[!NOTE] references:
CHARACTER REGULAR EXPRESSION EXPLANATION Space or tab characters only
Printable and visible characters
Lower-case alphabetic characters
Printable (non-Control) characters
Upper-case alphabetic characters
Hexadecimal digit characters
execute multiple sed commands
[!TIP]
Copy -e command
Append the editing commands specified by the command argument to the list of commands. references:
example : show only root and nobody in /etc/passwd
-e :
Copy $ sed -n -e '/^root/p' -e '/^nobody/p' /etc/passwd
nobody:*:-2:-2:Unprivileged User:/var/empty:/usr/bin/ false
root:*:0:0:System Administrator:/var/root:/bin/sh ; :
Copy $ sed -n -e '/^root/p;/^nobody/p' /etc/passwd
nobody:*:-2:-2:Unprivileged User:/var/empty:/usr/bin/ false
root:*:0:0:System Administrator:/var/root:/bin/sh '{}' :
Copy $ sed -n '{
/^root/p
/^nobody/p
}' /etc/passwd
nobody:*:-2:-2:Unprivileged User:/var/empty:/usr/bin/ false
root:*:0:0:System Administrator:/var/root:/bin/sh range
specific line
until empty line
Copy $ top -bn1 | sed -n '0,/^\s*$/p'
top - 03:41:45 up 258 days, 19:05, 1 user, load average: 2.33, 0.92, 0.95
Tasks: 856 total, 2 running, 447 sleeping, 0 stopped, 36 zombie
%Cpu(s ): 0.3 us, 0.4 sy, 0.0 ni, 99.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 52802012+total, 11152644+free, 24536944 used, 39195673+buff/cache
KiB Swap: 0 total, 0 free, 0 used. 49137280+avail Mem
or
Copy $ top -bn1 | sed -e '/^$/Q'
top - 03:45:55 up 258 days, 19:09, 1 user, load average: 0.17, 0.51, 0.77
Tasks: 857 total, 2 running, 448 sleeping, 0 stopped, 36 zombie
%Cpu(s ): 0.1 us, 0.4 sy, 0.0 ni, 99.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 52802012+total, 11151089+free, 24546520 used, 39196272+buff/cache
KiB Swap: 0 total, 0 free, 0 used. 49136291+avail Mem n~m range
n to end lines : n,$ <opt>
m lines starting with n : n, +m <opt>
start n skip m via ~ :
pattern matches comments start frmo 1, print every 2 lines
start from 2, print every 2 lines
start from 1, print every 3 lines
start from 2, print every 3 lines
pattern matches range
between pattern_1 to pattern_2 : /pattern_1/,/pattern_2/ <opt>
first line to pattern_2 : 0,/pattern_2/ <opt>
from pattern to first empty line
Copy $ top -bn1 | sed -n '/^top.*/,/^\s*$/p'
top - 03:49:02 up 258 days, 19:13, 1 user, load average: 0.43, 0.41, 0.68
Tasks: 853 total, 1 running, 448 sleeping, 0 stopped, 36 zombie
%Cpu(s ): 0.3 us, 0.4 sy, 0.0 ni, 99.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 52802012+total, 11150942+free, 24543500 used, 39196720+buff/cache
KiB Swap: 0 total, 0 free, 0 used. 49136582+avail Mem
print
print all lines
print every line twice
Copy $ sed 'p' employee.txt
101,John Doe,CEO
101,John Doe,CEO
102,Jason Smith,IT Manager
102,Jason Smith,IT Manager
103,Raj Reddy,Sysadmin
103,Raj Reddy,Sysadmin
104,Anand Ram,Developer
104,Anand Ram,Developer
105,Jane Miller,Sales Manager
105,Jane Miller,Sales Manager print all lines : $ sed -n 'p' employee.txt
range print
print the 2nd line : $ sed -n '2 p' employee.txt
n,m range
print 1~4 lines : $ sed -n '1,4 p' employee.txt
print all lines since the 2nd line: $ sed -n '2,$ p' employee.txt
~ to skip lines
print only odd numbered lines : sed -n '1~2 p' employee.txt
+ ( n, +m ) : sed -n 'n,+m p' employee.txt
print matched pattern
find pattern to the end :
Copy $ sed -n '/Raj/,$ p' employee.txt
103,Raj Reddy,Sysadmin
104,Anand Ram,Developer
105,Jane Miller,Sales Manager find pattern and line after the matches line :
Copy $ sed -n '/Raj/, +1 p' employee.txt
103,Raj Reddy,Sysadmin
104,Anand Ram,Developer find pattern to 4th line :
Copy $ sed -n '/Raj/,4 p' employee.txt
103,Raj Reddy,Sysadmin
104,Anand Ram,Developer find pattern until find another pattern ( Jason to Anand ) :
Copy $ sed -n '/Jason/,/Anand/p' employee.txt
102,Jason Smith,IT Manager
103,Raj Reddy,Sysadmin
104,Anand Ram,Developer print line number of matched pattern
[!NOTE|label:references:]
Copy # original
$ printf "%s\r\n\r\n%s\r\n%s\r\n\r\n%s\r\n" 1 2 3 4 | command cat -A | nl
1 1^M $
2 ^M $
3 2^M $
4 3^M $
5 ^M $
6 4^M $
# result
$ printf "%s\r\n\r\n%s\r\n%s\r\n\r\n%s\r\n" 1 2 3 4 | sed -n '/^\s*\r$/ ='
2
5
# or
$ sed -n '/^\s*\r$/ =' < <( printf "%s\r\n\r\n%s\r\n%s\r\n\r\n%s\r\n" 1 2 3 4 )
2
5
# first matched line number
$ printf "%s\r\n\r\n%s\r\n%s\r\n%s\r\n" 1 2 3 4 | sed -n '/^\s*\r$/ =' | head -n1
2
# last matched line number
$ printf "%s\r\n\r\n%s\r\n%s\r\n\r\n%s\r\n" 1 2 3 4 | sed -n '/^\s*\r$/ =' | tail -n1
5 or
Copy # via sed
$ sed -n '10,20{=;p}'
## or ##
$ nl file.txt | sed -n '10,20p'
## or ##
$ sed -n '10,20{=;p}' file.txt | sed '{N; s/\n/ /}'
# via awk
$ awk 'FNR==10,FNR==20 {print FNR ":" $0}' file.txt
## or ##
$ awk 'FNR >= 10 {print FNR ":" $0}; FNR == 20 {exit}' file.txt
## or ##
$ awk -v OFS=: 'FNR >= 10 {print FILENAME, FNR, $0}; FNR == 20 {nextfile}' ./*.txt delete
delete all
Copy $ sed 'd' employee.txt range delete
delete the 2nd line : $ sed '2 d' /path/to/file
delete between 1 and 4 lines : $ sed '1,4 d' /path/to/file
conditional delete
delete all empty lines: $ sed '/^$/ d' /path/to/file
delete all comment lines : $ sed '/^#/ d' /path/to/file
substitute
substitute-flags
multiple replaces
Copy $ sed '{
s/Developer/IT Manager/
s/Manager/Director/
}' employee.txt
101,John Doe,CEO
102,Jason Smith,IT Director
103,Raj Reddy,Sysadmin
104,Anand Ram,IT Director
105,Jane Miller,Sales Director get matched pattern
&
When & is used in the replacement-string, it replaces it with whatever text matched the original-string or the regular-expression.
Copy $ sed 's/^[0-9][0-9][0-9]/<&>/g' employee.txt
< 1 01> ,John Doe,CEO
< 1 02> ,Jason Smith,IT Manager
< 1 03> ,Raj Reddy,Sysadmin
< 1 04> ,Anand Ram,Developer
< 1 05> ,Jane Miller,Sales Manager substitution grouping
Copy $ sed 's/^\([0-9][0-9][0-9]\).*/<\1>/g' employee.txt
< 1 01>
< 1 02>
< 1 03>
< 1 04>
< 1 05> or via -r
Copy $ sed -r 's/^([0-9][0-9][0-9]).*/<\1>/g' employee.txt
< 1 01>
< 1 02>
< 1 03>
< 1 04>
< 1 05>
# or
$ sed -nr 's/^([0-9][0-9][0-9])(.*)/<\1>\2/gp' employee.txt
< 1 01> ,John Doe,CEO
< 1 02> ,Jason Smith,IT Manager
< 1 03> ,Raj Reddy,Sysadmin
< 1 04> ,Anand Ram,Developer
< 1 05> ,Jane Miller,Sales Manager cheatsheet
get first matching patten ( for CERTIFICATE )
[!TIP]
sample.crt
Copy $ cat sample.crt
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
second paragraph
-----END CERTIFICATE----- regular pattern
Copy $ cat sample.crt | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p'
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
second paragraph
-----END CERTIFICATE-----
# or for short
$ cat sample.crt | sed -ne '/-BEGIN/,/-END/p'
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
second paragraph
-----END CERTIFICATE----- get first
[!TIP]
more :
Copy # or `-n /../p`
# `-n` `p`
# | |
# v v
$ cat sample.crt | sed -n '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p; /-END CERTIFICATE-/q'
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE-----
# or `/../!d`
# no `-n` `!d`
# | |
# v v
$ cat sample.crt | sed '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/!d; /-END CERTIFICATE-/q'
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE-----
# or for short
$ cat sample.crt | sed '/-END CERTIFICATE-/q'
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE-----
# or
$ cat sample.crt | sed '/-END/q'
-----BEGIN CERTIFICATE-----
first paragraph
-----END CERTIFICATE----- remove both '#' and empty lines
[!NOTE|label:references:]
Copy $ .. | sed -r '/^(#.*)$/d' | sed -r '/^\s*$/d'
# or
$ .. | sed -r '/^(#.*)$/d;/^\s*$/d'
# or
$ .. | sed -r '/(^#.*)|(^\s*)$/d' example
Copy $ ldapsearch CN=marslo DN | sed -r '/^(#.*)$/d;/^\s*$/d'
dn: CN=marslo,OU=Workers,DC=company,DC=com remove tailing spaces
[!TIP|label:available patterns]
Copy $ cal | cat -pp -A
····January·2024····␊
Su·Mo·Tu·We·Th·Fr·Sa␊
····1··2··3··4··5··6␊
·7··8··9·10·11·12·13␊
14·15·16·17·18·19·20␊
21·22·23·24·25·26·27␊
28·29·30·31·········␊
····················␊
# remove empty line
$ cal | sed -r '/^(#.*)$/d;/^\s*$/d' | cat -pp -A
····January·2024····␊
Su·Mo·Tu·We·Th·Fr·Sa␊
····1··2··3··4··5··6␊
·7··8··9·10·11·12·13␊
14·15·16·17·18·19·20␊
21·22·23·24·25·26·27␊
28·29·30·31·········␊
# remove trailing spaces
$ cal | sed 's/[[:space:]]*$//' | cat -pp -A
····January·2024␊
Su·Mo·Tu·We·Th·Fr·Sa␊
····1··2··3··4··5··6␊
·7··8··9·10·11·12·13␊
14·15·16·17·18·19·20␊
21·22·23·24·25·26·27␊
28·29·30·31␊
␊ show top summary
[!NOTE] see sed until empty line
contains empty line
Copy $ top -bn1 | sed -n '0,/^\s*$/p'
top - 03:41:45 up 258 days, 19:05, 1 user, load average: 2.33, 0.92, 0.95
Tasks: 856 total, 2 running, 447 sleeping, 0 stopped, 36 zombie
%Cpu(s ): 0.3 us, 0.4 sy, 0.0 ni, 99.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 52802012+total, 11152644+free, 24536944 used, 39195673+buff/cache
KiB Swap: 0 total, 0 free, 0 used. 49137280+avail Mem
without empty line
[!TIP] references:
manual:
The "q" command prints the current line again in less the -n flag was used on the command line and exits the script completely
Copy q[exit-code]
( quit ) Exit sed without processing any more commands or input.
Q[exit-code]
(quit) This command is the same as q, but will not print the contents of pattern space. Like q, it provides the ability to return an exit code to the caller.
Copy $ top -bn1 | sed -e '/^$/Q'
top - 03:45:55 up 258 days, 19:09, 1 user, load average: 0.17, 0.51, 0.77
Tasks: 857 total, 2 running, 448 sleeping, 0 stopped, 36 zombie
%Cpu(s ): 0.1 us, 0.4 sy, 0.0 ni, 99.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 52802012+total, 11151089+free, 24546520 used, 39196272+buff/cache
KiB Swap: 0 total, 0 free, 0 used. 49136291+avail Mem escape
[!NOTE|label:references:]
[\ to \](https://stackoverflow.com/a/67170003/2940319)
Copy $ echo "\(\)" | sed 's/\\/\\\\\\/g'
\\\(\\\ ) more
Copy alias rxvt = 'urxvt -fg' \' '#111111' \' ' -bg ' \' '#111111' \' '
# │ │┊┊| │┊┊│ │┊┊│ │┊┊│
# └─STRING──┘┊┊└─STRIN─┘┊┊└─STR─┘┊┊└─STRIN─┘┊┊│
# ┊┊ ┊┊ ┊┊ ┊┊│
# ┊┊ ┊┊ ┊┊ ┊┊│
# └┴─────────┴┴───┰───┴┴─────────┴┘│
# All escaped single quotes │
# │
# ?
alias rc=' sed '"'"':a;N;$!ba;s/\n/, /g'"'"
alias rc=' sed '\'':a;N;$!ba;s/\n/, /g' \' tricky
add ' or " to strings
[!NOTE|label:references:]
Copy $ GIT_OPT= "-a -b --c=1 2 3 -d=4 5 6"
$ GIT_OPT= $( echo "${GIT_OPT}" |
sed -r 's/\s+-/\n-/g' |
sed -r "s/^([^=]+)=(.+)$/\1='\2'/g" |
sed -e 'N;s/\n/ /'
)
$ echo $GIT_OPT
-a -b --c= '1 2 3' -d= '4 5 6'
$ GIT_OPT= "--c=1 2 3 --d=4 5 6"
$ GIT_OPT= $( echo "${GIT_OPT}" |
sed -r 's/\s+--/\n--/g' |
sed -r "s/^([^=]+)=(.+)$/\1='\2'/g" |
sed -e 'N;s/\n/ /'
)
$ echo $GIT_OPT
--c = '1 2 3' --d = '4 5 6'
$ GIT_OPT= "--c=1 2 3 --d=4 5 6"
$ GIT_OPT= $( echo "${GIT_OPT}" |
sed -r 's/\s+--/\n--/g' |
sed -r "s/^([^=]+)=(.+)$/\1=\"\2\"/g" |
sed -e 'N;s/\n/ /'
)
$ echo $GIT_OPT
--c = "1 2 3" --d = "4 5 6" Last updated 7 months ago