble.
AUTHOR
Written by Jay Fenlason, Tom Lord, Ken Pizzini, Paolo Bonzini, Jim
Meyering, and Assaf Gordon. GNU sed home page:
<https://www.gnu.org/software/sed/>. General help using GNU software:
<https://www.gnu.org/gethelp/>. E-mail bug reports to: <bug-
sed@gnu.org>.
COPYRIGHT
Copyright © 2018 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
awk(1), ed(1), grep(1), tr(1), perlre(1), sed.info, any of various
books on sed, the sed FAQ (http://sed.sf.net/grabbag/tutorials/sed‐
faq.txt), http://sed.sf.net/grabbag/.
The full documentation for sed is maintained as a Texinfo manual. If
the info and sed programs are properly installed at your site, the
command
info sed
should give you access to the complete manual.
sed 4.7 December 2018 SED(1)
- awk
常用内建变量
FILENAME 当前输入文件名称
FNR 当前输入文件记录数
FS 字段分隔符，默认为空格
NF 当前记录的字段数
NR 在工作（job）中的记录数
OFS 输出字段分割字符
ORS 输出记录分割字符（默认为\n）
RS 输入记录分割字符
awk运算符
判断与循环
if语句
if/else语句
if/else else/if 语句
while循环
do/while循环
for循环
break语句
contunue
SYNOPSIS
gawk [ POSIX or GNU style options ] -f program-file [ -- ] file ...
gawk [ POSIX or GNU style options ] [ -- ] program-text file ...
DESCRIPTION
Gawk is the GNU Project's implementation of the AWK programming lan‐
guage. It conforms to the definition of the language in the POSIX
1003.1 Standard. This version in turn is based on the description in
The AWK Programming Language, by Aho, Kernighan, and Weinberger. Gawk
provides the additional features found in the current version of Brian
Kernighan's awk and a number of GNU-specific extensions.
The command line consists of options to gawk itself, the AWK program
text (if not supplied via the -f or --file options), and values to be
made available in the ARGC and ARGV pre-defined AWK variables.
When gawk is invoked with the --profile option, it starts gathering
profiling statistics from the execution of the program. Gawk runs
more slowly in this mode, and automatically produces an execution pro‐
file in the file awkprof.out when done. See the --profile option,
below.
Gawk also has an integrated debugger. An interactive debugging session
can be started by supplying the --debug option to the command line. In
this mode of execution, gawk loads the AWK source code and then
prompts for debugging commands. Gawk can only debug AWK program
source provided with the -f option. The debugger is documented in
GAWK: Effective AWK Programming.
OPTION FORMAT
Gawk options may be either traditional POSIX-style one letter options,
or GNU-style long options. POSIX options start with a single “-”,
while long options start with “--”. Long options are provided for
both GNU-specific features and for POSIX-mandated features.
Gawk-specific options are typically used in long-option form. Argu‐
ments to long options are either joined with the option by an = sign,
with no intervening spaces, or they may be provided in the next com‐
mand line argument. Long options may be abbreviated, as long as the
abbreviation remains unique.
Additionally, every long option has a corresponding short option, so
that the option's functionality may be used from within #! executable
scripts.
OPTIONS
Gawk accepts the following options. Standard options are listed
first, followed by options for gawk extensions, listed alphabetically
by short option.
-f program-file
--file program-file
Read the AWK program source from the file program-file, instead
of from the first command line argument. Multiple -f (or
--file) options may be used.
-F fs
--field-separator fs
Use fs for the input field separator (the value of the FS pre‐
defined variable).
-v var=val
--assign var=val
Assign the value val to the variable var, before execution of
the program begins. Such variable values are available to the
BEGIN rule of an AWK program.
-b
--characters-as-bytes
Treat all input data as single-byte characters. In other words,
don't pay any attention to the locale information when attempt‐
ing to process strings as multibyte characters. The --posix
option overrides this one.
-c
--traditional
Run in compatibility mode. In compatibility mode, gawk behaves
identically to Brian Kernighan's awk; none of the GNU-specific
extensions are recognized. See GNU EXTENSIONS, below, for more
information.
-C
--copyright
Print the short version of the GNU copyright information mes‐
sage on the standard output and exit successfully.
-d[file]
--dump-variables[=file]
Print a sorted list of global variables, their types and final
values to file. If no file is provided, gawk uses a file named
awkvars.out in the current directory.
Having a list of all the global variables is a good way to look
for typographical errors in your programs. You would also use
this option if you have a large program with a lot of func‐
tions, and you want to be sure that your functions don't inad‐
vertently use global variables that you meant to be local.
(This is a particularly easy mistake to make with simple vari‐
able names like i, j, and so on.)
-D[file]
--debug[=file]
Enable debugging of AWK programs. By default, the debugger
reads commands interactively from the keyboard (standard
input). The optional file argument specifies a file with a
list of commands for the debugger to execute non-interactively.
-e program-text
--source program-text
Use program-text as AWK program source code. This option
allows the easy intermixing of library functions (used via the
-f and --file options) with source code entered on the command
line. It is intended primarily for medium to large AWK pro‐
grams used in shell scripts.
-E file
--exec file
Similar to -f, however, this is option is the last one pro‐
cessed. This should be used with #! scripts, particularly for
CGI applications, to avoid passing in options or source code
(!) on the command line from a URL. This option disables com‐
mand-line variable assignments.
-g
--gen-pot
Scan and parse the AWK program, and generate a GNU .pot (Porta‐
ble Object Template) format file on standard output with
entries for all localizable strings in the program. The pro‐
gram itself is not executed. See the GNU gettext distribution
for more information on .pot files.
-h
--help Print a relatively short summary of the available options on
the standard output. (Per the GNU Coding Standards, these
options cause an immediate, successful exit.)
-i include-file
--include include-file
Load an awk source library. This searches for the library
using the AWKPATH environment variable. If the initial search
fails, another attempt will be made after appending the .awk
suffix. The file will be loaded only once (i.e., duplicates
are eliminated), and the code does not constitute the main pro‐
gram source.
-l lib
--load lib
Load a shared library lib. This searches for the library using
the AWKLIBPATH environment variable. If the initial search
fails, another attempt will be made after appending the default
shared library suffix for the platform. The library initial‐
ization routine is expected to be named dl_load().
-L [value]
--lint[=value]
Provide warnings about constructs that are dubious or non-por‐
table to other AWK implementations. With an optional argument
of fatal, lint warnings become fatal errors. This may be dras‐
tic, but its use will certainly encourage the development of
cleaner AWK programs. With an optional argument of invalid,
only warnings about things that are actually invalid are
issued. (This is not fully implemented yet.)
-M
--bignum
Force arbitrary precision arithmetic on numbers. This option
has no effect if gawk is not compiled to use the GNU MPFR and
MP libraries.
-n
--non-decimal-data
Recognize octal and hexadecimal values in input data. Use this
option with great caution!
-N
--use-lc-numeric
This forces gawk to use the locale's decimal point character
when parsing input data. Although the POSIX standard requires
this behavior, and gawk does so when --posix is in effect, the
default is to follow traditional behavior and use a period as
the decimal point, even in locales where the period is not the
decimal point character. This option overrides the default
behavior, without the full draconian strictness of the --posix
option.
-o[file]
--pretty-print[=file]
Output a pretty printed version of the program to file. If no
file is provided, gawk uses a file named awkprof.out in the
current directory.
-O
--optimize
Enable optimizations upon the internal representation of the
program. Currently, this includes simple constant-folding, and
tail call elimination for recursive functions. The gawk main‐
tainer hopes to add additional optimizations over time.
-p[prof-file]
--profile[=prof-file]
Start a profiling session, and send the profiling data to prof-
file. The default is awkprof.out. The profile contains execu‐
tion counts of each statement in the program in the left margin
and function call counts for each user-defined function.
-P
--posix
This turns on compatibility mode, with the following additional
restrictions:
· \x escape sequences are not recognized.
· Only space and tab act as field separators when FS is set to
a single space, newline does not.
· You cannot continue lines after ? and :.
· The synonym func for the keyword function is not recognized.
· The operators ** and **= cannot be used in place of ^ and ^=.
-r
--re-interval
Enable the use of interval expressions in regular expression
matching (see Regular Expressions, below). Interval expres‐
sions were not traditionally available in the AWK language.
The POSIX standard added them, to make awk and egrep consistent
with each other. They are enabled by default, but this option
remains for use with --traditional.
-S
--sandbox
Runs gawk in sandbox mode, disabling the system() function,
input redirection with getline, output redirection with print
and printf, and loading dynamic extensions. Command execution
(through pipelines) is also disabled. This effectively blocks
a script from accessing local resources (except for the files
specified on the command line).
-t
--lint-old
Provide warnings about constructs that are not portable to the
original version of UNIX awk.
-V
--version
Print version information for this particular copy of gawk on
the standard output. This is useful mainly for knowing if the
current copy of gawk on your system is up to date with respect
to whatever the Free Software Foundation is distributing. This
is also useful when reporting bugs. (Per the GNU Coding Stan‐
dards, these options cause an immediate, successful exit.)
-- Signal the end of options. This is useful to allow further
arguments to the AWK program itself to start with a “-”. This
provides consistency with the argument parsing convention used
by most other POSIX programs.
In compatibility mode, any other options are flagged as invalid, but
are otherwise ignored. In normal operation, as long as program text
has been supplied, unknown options are passed on to the AWK program in
the ARGV array for processing. This is particularly useful for run‐
ning AWK programs via the “#!” executable interpreter mechanism.
For POSIX compatibility, the -W option may be used, followed by the
name of a long option.
AWK PROGRAM EXECUTION
An AWK program consists of a sequence of pattern-action statements and
optional function definitions.
@include "filename"
@load "filename"
pattern { action statements }
function name(parameter list) { statements }
Gawk first reads the program source from the program-file(s) if speci‐
fied, from arguments to --source, or from the first non-option argu‐
ment on the command line. The -f and --source options may be used
multiple times on the command line. Gawk reads the program text as if
all the program-files and command line source texts had been concate‐
nated together. This is useful for building libraries of AWK func‐
tions, without having to include them in each new AWK program that
uses them. It also provides the ability to mix library functions with
command line programs.
In addition, lines beginning with @include may be used to include
other source files into your program, making library use even easier.
This is equivalent to using the -i option.
Lines beginning with @load may be used to load shared libraries into
your program. This is equivalent to using the -l option.
The environment variable AWKPATH specifies a search path to use when
finding source files named with the -f and -i options. If this vari‐
able does not exist, the default path is ".:/usr/local/share/awk".
(The actual directory may vary, depending upon how gawk was built and
installed.) If a file name given to the -f option contains a “/”
character, no path search is performed.
The environment variable AWKLIBPATH specifies a search path to use
when finding source files named with the -l option. If this variable
does not exist, the default path is "/usr/local/lib/gawk". (The
actual directory may vary, depending upon how gawk was built and
installed.)
Gawk executes AWK programs in the following order. First, all vari‐
able assignments specified via the -v option are performed. Next,
gawk compiles the program into an internal form. Then, gawk executes
the code in the BEGIN rule(s) (if any), and then proceeds to read each
file named in the ARGV array (up to ARGV[ARGC]). If there are no
files named on the command line, gawk reads the standard input.
If a filename on the command line has the form var=val it is treated
as a variable assignment. The variable var will be assigned the value
val. (This happens after any BEGIN rule(s) have been run.) Command
line variable assignment is most useful for dynamically assigning val‐
ues to the variables AWK uses to control how input is broken into
fields and records. It is also useful for controlling state if multi‐
ple passes are needed over a single data file.
If the value of a particular element of ARGV is empty (""), gawk skips
over it.
For each input file, if a BEGINFILE rule exists, gawk executes the
associated code before processing the contents of the file. Similarly,
gawk executes the code associated with ENDFILE after processing the
file.
For each record in the input, gawk tests to see if it matches any pat‐
tern in the AWK program. For each pattern that the record matches,
gawk executes the associated action. The patterns are tested in the
order they occur in the program.
Finally, after all the input is exhausted, gawk executes the code in
the END rule(s) (if any).
Command Line Directories
According to POSIX, files named on the awk command line must be text
files. The behavior is ``undefined'' if they are not. Most versions
of awk treat a directory on the command line as a fatal error.
Starting with version 4.0 of gawk, a directory on the command line
produces a warning, but is otherwise skipped. If either of the
--posix or --traditional options is given, then gawk reverts to treat‐
ing directories on the command line as a fatal error.
VARIABLES, RECORDS AND FIELDS
AWK variables are dynamic; they come into existence when they are
first used. Their values are either floating-point numbers or
strings, or both, depending upon how they are used. AWK also has one
dimensional arrays; arrays with multiple dimensions may be simulated.
Gawk provides true arrays of arrays; see Arrays, below. Several pre-
defined variables are set as a program runs; these are described as
needed and summarized below.
Records
Normally, records are separated by newline characters. You can con‐
trol how records are separated by assigning values to the built-in
variable RS. If RS is any single character, that character separates
records. Otherwise, RS is a regular expression. Text in the input
that matches this regular expression separates the record. However,
in compatibility mode, only the first character of its string value is
used for separating records. If RS is set to the null string, then
records are separated by blank lines. When RS is set to the null
string, the newline character always acts as a field separator, in
addition to whatever value FS may have.
Fields
As each input record is read, gawk splits the record into fields,
using the value of the FS variable as the field separator. If FS is a
single character, fields are separated by that character. If FS is
the null string, then each individual character becomes a separate
field. Otherwise, FS is expected to be a full regular expression. In
the special case that FS is a single space, fields are separated by
runs of spaces and/or tabs and/or newlines. (But see the section
POSIX COMPATIBILITY, below). NOTE: The value of IGNORECASE (see
below) also affects how fields are split when FS is a regular expres‐
sion, and how records are separated when RS is a regular expression.
If the FIELDWIDTHS variable is set to a space separated list of num‐
bers, each field is expected to have fixed width, and gawk splits up
the record using the specified widths. The value of FS is ignored.
Assigning a new value to FS or FPAT overrides the use of FIELDWIDTHS.
Similarly, if the FPAT variable is set to a string representing a reg‐
ular expression, each field is made up of text that matches that regu‐
lar expression. In this case, the regular expression describes the
fields themselves, instead of the text that separates the fields.
Assigning a new value to FS or FIELDWIDTHS overrides the use of FPAT.
Each field in the input record may be referenced by its position: $1,
$2, and so on. $0 is the whole record. Fields need not be referenced
by constants:
n = 5
print $n
prints the fifth field in the input record.
The variable NF is set to the total number of fields in the input
record.
References to non-existent fields (i.e., fields after $NF) produce the
null-string. However, assigning to a non-existent field (e.g.,
$(NF+2) = 5) increases the value of NF, creates any intervening fields
with the null string as their values, and causes the value of $0 to be
recomputed, with the fields being separated by the value of OFS. Ref‐
erences to negative numbered fields cause a fatal error. Decrementing
NF causes the values of fields past the new value to be lost, and the
value of $0 to be recomputed, with the fields being separated by the
value of OFS.
Assigning a value to an existing field causes the whole record to be
rebuilt when $0 is referenced. Similarly, assigning a value to $0
causes the record to be resplit, creating new values for the fields.
Built-in Variables
Gawk's built-in variables are:
ARGC The number of command line arguments (does not include
options to gawk, or the program source).
ARGIND The index in ARGV of the current file being processed.
ARGV Array of command line arguments. The array is indexed
from 0 to ARGC - 1. Dynamically changing the contents of
ARGV can control the files used for data.
BINMODE On non-POSIX systems, specifies use of “binary” mode for
all file I/O. Numeric values of 1, 2, or 3, specify that
input files, output files, or all files, respectively,
should use binary I/O. String values of "r", or "w" spec‐
ify that input files, or output files, respectively,
should use binary I/O. String values of "rw" or "wr"
specify that all files should use binary I/O. Any other
string value is treated as "rw", but generates a warning
message.
CONVFMT The conversion format for numbers, "%.6g", by default.
ENVIRON An array containing the values of the current environment.
The array is indexed by the environment variables, each
element being the value of that variable (e.g., ENVI‐
RON["HOME"] might be "/home/arnold"). Changing this array
does not affect the environment seen by programs which
gawk spawns via redirection or the system() function.
ERRNO If a system error occurs either doing a redirection for
getline, during a read for getline, or during a close(),
then ERRNO will contain a string describing the error.
The value is subject to translation in non-English
locales.
FIELDWIDTHS A whitespace separated list of field widths. When set,
gawk parses the input into fields of fixed width, instead
of using the value of the FS variable as the field separa‐
tor. See Fields, above.
FILENAME The name of the current input file. If no files are spec‐
ified on the command line, the value of FILENAME is “-”.
However, FILENAME is undefined inside the BEGIN rule
(unless set by getline).
FNR The input record number in the current input file.
FPAT A regular expression describing the contents of the fields
in a record. When set, gawk parses the input into fields,
where the fields match the regular expression, instead of
using the value of the FS variable as the field separator.
See Fields, above.
FS The input field separator, a space by default. See
Fields, above.
FUNCTAB An array whose indices and corresponding values are the
names of all the user-defined or extension functions in
the program. NOTE: You may not use the delete statement
with the FUNCTAB array.
IGNORECASE Controls the case-sensitivity of all regular expression
and string operations. If IGNORECASE has a non-zero
value, then string comparisons and pattern matching in
rules, field splitting with FS and FPAT, record separating
with RS, regular expression matching with ~ and !~, and
the gensub(), gsub(), index(), match(), patsplit(),
split(), and sub() built-in functions all ignore case when
doing regular expression operations. NOTE: Array sub‐
scripting is not affected. However, the asort() and
asorti() functions are affected.
Thus, if IGNORECASE is not equal to zero, /aB/ matches all
of the strings "ab", "aB", "Ab", and "AB". As with all
AWK variables, the initial value of IGNORECASE is zero, so
all regular expression and string operations are normally
case-sensitive.
LINT Provides dynamic control of the --lint option from within
an AWK program. When true, gawk prints lint warnings.
When false, it does not. When assigned the string value
"fatal", lint warnings become fatal errors, exactly like
--lint=fatal. Any other true value just prints warnings.
NF The number of fields in the current input record.
NR The total number of input records seen so far.
OFMT The output format for numbers, "%.6g", by default.
OFS The output field separator, a space by default.
ORS The output record separator, by default a newline.
PREC The working precision of arbitrary precision floating-
point numbers, 53 by default.
PROCINFO The elements of this array provide access to information
about the running AWK program. On some systems, there may
be elements in the array, "group1" through "groupn" for
some n, which is the number of supplementary groups that
the process has. Use the in operator to test for these
elements. The following elements are guaranteed to be
available:
PROCINFO["egid"] The value of the getegid(2) system
call.
PROCINFO["euid"] The value of the geteuid(2) system
call.
PROCINFO["FS"] "FS" if field splitting with FS is in
effect, "FPAT" if field splitting
with FPAT is in effect, or "FIELD‐
WIDTHS" if field splitting with
FIELDWIDTHS is in effect.
PROCINFO["gid"] The value of the getgid(2) system
call.
PROCINFO["identifiers"]
A subarray, indexed by the names of
all identifiers used in the text of
the AWK program. The values indicate
what gawk knows about the identifiers
after it has finished parsing the
program; they are not updated while
the program runs. For each identi‐
fier, the value of the element is one
of the following:
"array"
The identifier is an array.
"builtin"
The identifier is a built-in
function.
"extension"
The identifier is an extension
function loaded via @load or
-l.
"scalar"
The identifier is a scalar.
"untyped"
The identifier is untyped
(could be used as a scalar or
array, gawk doesn't know yet).
"user" The identifier is a user-
defined function.
PROCINFO["pgrpid"] The process group ID of the current
process.
PROCINFO["pid"] The process ID of the current
process.
PROCINFO["ppid"] The parent process ID of the current
process.
PROCINFO["strftime"] The default time format string for
strftime().
PROCINFO["uid"] The value of the getuid(2) system
call.
PROCINFO["version"] the version of gawk.
The following elements are present if loading dynamic
extensions is available:
PROCINFO["api_major"]
The major version of the extension API.
PROCINFO["api_minor"]
The minor version of the extension API.
The following elements are available if MPFR support is
compiled into gawk:
PROCINFO["gmp_version"]
The version of the GNU MP library used for arbi‐
trary precision number support in gawk.
PROCINFO["mpfr_version"]
The version of the GNU MPFR library used for arbi‐
trary precision number support in gawk.
PROCINFO["prec_max"]
The maximum precision supported by the GNU MPFR
library for arbitrary precision floating-point num‐
bers.
PROCINFO["prec_min"]
The minimum precision allowed by the GNU MPFR
library for arbitrary precision floating-point num‐
bers.
The following elements may set by a program to change
gawk's behavior:
PROCINFO["command", "pty"]
Use a pseudo-tty for two-way communication with
command instead of setting up two one-way pipes.
PROCINFO["input", "READ_TIMEOUT"]
The timeout in milliseconds for reading data from
input, where input is a redirection string or a
filename. A value of zero or less than zero means
no timeout.
PROCINFO["sorted_in"]
If this element exists in PROCINFO, then its value
controls the order in which array elements are tra‐
versed in for loops. Supported values are
"@ind_str_asc", "@ind_num_asc", "@val_type_asc",
"@val_str_asc", "@val_num_asc", "@ind_str_desc",
"@ind_num_desc", "@val_type_desc", "@val_str_desc",
"@val_num_desc", and "@unsorted". The value can
also be the name of any comparison function defined
as follows:
function cmp_func(i1, v1, i2, v2)
where i1 and i2 are the indices, and v1 and v2 are
the corresponding values of the two elements being
compared. It should return a number less than,
equal to, or greater than 0, depending on how the
elements of the array are to be ordered.
ROUNDMODE The rounding mode to use for arbitrary precision arith‐
metic on numbers, by default "N" (IEEE-754 roundTiesToEven
mode). The accepted values are "N" or "n" for
roundTiesToEven, "U" or "u" for roundTowardPositive, "D"
or "d" for roundTowardNegative, "Z" or "z" for roundTo‐
wardZero, and if your version of GNU MPFR library supports
it, "A" or "a" for roundTiesToAway.
RS The input record separator, by default a newline.
RT The record terminator. Gawk sets RT to the input text
that matched the character or regular expression specified
by RS.
RSTART The index of the first character matched by match(); 0 if
no match. (This implies that character indices start at
one.)
RLENGTH The length of the string matched by match(); -1 if no
match.
SUBSEP The character used to separate multiple subscripts in
array elements, by default "\034".
SYMTAB An array whose indices are the names of all currently
defined global variables and arrays in the program. The
array may be used for indirect access to read or write the
value of a variable:
foo = 5
SYMTAB["foo"] = 4
print foo # prints 4
The isarray() function may be used to test if an element
in SYMTAB is an array. You may not use the delete state‐
ment with the SYMTAB array.
TEXTDOMAIN The text domain of the AWK program; used to find the
localized translations for the program's strings.
Arrays
Arrays are subscripted with an expression between square brackets ([
and ]). If the expression is an expression list (expr, expr ...)
then the array subscript is a string consisting of the concatenation
of the (string) value of each expression, separated by the value of
the SUBSEP variable. This facility is used to simulate multiply
dimensioned arrays. For example:
i = "A"; j = "B"; k = "C"
x[i, j, k] = "hello, world\n"
assigns the string "hello, world\n" to the element of the array x
which is indexed by the string "A\034B\034C". All arrays in AWK are
associative, i.e., indexed by string values.
The special operator in may be used to test if an array has an index
consisting of a particular value:
if (val in array)
print array[val]
If the array has multiple subscripts, use (i, j) in array.
The in construct may also be used in a for loop to iterate over all
the elements of an array. However, the (i, j) in array construct only
works in tests, not in for loops.
An element may be deleted from an array using the delete statement.
The delete statement may also be used to delete the entire contents of
an array, just by specifying the array name without a subscript.
gawk supports true multidimensional arrays. It does not require that
such arrays be ``rectangular'' as in C or C++. For example:
a[1] = 5
a[2][1] = 6
a[2][2] = 7
NOTE: You may need to tell gawk that an array element is really a sub‐
array in order to use it where gawk expects an array (such as in the
second argument to split()). You can do this by creating an element
in the subarray and then deleting it with the delete statement.
Variable Typing And Conversion
Variables and fields may be (floating point) numbers, or strings, or
both. How the value of a variable is interpreted depends upon its
context. If used in a numeric expression, it will be treated as a
number; if used as a string it will be treated as a string.
To force a variable to be treated as a number, add 0 to it; to force
it to be treated as a string, concatenate it with the null string.
Uninitialized variables have the numeric value 0 and the string value
"" (the null, or empty, string).
When a string must be converted to a number, the conversion is accom‐
plished using strtod(3). A number is converted to a string by using
the value of CONVFMT as a format string for sprintf(3), with the
numeric value of the variable as the argument. However, even though
all numbers in AWK are floating-point, integral values are always con‐
verted as integers. Thus, given
CONVFMT = "%2.2f"
a = 12
b = a ""
the variable b has a string value of "12" and not "12.00".
NOTE: When operating in POSIX mode (such as with the --posix option),
beware that locale settings may interfere with the way decimal numbers
are treated: the decimal separator of the numbers you are feeding to
gawk must conform to what your locale would expect, be it a comma (,)
or a period (.).
Gawk performs comparisons as follows: If two variables are numeric,
they are compared numerically. If one value is numeric and the other
has a string value that is a “numeric string,” then comparisons are
also done numerically. Otherwise, the numeric value is converted to a
string and a string comparison is performed. Two strings are com‐
pared, of course, as strings.
Note that string constants, such as "57", are not numeric strings,
they are string constants. The idea of “numeric string” only applies
to fields, getline input, FILENAME, ARGV elements, ENVIRON elements
and the elements of an array created by split() or patsplit() that are
numeric strings. The basic idea is that user input, and only user
input, that looks numeric, should be treated that way.
Octal and Hexadecimal Constants
You may use C-style octal and hexadecimal constants in your AWK pro‐
gram source code. For example, the octal value 011 is equal to deci‐
mal 9, and the hexadecimal value 0x11 is equal to decimal 17.
String Constants
String constants in AWK are sequences of characters enclosed between
double quotes (like "value"). Within strings, certain escape
sequences are recognized, as in C. These are:
\\ A literal backslash.
\a The “alert” character; usually the ASCII BEL character.
\b Backspace.
\f Form-feed.
\n Newline.
\r Carriage return.
\t Horizontal tab.
\v Vertical tab.
\xhex digits
The character represented by the string of hexadecimal digits
following the \x. As in ISO C, all following hexadecimal digits
are considered part of the escape sequence. (This feature should
tell us something about language design by committee.) E.g.,
"\x1B" is the ASCII ESC (escape) character.
\ddd The character represented by the 1-, 2-, or 3-digit sequence of
octal digits. E.g., "\033" is the ASCII ESC (escape) character.
\c The literal character c.
The escape sequences may also be used inside constant regular expres‐
sions (e.g., /[ \t\f\n\r\v]/ matches whitespace characters).
In compatibility mode, the characters represented by octal and hexa‐
decimal escape sequences are treated literally when used in regular
expression constants. Thus, /a\52b/ is equivalent to /a\*b/.
PATTERNS AND ACTIONS
AWK is a line-oriented language. The pattern comes first, and then
the action. Action statements are enclosed in { and }. Either the
pattern may be missing, or the action may be missing, but, of course,
not both. If the pattern is missing, the action is executed for every
single record of input. A missing action is equivalent to
{ print }
which prints the entire record.
Comments begin with the # character, and continue until the end of the
line. Blank lines may be used to separate statements. Normally, a
statement ends with a newline, however, this is not the case for lines
ending in a comma, {, ?, :, &&, or ||. Lines ending in do or else
also have their statements automatically continued on the following
line. In other cases, a line can be continued by ending it with a
“\”, in which case the newline is ignored.
Multiple statements may be put on one line by separating them with a
“;”. This applies to both the statements within the action part of a
pattern-action pair (the usual case), and to the pattern-action state‐
ments themselves.
Patterns
AWK patterns may be one of the following:
BEGIN
END
BEGINFILE
ENDFILE
/regular expression/
relational expression
pattern && pattern
pattern || pattern
pattern ? pattern : pattern
(pattern)
! pattern
pattern1, pattern2
BEGIN and END are two special kinds of patterns which are not tested
against the input. The action parts of all BEGIN patterns are merged
as if all the statements had been written in a single BEGIN rule.
They are executed before any of the input is read. Similarly, all the
END rules are merged, and executed when all the input is exhausted (or
when an exit statement is executed). BEGIN and END patterns cannot be
combined with other patterns in pattern expressions. BEGIN and END
patterns cannot have missing action parts.
BEGINFILE and ENDFILE are additional special patterns whose bodies are
executed before reading the first record of each command line input
file and after reading the last record of each file. Inside the
BEGINFILE rule, the value of ERRNO will be the empty string if the
file was opened successfully. Otherwise, there is some problem with
the file and the code should use nextfile to skip it. If that is not
done, gawk produces its usual fatal error for files that cannot be
opened.
For /regular expression/ patterns, the associated statement is exe‐
cuted for each input record that matches the regular expression. Reg‐
ular expressions are the same as those in egrep(1), and are summarized
below.
A relational expression may use any of the operators defined below in
the section on actions. These generally test whether certain fields
match certain regular expressions.
The &&, ||, and ! operators are logical AND, logical OR, and logical
NOT, respectively, as in C. They do short-circuit evaluation, also as
in C, and are used for combining more primitive pattern expressions.
As in most languages, parentheses may be used to change the order of
evaluation.
The ?: operator is like the same operator in C. If the first pattern
is true then the pattern used for testing is the second pattern, oth‐
erwise it is the third. Only one of the second and third patterns is
evaluated.
The pattern1, pattern2 form of an expression is called a range pat‐
tern. It matches all input records starting with a record that
matches pattern1, and continuing until a record that matches pattern2,
inclusive. It does not combine with any other sort of pattern expres‐
sion.
Regular Expressions
Regular expressions are the extended kind found in egrep. They are
composed of characters as follows:
c Matches the non-metacharacter c.
\c Matches the literal character c.
. Matches any character including newline.
^ Matches the beginning of a string.
$ Matches the end of a string.
[abc...] A character list: matches any of the characters abc....
You may include a range of characters by separating them
with a dash.
[^abc...] A negated character list: matches any character except
abc....
r1|r2 Alternation: matches either r1 or r2.
r1r2 Concatenation: matches r1, and then r2.
r+ Matches one or more r's.
r* Matches zero or more r's.
r? Matches zero or one r's.
(r) Grouping: matches r.
r{n}
r{n,}
r{n,m} One or two numbers inside braces denote an interval expres‐
sion. If there is one number in the braces, the preceding
regular expression r is repeated n times. If there are two
numbers separated by a comma, r is repeated n to m times.
If there is one number followed by a comma, then r is
repeated at least n times.
\y Matches the empty string at either the beginning or the end
of a word.
\B Matches the empty string within a word.
\< Matches the empty string at the beginning of a word.
\> Matches the empty string at the end of a word.
\s Matches any whitespace character.
\S Matches any nonwhitespace character.
\w Matches any word-constituent character (letter, digit, or
underscore).
\W Matches any character that is not word-constituent.
\` Matches the empty string at the beginning of a buffer
(string).
\' Matches the empty string at the end of a buffer.
The escape sequences that are valid in string constants (see String
Constants) are also valid in regular expressions.
Character classes are a feature introduced in the POSIX standard. A
character class is a special notation for describing lists of charac‐
ters that have a specific attribute, but where the actual characters
themselves can vary from country to country and/or from character set
to character set. For example, the notion of what is an alphabetic
character differs in the USA and in France.
A character class is only valid in a regular expression inside the
brackets of a character list. Character classes consist of [:, a key‐
word denoting the class, and :]. The character classes defined by the
POSIX standard are:
[:alnum:] Alphanumeric characters.
[:alpha:] Alphabetic characters.
[:blank:] Space or tab characters.
[:cntrl:] Control characters.
[:digit:] Numeric characters.
[:graph:] Characters that are both printable and visible. (A space
is printable, but not visible, while an a is both.)
[:lower:] Lowercase alphabetic characters.
[:print:] Printable characters (characters that are not control char‐
acters.)
[:punct:] Punctuation characters (characters that are not letter,
digits, control characters, or space characters).
[:space:] Space characters (such as space, tab, and formfeed, to name
a few).
[:upper:] Uppercase alphabetic characters.
[:xdigit:] Characters that are hexadecimal digits.
For example, before the POSIX standard, to match alphanumeric charac‐
ters, you would have had to write /[A-Za-z0-9]/. If your character
set had other alphabetic characters in it, this would not match them,
and if your character set collated differently from ASCII, this might
not even match the ASCII alphanumeric characters. With the POSIX
character classes, you can write /[[:alnum:]]/, and this matches the
alphabetic and numeric characters in your character set, no matter
what it is.
Two additional special sequences can appear in character lists. These
apply to non-ASCII character sets, which can have single symbols
(called collating elements) that are represented with more than one
character, as well as several characters that are equivalent for col‐
lating, or sorting, purposes. (E.g., in French, a plain “e” and a
grave-accented “`” are equivalent.)
Collating Symbols
A collating symbol is a multi-character collating element
enclosed in [. and .]. For example, if ch is a collating ele‐
ment, then [[.ch.]] is a regular expression that matches this
collating element, while [ch] is a regular expression that
matches either c or h.
Equivalence Classes
An equivalence class is a locale-specific name for a list of
characters that are equivalent. The name is enclosed in [= and
=]. For example, the name e might be used to represent all of
“e”, “´”, and “`”. In this case, [[=e=]] is a regular expres‐
sion that matches any of e, ´, or `.
These features are very valuable in non-English speaking locales. The
library functions that gawk uses for regular expression matching cur‐
rently only recognize POSIX character classes; they do not recognize
collating symbols or equivalence classes.
The \y, \B, \<, \>, \s, \S, \w, \W, \`, and \' operators are specific
to gawk; they are extensions based on facilities in the GNU regular
expression libraries.
The various command line options control how gawk interprets charac‐
ters in regular expressions.
No options
In the default case, gawk provides all the facilities of POSIX
regular expressions and the GNU regular expression operators
described above.
--posix
Only POSIX regular expressions are supported, the GNU operators
are not special. (E.g., \w matches a literal w).
--traditional
Traditional UNIX awk regular expressions are matched. The GNU
operators are not special, and interval expressions are not
available. Characters described by octal and hexadecimal
escape sequences are treated literally, even if they represent
regular expression metacharacters.
--re-interval
Allow interval expressions in regular expressions, even if
--traditional has been provided.
Actions
Action statements are enclosed in braces, { and }. Action statements
consist of the usual assignment, conditional, and looping statements
found in most languages. The operators, control statements, and
input/output statements available are patterned after those in C.
Operators
The operators in AWK, in order of decreasing precedence, are:
(...) Grouping
$ Field reference.
++ -- Increment and decrement, both prefix and postfix.
^ Exponentiation (** may also be used, and **= for the
assignment operator).
+ - ! Unary plus, unary minus, and logical negation.
* / % Multiplication, division, and modulus.
+ - Addition and subtraction.
space String concatenation.
| |& Piped I/O for getline, print, and printf.
< > <= >= != ==
The regular relational operators.
~ !~ Regular expression match, negated match. NOTE: Do not use
a constant regular expression (/foo/) on the left-hand
side of a ~ or !~. Only use one on the right-hand side.
The expression /foo/ ~ exp has the same meaning as (($0 ~
/foo/) ~ exp). This is usually not what you want.
in Array membership.
&& Logical AND.
|| Logical OR.
?: The C conditional expression. This has the form expr1 ?
expr2 : expr3. If expr1 is true, the value of the expres‐
sion is expr2, otherwise it is expr3. Only one of expr2
and expr3 is evaluated.
= += -= *= /= %= ^=
Assignment. Both absolute assignment (var = value) and
operator-assignment (the other forms) are supported.
Control Statements
The control statements are as follows:
if (condition) statement [ else statement ]
while (condition) statement
do statement while (condition)
for (expr1; expr2; expr3) statement
for (var in array) statement
break
continue
delete array[index]
delete array
exit [ expression ]
{ statements }
switch (expression) {
case value|regex : statement
...
[ default: statement ]
}
I/O Statements
The input/output statements are as follows:
close(file [, how]) Close file, pipe or co-process. The optional
how should only be used when closing one end of
a two-way pipe to a co-process. It must be a
string value, either "to" or "from".
getline Set $0 from next input record; set NF, NR, FNR,
RT.
getline <file Set $0 from next record of file; set NF, RT.
getline var Set var from next input record; set NR, FNR, RT.
getline var <file Set var from next record of file, RT.
command | getline [var]
Run command piping the output either into $0 or
var, as above, and RT.
command |& getline [var]
Run command as a co-process piping the output
either into $0 or var, as above, and RT. Co-
processes are a gawk extension. (command can
also be a socket. See the subsection Special
File Names, below.)
next Stop processing the current input record. The
next input record is read and processing starts
over with the first pattern in the AWK program.
Upon reaching the end of the input data, gawk
executes any END rule(s).
nextfile Stop processing the current input file. The
next input record read comes from the next input
file. FILENAME and ARGIND are updated, FNR is
reset to 1, and processing starts over with the
first pattern in the AWK program. Upon reaching
the end of the input data, gawk executes any END
rule(s).
print Print the current record. The output record is
terminated with the value of ORS.
print expr-list Print expressions. Each expression is separated
by the value of OFS. The output record is ter‐
minated with the value of ORS.
print expr-list >file Print expressions on file. Each expression is
separated by the value of OFS. The output
record is terminated with the value of ORS.
printf fmt, expr-list Format and print. See The printf Statement,
below.
printf fmt, expr-list >file
Format and print on file.
system(cmd-line) Execute the command cmd-line, and return the
exit status. (This may not be available on non-
POSIX systems.) See the manual for the full
details on the exit status.
fflush([file]) Flush any buffers associated with the open out‐
put file or pipe file. If file is missing or if
it is the null string, then flush all open out‐
put files and pipes.
Additional output redirections are allowed for print and printf.
print ... >> file
Appends output to the file.
print ... | command
Writes on a pipe.
print ... |& command
Sends data to a co-process or socket. (See also the subsection
Special File Names, below.)
The getline command returns 1 on success, 0 on end of file, and -1 on
an error. Upon an error, ERRNO is set to a string describing the
problem.
NOTE: Failure in opening a two-way socket results in a non-fatal error
being returned to the calling function. If using a pipe, co-process,
or socket to getline, or from print or printf within a loop, you must
use close() to create new instances of the command or socket. AWK
does not automatically close pipes, sockets, or co-processes when they
return EOF.
The printf Statement
The AWK versions of the printf statement and sprintf() function (see
below) accept the following conversion specification formats:
%c A single character. If the argument used for %c is numeric,
it is treated as a character and printed. Otherwise, the
argument is assumed to be a string, and the only first charac‐
ter of that string is printed.
%d, %i A decimal number (the integer part).
%e, %E A floating point number of the form [-]d.dddddde[+-]dd. The
%E format uses E instead of e.
%f, %F A floating point number of the form [-]ddd.dddddd. If the
system library supports it, %F is available as well. This is
like %f, but uses capital letters for special “not a number”
and “infinity” values. If %F is not available, gawk uses %f.
%g, %G Use %e or %f conversion, whichever is shorter, with nonsignif‐
icant zeros suppressed. The %G format uses %E instead of %e.
%o An unsigned octal number (also an integer).
%u An unsigned decimal number (again, an integer).
%s A character string.
%x, %X An unsigned hexadecimal number (an integer). The %X format
uses ABCDEF instead of abcdef.
%% A single % character; no argument is converted.
Optional, additional parameters may lie between the % and the control
letter:
count$ Use the count'th argument at this point in the formatting.
This is called a positional specifier and is intended primarily
for use in translated versions of format strings, not in the
original text of an AWK program. It is a gawk extension.
- The expression should be left-justified within its field.
space For numeric conversions, prefix positive values with a space,
and negative values with a minus sign.
+ The plus sign, used before the width modifier (see below), says
to always supply a sign for numeric conversions, even if the
data to be formatted is positive. The + overrides the space
modifier.
# Use an “alternate form” for certain control letters. For %o,
supply a leading zero. For %x, and %X, supply a leading 0x or
0X for a nonzero result. For %e, %E, %f and %F, the result
always contains a decimal point. For %g, and %G, trailing
zeros are not removed from the result.
0 A leading 0 (zero) acts as a flag, that indicates output should
be padded with zeroes instead of spaces. This applies only to
the numeric output formats. This flag only has an effect when
the field width is wider than the value to be printed.
' A single quote character instructs gawk to insert the locale's
thousands-separator character into decimal numbers, and to also
use the locale's decimal point character with floating point
formats. This requires correct locale support in the C library
and in the definition of the current locale.
width The field should be padded to this width. The field is nor‐
mally padded with spaces. With the 0 flag, it is padded with
zeroes.
.prec A number that specifies the precision to use when printing.
For the %e, %E, %f and %F, formats, this specifies the number
of digits you want printed to the right of the decimal point.
For the %g, and %G formats, it specifies the maximum number of
significant digits. For the %d, %i, %o, %u, %x, and %X for‐
mats, it specifies the minimum number of digits to print. For
%s, it specifies the maximum number of characters from the
string that should be printed.
The dynamic width and prec capabilities of the ISO C printf() routines
are supported. A * in place of either the width or prec specifica‐
tions causes their values to be taken from the argument list to printf
or sprintf(). To use a positional specifier with a dynamic width or
precision, supply the count$ after the * in the format string. For
example, "%3$*2$.*1$s".
Special File Names
When doing I/O redirection from either print or printf into a file, or
via getline from a file, gawk recognizes certain special filenames
internally. These filenames allow access to open file descriptors
inherited from gawk's parent process (usually the shell). These file
names may also be used on the command line to name data files. The
filenames are:
- The standard input.
/dev/stdin The standard input.
/dev/stdout The standard output.
/dev/stderr The standard error output.
/dev/fd/n The file associated with the open file descriptor n.
These are particularly useful for error messages. For example:
print "You blew it!" > "/dev/stderr"
whereas you would otherwise have to use
print "You blew it!" | "cat 1>&2"
The following special filenames may be used with the |& co-process
operator for creating TCP/IP network connections:
/inet/tcp/lport/rhost/rport
/inet4/tcp/lport/rhost/rport
/inet6/tcp/lport/rhost/rport
Files for a TCP/IP connection on local port lport to remote
host rhost on remote port rport. Use a port of 0 to have the
system pick a port. Use /inet4 to force an IPv4 connection,
and /inet6 to force an IPv6 connection. Plain /inet uses the
system default (most likely IPv4).
/inet/udp/lport/rhost/rport
/inet4/udp/lport/rhost/rport
/inet6/udp/lport/rhost/rport
Similar, but use UDP/IP instead of TCP/IP.
Numeric Functions
AWK has the following built-in arithmetic functions:
atan2(y, x) Return the arctangent of y/x in radians.
cos(expr) Return the cosine of expr, which is in radians.
exp(expr) The exponential function.
int(expr) Truncate to integer.
log(expr) The natural logarithm function.
rand() Return a random number N, between 0 and 1, such that 0 ≤
N < 1.
sin(expr) Return the sine of expr, which is in radians.
sqrt(expr) Return the square root of expr.
srand([expr]) Use expr as the new seed for the random number genera‐
tor. If no expr is provided, use the time of day.
Return the previous seed for the random number genera‐
tor.
String Functions
Gawk has the following built-in string functions:
asort(s [, d [, how] ]) Return the number of elements in the source
array s. Sort the contents of s using gawk's
normal rules for comparing values, and replace
the indices of the sorted values s with
sequential integers starting with 1. If the
optional destination array d is specified,
first duplicate s into d, and then sort d,
leaving the indices of the source array s
unchanged. The optional string how controls
the direction and the comparison mode. Valid
values for how are any of the strings valid
for PROCINFO["sorted_in"]. It can also be the
name of a user-defined comparison function as
described in PROCINFO["sorted_in"].
asorti(s [, d [, how] ])
Return the number of elements in the source
array s. The behavior is the same as that of
asort(), except that the array indices are
used for sorting, not the array values. When
done, the array is indexed numerically, and
the values are those of the original indices.
The original values are lost; thus provide a
second array if you wish to preserve the orig‐
inal. The purpose of the optional string how
is the same as described in asort() above.
gensub(r, s, h [, t]) Search the target string t for matches of the
regular expression r. If h is a string begin‐
ning with g or G, then replace all matches of
r with s. Otherwise, h is a number indicating
which match of r to replace. If t is not sup‐
plied, use $0 instead. Within the replacement
text s, the sequence \n, where n is a digit
from 1 to 9, may be used to indicate just the
text that matched the n'th parenthesized sub‐
expression. The sequence \0 represents the
entire matched text, as does the character &.
Unlike sub() and gsub(), the modified string
is returned as the result of the function, and
the original target string is not changed.
gsub(r, s [, t]) For each substring matching the regular
expression r in the string t, substitute the
string s, and return the number of substitu‐
tions. If t is not supplied, use $0. An & in
the replacement text is replaced with the text
that was actually matched. Use \& to get a
literal &. (This must be typed as "\\&"; see
GAWK: Effective AWK Programming for a fuller
discussion of the rules for &'s and back‐
slashes in the replacement text of sub(),
gsub(), and gensub().)
index(s, t) Return the index of the string t in the string
s, or 0 if t is not present. (This implies
that character indices start at one.) It is a
fatal error to use a regexp constant for t.
length([s]) Return the length of the string s, or the
length of $0 if s is not supplied. As a non-
standard extension, with an array argument,
length() returns the number of elements in the
array.
match(s, r [, a]) Return the position in s where the regular
expression r occurs, or 0 if r is not present,
and set the values of RSTART and RLENGTH.
Note that the argument order is the same as
for the ~ operator: str ~ re. If array a is
provided, a is cleared and then elements 1
through n are filled with the portions of s
that match the corresponding parenthesized
subexpression in r. The 0'th element of a
contains the portion of s matched by the
entire regular expression r. Subscripts a[n,
"start"], and a[n, "length"] provide the
starting index in the string and length
respectively, of each matching substring.
patsplit(s, a [, r [, seps] ])
Split the string s into the array a and the
separators array seps on the regular expres‐
sion r, and return the number of fields. Ele‐
ment values are the portions of s that matched
r. The value of seps[i] is the separator that
appeared in front of a[i+1]. If r is omitted,
FPAT is used instead. The arrays a and seps
are cleared first. Splitting behaves identi‐
cally to field splitting with FPAT, described
above.
split(s, a [, r [, seps] ])
Split the string s into the array a and the
separators array seps on the regular expres‐
sion r, and return the number of fields. If r
is omitted, FS is used instead. The arrays a
and seps are cleared first. seps[i] is the
field separator matched by r between a[i] and
a[i+1]. If r is a single space, then leading
whitespace in s goes into the extra array ele‐
ment seps[0] and trailing whitespace goes into
the extra array element seps[n], where n is
the return value of split(s, a, r, seps).
Splitting behaves identically to field split‐
ting, described above.
sprintf(fmt, expr-list) Print expr-list according to fmt, and return
the resulting string.
strtonum(str) Examine str, and return its numeric value. If
str begins with a leading 0, treat it as an
octal number. If str begins with a leading 0x
or 0X, treat it as a hexadecimal number. Oth‐
erwise, assume it is a decimal number.
sub(r, s [, t]) Just like gsub(), but replace only the first
matching substring.
substr(s, i [, n]) Return the at most n-character substring of s
starting at i. If n is omitted, use the rest
of s.
tolower(str) Return a copy of the string str, with all the
uppercase characters in str translated to
their corresponding lowercase counterparts.
Non-alphabetic characters are left unchanged.
toupper(str) Return a copy of the string str, with all the
lowercase characters in str translated to
their corresponding uppercase counterparts.
Non-alphabetic characters are left unchanged.
Gawk is multibyte aware. This means that index(), length(), substr()
and match() all work in terms of characters, not bytes.
Time Functions
Since one of the primary uses of AWK programs is processing log files
that contain time stamp information, gawk provides the following func‐
tions for obtaining time stamps and formatting them.
mktime(datespec)
Turn datespec into a time stamp of the same form as returned
by systime(), and return the result. The datespec is a
string of the form YYYY MM DD HH MM SS[ DST]. The contents
of the string are six or seven numbers representing respec‐
tively the full year including century, the month from 1 to
12, the day of the month from 1 to 31, the hour of the day
from 0 to 23, the minute from 0 to 59, the second from 0 to
60, and an optional daylight saving flag. The values of
these numbers need not be within the ranges specified; for
example, an hour of -1 means 1 hour before midnight. The
origin-zero Gregorian calendar is assumed, with year 0 pre‐
ceding year 1 and year -1 preceding year 0. The time is
assumed to be in the local timezone. If the daylight saving
flag is positive, the time is assumed to be daylight saving
time; if zero, the time is assumed to be standard time; and
if negative (the default), mktime() attempts to determine
whether daylight saving time is in effect for the specified
time. If datespec does not contain enough elements or if
the resulting time is out of range, mktime() returns -1.
strftime([format [, timestamp[, utc-flag]]])
Format timestamp according to the specification in format.
If utc-flag is present and is non-zero or non-null, the
result is in UTC, otherwise the result is in local time.
The timestamp should be of the same form as returned by sys‐
time(). If timestamp is missing, the current time of day is
used. If format is missing, a default format equivalent to
the output of date(1) is used. The default format is avail‐
able in PROCINFO["strftime"]. See the specification for the
strftime() function in ISO C for the format conversions that
are guaranteed to be available.
systime() Return the current time of day as the number of seconds
since the Epoch (1970-01-01 00:00:00 UTC on POSIX systems).
Bit Manipulations Functions
Gawk supplies the following bit manipulation functions. They work by
converting double-precision floating point values to uintmax_t inte‐
gers, doing the operation, and then converting the result back to
floating point. The functions are:
and(v1, v2 [, ...]) Return the bitwise AND of the values provided in
the argument list. There must be at least two.
compl(val) Return the bitwise complement of val.
lshift(val, count) Return the value of val, shifted left by count
bits.
or(v1, v2 [, ...]) Return the bitwise OR of the values provided in
the argument list. There must be at least two.
rshift(val, count) Return the value of val, shifted right by count
bits.
xor(v1, v2 [, ...]) Return the bitwise XOR of the values provided in
the argument list. There must be at least two.
Type Function
The following function is for use with multidimensional arrays.
isarray(x)
Return true if x is an array, false otherwise.
Internationalization Functions
The following functions may be used from within your AWK program for
translating strings at run-time. For full details, see GAWK: Effec‐
tive AWK Programming.
bindtextdomain(directory [, domain])
Specify the directory where gawk looks for the .gmo files, in
case they will not or cannot be placed in the ``standard''
locations (e.g., during testing). It returns the directory
where domain is ``bound.''
The default domain is the value of TEXTDOMAIN. If directory is
the null string (""), then bindtextdomain() returns the current
binding for the given domain.
dcgettext(string [, domain [, category]])
Return the translation of string in text domain domain for
locale category category. The default value for domain is the
current value of TEXTDOMAIN. The default value for category is
"LC_MESSAGES".
If you supply a value for category, it must be a string equal
to one of the known locale categories described in GAWK: Effec‐
tive AWK Programming. You must also supply a text domain. Use
TEXTDOMAIN if you want to use the current domain.
dcngettext(string1, string2, number [, domain [, category]])
Return the plural form used for number of the translation of
string1 and string2 in text domain domain for locale category
category. The default value for domain is the current value of
TEXTDOMAIN. The default value for category is "LC_MESSAGES".
If you supply a value for category, it must be a string equal
to one of the known locale categories described in GAWK: Effec‐
tive AWK Programming. You must also supply a text domain. Use
TEXTDOMAIN if you want to use the current domain.
USER-DEFINED FUNCTIONS
Functions in AWK are defined as follows:
function name(parameter list) { statements }
Functions are executed when they are called from within expressions in
either patterns or actions. Actual parameters supplied in the func‐
tion call are used to instantiate the formal parameters declared in
the function. Arrays are passed by reference, other variables are
passed by value.
Since functions were not originally part of the AWK language, the pro‐
vision for local variables is rather clumsy: They are declared as
extra parameters in the parameter list. The convention is to separate
local variables from real parameters by extra spaces in the parameter
list. For example:
function f(p, q, a, b) # a and b are local
{
...
}
/abc/ { ... ; f(1, 2) ; ... }
The left parenthesis in a function call is required to immediately
follow the function name, without any intervening whitespace. This
avoids a syntactic ambiguity with the concatenation operator. This
restriction does not apply to the built-in functions listed above.
Functions may call each other and may be recursive. Function parame‐
ters used as local variables are initialized to the null string and
the number zero upon function invocation.
Use return expr to return a value from a function. The return value
is undefined if no value is provided, or if the function returns by
“falling off” the end.
As a gawk extension, functions may be called indirectly. To do this,
assign the name of the function to be called, as a string, to a vari‐
able. Then use the variable as if it were the name of a function,
prefixed with an @ sign, like so:
function myfunc()
{
print "myfunc called"
...
}
{ ...
the_func = "myfunc"
@the_func() # call through the_func to myfunc
...
}
As of version 4.1.2, this works with user-defined functions, built-in
functions, and extension functions.
If --lint has been provided, gawk warns about calls to undefined func‐
tions at parse time, instead of at run time. Calling an undefined
function at run time is a fatal error.
The word func may be used in place of function, although this is dep‐
recated.
DYNAMICALLY LOADING NEW FUNCTIONS
You can dynamically add new built-in functions to the running gawk
interpreter with the @load statement. The full details are beyond the
scope of this manual page; see GAWK: Effective AWK Programming.
SIGNALS
The gawk profiler accepts two signals. SIGUSR1 causes it to dump a
profile and function call stack to the profile file, which is either
awkprof.out, or whatever file was named with the --profile option. It
then continues to run. SIGHUP causes gawk to dump the profile and
function call stack and then exit.
INTERNATIONALIZATION
String constants are sequences of characters enclosed in double
quotes. In non-English speaking environments, it is possible to mark
strings in the AWK program as requiring translation to the local natu‐
ral language. Such strings are marked in the AWK program with a lead‐
ing underscore (“_”). For example,
gawk 'BEGIN { print "hello, world" }'
always prints hello, world. But,
gawk 'BEGIN { print _"hello, world" }'
might print bonjour, monde in France.
There are several steps involved in producing and running a localiz‐
able AWK program.
1. Add a BEGIN action to assign a value to the TEXTDOMAIN variable to
set the text domain to a name associated with your program:
BEGIN { TEXTDOMAIN = "myprog" }
This allows gawk to find the .gmo file associated with your pro‐
gram. Without this step, gawk uses the messages text domain,
which likely does not contain translations for your program.
2. Mark all strings that should be translated with leading under‐
scores.
3. If necessary, use the dcgettext() and/or bindtextdomain() func‐
tions in your program, as appropriate.
4. Run gawk --gen-pot -f myprog.awk > myprog.pot to generate a .pot
file for your program.
5. Provide appropriate translations, and build and install the corre‐
sponding .gmo files.
The internationalization features are described in full detail in
GAWK: Effective AWK Programming.
POSIX COMPATIBILITY
A primary goal for gawk is compatibility with the POSIX standard, as
well as with the latest version of Brian Kernighan's awk. To this
end, gawk incorporates the following user visible features which are
not described in the AWK book, but are part of the Brian Kernighan's
version of awk, and are in the POSIX standard.
The book indicates that command line variable assignment happens when
awk would otherwise open the argument as a file, which is after the
BEGIN rule is executed. However, in earlier implementations, when
such an assignment appeared before any file names, the assignment
would happen before the BEGIN rule was run. Applications came to
depend on this “feature.” When awk was changed to match its documen‐
tation, the -v option for assigning variables before program execution
was added to accommodate applications that depended upon the old
behavior. (This feature was agreed upon by both the Bell Laboratories
and the GNU developers.)
When processing arguments, gawk uses the special option “--” to signal
the end of arguments. In compatibility mode, it warns about but oth‐
erwise ignores undefined options. In normal operation, such arguments
are passed on to the AWK program for it to process.
The AWK book does not define the return value of srand(). The POSIX
standard has it return the seed it was using, to allow keeping track
of random number sequences. Therefore srand() in gawk also returns
its current seed.
Other new features are: The use of multiple -f options (from MKS awk);
the ENVIRON array; the \a, and \v escape sequences (done originally in
gawk and fed back into the Bell Laboratories version); the tolower()
and toupper() built-in functions (from the Bell Laboratories version);
and the ISO C conversion specifications in printf (done first in the
Bell Laboratories version).
HISTORICAL FEATURES
There is one feature of historical AWK implementations that gawk sup‐
ports: It is possible to call the length() built-in function not only
with no argument, but even without parentheses! Thus,
a = length # Holy Algol 60, Batman!
is the same as either of
a = length()
a = length($0)
Using this feature is poor practice, and gawk issues a warning about
its use if --lint is specified on the command line.
GNU EXTENSIONS
Gawk has a too-large number of extensions to POSIX awk. They are
described in this section. All the extensions described here can be
disabled by invoking gawk with the --traditional or --posix options.
The following features of gawk are not available in POSIX awk.
· No path search is performed for files named via the -f option.
Therefore the AWKPATH environment variable is not special.
· There is no facility for doing file inclusion (gawk's @include mech‐
anism).
· There is no facility for dynamically adding new functions written in
C (gawk's @load mechanism).
· The \x escape sequence. (Disabled with --posix.)
· The ability to continue lines after ? and :. (Disabled with
--posix.)
· Octal and hexadecimal constants in AWK programs.
· The ARGIND, BINMODE, ERRNO, LINT, RT and TEXTDOMAIN variables are
not special.
· The IGNORECASE variable and its side-effects are not available.
· The FIELDWIDTHS variable and fixed-width field splitting.
· The FPAT variable and field splitting based on field values.
· The PROCINFO array is not available.
· The use of RS as a regular expression.
· The special file names available for I/O redirection are not recog‐
nized.
· The |& operator for creating co-processes.
· The BEGINFILE and ENDFILE special patterns are not available.
· The ability to split out individual characters using the null string
as the value of FS, and as the third argument to split().
· An optional fourth argument to split() to receive the separator
texts.
· The optional second argument to the close() function.
· The optional third argument to the match() function.
· The ability to use positional specifiers with printf and sprintf().
· The ability to pass an array to length().
· The and(), asort(), asorti(), bindtextdomain(), compl(), dcget‐
text(), dcngettext(), gensub(), lshift(), mktime(), or(), pat‐
split(), rshift(), strftime(), strtonum(), systime() and xor() func‐
tions.
· Localizable strings.
The AWK book does not define the return value of the close() function.
Gawk's close() returns the value from fclose(3), or pclose(3), when
closing an output file or pipe, respectively. It returns the
process's exit status when closing an input pipe. The return value is
-1 if the named file, pipe or co-process was not opened with a redi‐
rection.
When gawk is invoked with the --traditional option, if the fs argument
to the -F option is “t”, then FS is set to the tab character. Note
that typing gawk -F\t ... simply causes the shell to quote the “t,”
and does not pass “\t” to the -F option. Since this is a rather ugly
special case, it is not the default behavior. This behavior also does
not occur if --posix has been specified. To really get a tab charac‐
ter as the field separator, it is best to use single quotes: gawk
-F'\t' ....
ENVIRONMENT VARIABLES
The AWKPATH environment variable can be used to provide a list of
directories that gawk searches when looking for files named via the
-f, --file, -i and --include options. If the initial search fails,
the path is searched again after appending .awk to the filename.
The AWKLIBPATH environment variable can be used to provide a list of
directories that gawk searches when looking for files named via the -l
and --load options.
The GAWK_READ_TIMEOUT environment variable can be used to specify a
timeout in milliseconds for reading input from a terminal, pipe or
two-way communication including sockets.
For connection to a remote host via socket, GAWK_SOCK_RETRIES controls
the number of retries, and GAWK_MSEC_SLEEP and the interval between
retries. The interval is in milliseconds. On systems that do not sup‐
port usleep(3), the value is rounded up to an integral number of sec‐
onds.
If POSIXLY_CORRECT exists in the environment, then gawk behaves
exactly as if --posix had been specified on the command line. If
--lint has been specified, gawk issues a warning message to this
effect.
EXIT STATUS
If the exit statement is used with a value, then gawk exits with the
numeric value given to it.
Otherwise, if there were no problems during execution, gawk exits with
the value of the C constant EXIT_SUCCESS. This is usually zero.
If an error occurs, gawk exits with the value of the C constant
EXIT_FAILURE. This is usually one.
If gawk exits because of a fatal error, the exit status is 2. On non-
POSIX systems, this value may be mapped to EXIT_FAILURE.
VERSION INFORMATION
This man page documents gawk, version 4.1.
AUTHORS
The original version of UNIX awk was designed and implemented by
Alfred Aho, Peter Weinberger, and Brian Kernighan of Bell Laborato‐
ries. Brian Kernighan continues to maintain and enhance it.
Paul Rubin and Jay Fenlason, of the Free Software Foundation, wrote
gawk, to be compatible with the original version of awk distributed in
Seventh Edition UNIX. John Woods contributed a number of bug fixes.
David Trueman, with contributions from Arnold Robbins, made gawk com‐
patible with the new version of UNIX awk. Arnold Robbins is the cur‐
rent maintainer.
See GAWK: Effective AWK Programming for a full list of the contribu‐
tors to gawk and its documentation.
See the README file in the gawk distribution for up-to-date informa‐
tion about maintainers and which ports are currently supported.
BUG REPORTS
If you find a bug in gawk, please send electronic mail to bug-
gawk@gnu.org. Please include your operating system and its revision,
the version of gawk (from gawk --version), which C compiler you used
to compile it, and a test program and data that are as small as possi‐
ble for reproducing the problem.
Before sending a bug report, please do the following things. First,
verify that you have the latest version of gawk. Many bugs (usually
subtle ones) are fixed at each release, and if yours is out of date,
the problem may already have been solved. Second, please see if set‐
ting the environment variable LC_ALL to LC_ALL=C causes things to
behave as you expect. If so, it's a locale issue, and may or may not
really be a bug. Finally, please read this man page and the reference
manual carefully to be sure that what you think is a bug really is,
instead of just a quirk in the language.
Whatever you do, do NOT post a bug report in comp.lang.awk. While the
gawk developers occasionally read this newsgroup, posting bug reports
there is an unreliable way to report bugs. Instead, please use the
electronic mail addresses given above. Really.
If you're using a GNU/Linux or BSD-based system, you may wish to sub‐
mit a bug report to the vendor of your distribution. That's fine, but
please send a copy to the official email address as well, since
there's no guarantee that the bug report will be forwarded to the gawk
maintainer.
BUGS
The -F option is not necessary given the command line variable assign‐
ment feature; it remains only for backwards compatibility.
SEE ALSO
egrep(1), sed(1), getpid(2), getppid(2), getpgrp(2), getuid(2),
geteuid(2), getgid(2), getegid(2), getgroups(2), usleep(3)
The AWK Programming Language, Alfred V. Aho, Brian W. Kernighan, Peter
J. Weinberger, Addison-Wesley, 1988. ISBN 0-201-07981-X.
GAWK: Effective AWK Programming, Edition 4.1, shipped with the gawk
source. The current version of this document is available online at
http://www.gnu.org/software/gawk/manual.
EXAMPLES
Print and sort the login names of all users:
BEGIN { FS = ":" }
{ print $1 | "sort" }
Count lines in a file:
{ nlines++ }
END { print nlines }
Precede each line by its number in the file:
{ print FNR, $0 }
Concatenate and line number (a variation on a theme):
{ print NR, $0 }
Run an external command for particular lines of data:
tail -f access_log |
awk '/myhome.html/ { system("nmap " $1 ">> logdir/myhome.html") }'
ACKNOWLEDGEMENTS
Brian Kernighan provided valuable assistance during testing and debug‐
ging. We thank him.
COPYING PERMISSIONS
Copyright © 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1999, 2001, 2002, 2003, 2004, 2005, 2007, 2009, 2010, 2011, 2012,
2013, 2014, 2016 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of this
manual page provided the copyright notice and this permission notice
are preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual page under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this man‐
ual page into another language, under the above conditions for modi‐
fied versions, except that this permission notice may be stated in a
translation approved by the Foundation.
Free Software Foundation Mar 7 2016 GAWK(1)
- vim
常用工作模式
普通模式
插入模式
命令模式
进入插入模式
a 于光标后
A 于当前段落段尾
i 于光标前
I 于当前段落段首
o 于当前行后创建新的空白行
O 与当前行前创建新的空白行
光标操作
h 左一位
j 下一行
k 上一行
l 右一位
gg 至文件首行
G 至文件末尾
nG 至第n行
^ 至当前行首字符
$ 至当前行尾字符
fx 至当前行的下一位x
Fx 至当前行的上一位x
w 向右一个单词
x 删除光标当前字符
dd 删除一行
ndd 删除n行
d$ 删除光标至行尾
J 删换行符，合并为一行
u 撤销上一步
rx 光标当前字符替换为x
yy 复制当前行
p 粘贴至当前行之后
q 粘贴至当前行之前
查找与替换
普通模式下输入:进入命令模式完成替换功能
:s/root/admin/ 光标当前行中第一个root换为admin
:s/root/admin/g 当前行中所有root换为admin
:3,5s/sbin/bin/g 3-5行间所有替换
:%s/nologin/fault/g 所有行替换
保存与退出
:q! 不保存退出
:wq! 保存并退出
😡 保存并退出
:w 保存
:w b.txt 另存
其他
命令模式下输入
:set number 或set nu 添加行号
:set ignorecase 忽略大小写
:split 一个文件不同行同时编辑
窗口切换
ctrl+w+h 左
ctrl+w+l 右
ctrl+w+j 上
ctrl+w+k 下
SYNOPSIS
vim [options] [file ..]
vim [options] -
vim [options] -t tag
vim [options] -q [errorfile]
ex
view
gvim gview evim eview
rvim rview rgvim rgview
DESCRIPTION
Vim is a text editor that is upwards compatible to Vi. It can be used
to edit all kinds of plain text. It is especially useful for editing
programs.
There are a lot of enhancements above Vi: multi level undo, multi win‐
dows and buffers, syntax highlighting, command line editing, filename
completion, on-line help, visual selection, etc.. See ":help
vi_diff.txt" for a summary of the differences between Vim and Vi.
While running Vim a lot of help can be obtained from the on-line help
system, with the ":help" command. See the ON-LINE HELP section below.
Most often Vim is started to edit a single file with the command
vim file
More generally Vim is started with:
vim [options] [filelist]
If the filelist is missing, the editor will start with an empty buf‐
fer. Otherwise exactly one out of the following four may be used to
choose one or more files to be edited.
file .. A list of filenames. The first one will be the current
file and read into the buffer. The cursor will be posi‐
tioned on the first line of the buffer. You can get to
the other files with the ":next" command. To edit a file
that starts with a dash, precede the filelist with "--".
- The file to edit is read from stdin. Commands are read
from stderr, which should be a tty.
-t {tag} The file to edit and the initial cursor position depends
on a "tag", a sort of goto label. {tag} is looked up in
the tags file, the associated file becomes the current
file and the associated command is executed. Mostly this
is used for C programs, in which case {tag} could be a
function name. The effect is that the file containing
that function becomes the current file and the cursor is
positioned on the start of the function. See ":help
tag-commands".
-q [errorfile]
Start in quickFix mode. The file [errorfile] is read and
the first error is displayed. If [errorfile] is omitted,
the filename is obtained from the 'errorfile' option (de‐
faults to "AztecC.Err" for the Amiga, "errors.err" on
other systems). Further errors can be jumped to with the
":cn" command. See ":help quickfix".
Vim behaves differently, depending on the name of the command (the ex‐
ecutable may still be the same file).
vim The "normal" way, everything is default.
ex Start in Ex mode. Go to Normal mode with the ":vi" command.
Can also be done with the "-e" argument.
view Start in read-only mode. You will be protected from writing
the files. Can also be done with the "-R" argument.
gvim gview
The GUI version. Starts a new window. Can also be done
with the "-g" argument.
evim eview
The GUI version in easy mode. Starts a new window. Can
also be done with the "-y" argument.
rvim rview rgvim rgview
Like the above, but with restrictions. It will not be pos‐
sible to start shell commands, or suspend Vim. Can also be
done with the "-Z" argument.
OPTIONS
The options may be given in any order, before or after filenames. Op‐
tions without an argument can be combined after a single dash.
+[num] For the first file the cursor will be positioned on line
"num". If "num" is missing, the cursor will be positioned
on the last line.
+/{pat} For the first file the cursor will be positioned in the
line with the first occurrence of {pat}. See ":help
search-pattern" for the available search patterns.
+{command}
-c {command}
{command} will be executed after the first file has been
read. {command} is interpreted as an Ex command. If the
{command} contains spaces it must be enclosed in double
quotes (this depends on the shell that is used). Example:
Vim "+set si" main.c
Note: You can use up to 10 "+" or "-c" commands.
-S {file} {file} will be sourced after the first file has been read.
This is equivalent to -c "source {file}". {file} cannot
start with '-'. If {file} is omitted "Session.vim" is
used (only works when -S is the last argument).
--cmd {command}
Like using "-c", but the command is executed just before
processing any vimrc file. You can use up to 10 of these
commands, independently from "-c" commands.
-A If Vim has been compiled with ARABIC support for editing
right-to-left oriented files and Arabic keyboard mapping,
this option starts Vim in Arabic mode, i.e. 'arabic' is
set. Otherwise an error message is given and Vim aborts.
-b Binary mode. A few options will be set that makes it pos‐
sible to edit a binary or executable file.
-C Compatible. Set the 'compatible' option. This will make
Vim behave mostly like Vi, even though a .vimrc file ex‐
ists.
-d Start in diff mode. There should be two, three or four
file name arguments. Vim will open all the files and show
differences between them. Works like vimdiff(1).
-d {device} Open {device} for use as a terminal. Only on the Amiga.
Example: "-d con:20/30/600/150".
-D Debugging. Go to debugging mode when executing the first
command from a script.
-e Start Vim in Ex mode, just like the executable was called
"ex".
-E Start Vim in improved Ex mode, just like the executable
was called "exim".
-f Foreground. For the GUI version, Vim will not fork and
detach from the shell it was started in. On the Amiga,
Vim is not restarted to open a new window. This option
should be used when Vim is executed by a program that will
wait for the edit session to finish (e.g. mail). On the
Amiga the ":sh" and ":!" commands will not work.
--nofork Foreground. For the GUI version, Vim will not fork and
detach from the shell it was started in.
-F If Vim has been compiled with FKMAP support for editing
right-to-left oriented files and Farsi keyboard mapping,
this option starts Vim in Farsi mode, i.e. 'fkmap' and
'rightleft' are set. Otherwise an error message is given
and Vim aborts.
-g If Vim has been compiled with GUI support, this option en‐
ables the GUI. If no GUI support was compiled in, an er‐
ror message is given and Vim aborts.
-h Give a bit of help about the command line arguments and
options. After this Vim exits.
-H If Vim has been compiled with RIGHTLEFT support for edit‐
ing right-to-left oriented files and Hebrew keyboard map‐
ping, this option starts Vim in Hebrew mode, i.e. 'hkmap'
and 'rightleft' are set. Otherwise an error message is
given and Vim aborts.
-i {viminfo}
Specifies the filename to use when reading or writing the
viminfo file, instead of the default "~/.viminfo". This
can also be used to skip the use of the .viminfo file, by
giving the name "NONE".
-L Same as -r.
-l Lisp mode. Sets the 'lisp' and 'showmatch' options on.
-m Modifying files is disabled. Resets the 'write' option.
You can still modify the buffer, but writing a file is not
possible.
-M Modifications not allowed. The 'modifiable' and 'write'
options will be unset, so that changes are not allowed and
files can not be written. Note that these options can be
set to enable making modifications.
-N No-compatible mode. Resets the 'compatible' option. This
will make Vim behave a bit better, but less Vi compatible,
even though a .vimrc file does not exist.
-n No swap file will be used. Recovery after a crash will be
impossible. Handy if you want to edit a file on a very
slow medium (e.g. floppy). Can also be done with ":set
uc=0". Can be undone with ":set uc=200".
-nb Become an editor server for NetBeans. See the docs for
details.
-o[N] Open N windows stacked. When N is omitted, open one win‐
dow for each file.
-O[N] Open N windows side by side. When N is omitted, open one
window for each file.
-p[N] Open N tab pages. When N is omitted, open one tab page
for each file.
-R Read-only mode. The 'readonly' option will be set. You
can still edit the buffer, but will be prevented from ac‐
cidentally overwriting a file. If you do want to over‐
write a file, add an exclamation mark to the Ex command,
as in ":w!". The -R option also implies the -n option
(see above). The 'readonly' option can be reset with
":set noro". See ":help 'readonly'".
-r List swap files, with information about using them for re‐
covery.
-r {file} Recovery mode. The swap file is used to recover a crashed
editing session. The swap file is a file with the same
filename as the text file with ".swp" appended. See
":help recovery".
-s Silent mode. Only when started as "Ex" or when the "-e"
option was given before the "-s" option.
-s {scriptin}
The script file {scriptin} is read. The characters in the
file are interpreted as if you had typed them. The same
can be done with the command ":source! {scriptin}". If
the end of the file is reached before the editor exits,
further characters are read from the keyboard.
-T {terminal}
Tells Vim the name of the terminal you are using. Only
required when the automatic way doesn't work. Should be a
terminal known to Vim (builtin) or defined in the termcap
or terminfo file.
-u {vimrc} Use the commands in the file {vimrc} for initializations.
All the other initializations are skipped. Use this to
edit a special kind of files. It can also be used to skip
all initializations by giving the name "NONE". See ":help
initialization" within vim for more details.
-U {gvimrc} Use the commands in the file {gvimrc} for GUI initializa‐
tions. All the other GUI initializations are skipped. It
can also be used to skip all GUI initializations by giving
the name "NONE". See ":help gui-init" within vim for more
details.
-V[N] Verbose. Give messages about which files are sourced and
for reading and writing a viminfo file. The optional num‐
ber N is the value for 'verbose'. Default is 10.
-v Start Vim in Vi mode, just like the executable was called
"vi". This only has effect when the executable is called
"ex".
-w {scriptout}
All the characters that you type are recorded in the file
{scriptout}, until you exit Vim. This is useful if you
want to create a script file to be used with "vim -s" or
":source!". If the {scriptout} file exists, characters
are appended.
-W {scriptout}
Like -w, but an existing file is overwritten.
-x Use encryption when writing files. Will prompt for a
crypt key.
-X Don't connect to the X server. Shortens startup time in a
terminal, but the window title and clipboard will not be
used.
-y Start Vim in easy mode, just like the executable was
called "evim" or "eview". Makes Vim behave like a click-
and-type editor.
-Z Restricted mode. Works like the executable starts with
"r".
-- Denotes the end of the options. Arguments after this will
be handled as a file name. This can be used to edit a
filename that starts with a '-'.
--echo-wid GTK GUI only: Echo the Window ID on stdout.
--help Give a help message and exit, just like "-h".
--literal Take file name arguments literally, do not expand wild‐
cards. This has no effect on Unix where the shell expands
wildcards.
--noplugin Skip loading plugins. Implied by -u NONE.
--remote Connect to a Vim server and make it edit the files given
in the rest of the arguments. If no server is found a
warning is given and the files are edited in the current
Vim.
--remote-expr {expr}
Connect to a Vim server, evaluate {expr} in it and print
the result on stdout.
--remote-send {keys}
Connect to a Vim server and send {keys} to it.
--remote-silent
As --remote, but without the warning when no server is
found.
--remote-wait
As --remote, but Vim does not exit until the files have
been edited.
--remote-wait-silent
As --remote-wait, but without the warning when no server
is found.
--serverlist
List the names of all Vim servers that can be found.
--servername {name}
Use {name} as the server name. Used for the current Vim,
unless used with a --remote argument, then it's the name
of the server to connect to.
--socketid {id}
GTK GUI only: Use the GtkPlug mechanism to run gvim in an‐
other window.
--version Print version information and exit.
ON-LINE HELP
Type ":help" in Vim to get started. Type ":help subject" to get help
on a specific subject. For example: ":help ZZ" to get help for the
"ZZ" command. Use <Tab> and CTRL-D to complete subjects (":help cmd‐
line-completion"). Tags are present to jump from one place to another
(sort of hypertext links, see ":help"). All documentation files can
be viewed in this way, for example ":help syntax.txt".
FILES
/usr/share/vim/vim81/doc/*.txt
The Vim documentation files. Use ":help doc-file-list"
to get the complete list.
/usr/share/vim/vim81/doc/tags
The tags file used for finding information in the docu‐
mentation files.
/usr/share/vim/vim81/syntax/syntax.vim
System wide syntax initializations.
/usr/share/vim/vim81/syntax/*.vim
Syntax files for various languages.
/etc/vimrc System wide Vim initializations.
~/.vimrc Your personal Vim initializations.
/etc/gvimrc System wide gvim initializations.
~/.gvimrc Your personal gvim initializations.
/usr/share/vim/vim81/optwin.vim
Script used for the ":options" command, a nice way to
view and set options.
/usr/share/vim/vim81/menu.vim
System wide menu initializations for gvim.
/usr/share/vim/vim81/bugreport.vim
Script to generate a bug report. See ":help bugs".
/usr/share/vim/vim81/filetype.vim
Script to detect the type of a file by its name. See
":help 'filetype'".
/usr/share/vim/vim81/scripts.vim
Script to detect the type of a file by its contents.
See ":help 'filetype'".
/usr/share/vim/vim81/print/*.ps
Files used for PostScript printing.
For recent info read the VIM home page:
<URL:http://www.vim.org/>
SEE ALSO
vimtutor(1)
AUTHOR
Most of Vim was made by Bram Moolenaar, with a lot of help from oth‐
ers. See ":help credits" in Vim.
Vim is based on Stevie, worked on by: Tim Thompson, Tony Andrews and
G.R. (Fred) Walter. Although hardly any of the original code remains.
BUGS
Probably. See ":help todo" for a list of known problems.
Note that a number of things that may be regarded as bugs by some, are
in fact caused by a too-faithful reproduction of Vi's behaviour. And
if you think other things are bugs "because Vi does it differently",
you should take a closer look at the vi_diff.txt file (or type :help
vi_diff.txt when in Vim). Also have a look at the 'compatible' and
'cpoptions' options.
2006 Apr 11 VIM(1)
- echo
SYNOPSIS
echo [SHORT-OPTION]... [STRING]...
echo LONG-OPTION
DESCRIPTION
Echo the STRING(s) to standard output.
-n do not output the trailing newline
-e enable interpretation of backslash escapes
-E disable interpretation of backslash escapes (default)
--help display this help and exit
--version
output version information and exit
If -e is in effect, the following sequences are recognized:
\\ backslash
\a alert (BEL)
\b backspace
\c produce no further output
\e escape
\f form feed
\n new line
\r carriage return
\t horizontal tab
\v vertical tab
\0NNN byte with octal value NNN (1 to 3 digits)
\xHH byte with hexadecimal value HH (1 to 2 digits)
NOTE: your shell may have its own version of echo, which usually su‐
persedes the version described here. Please refer to your shell's
documentation for details about the options it supports.
AUTHOR
Written by Brian Fox and Chet Ramey.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/echo>
or available locally via: info '(coreutils) echo invocation'
GNU coreutils 8.31 March 2019 ECHO(1)