Docs
  • Docs
  • 归档

    • Docs » 开发文档 » sed cheatsheet

    categories: Handbook tags: Linux Geek Tools Shell

    1437字 3分钟

    #sed

    ##tldr

    sh
    sed -i "[range]s/[patern]/[replacement]/[options]" file_*
sed -i "2,5s|[patern]|[replacement]|[options]" file_*

    ###Search for text

    Search for a string and only print the lines that were matched

    sh
    $ sed -n '/hello/p' file.txt

    Case insensitive search

    sh
    $ sed -n '/hello/Ip' file.txt

    ###Sed Usage

    Syntax

    shell
    $ sed [options] command [input-file]

    With pipeline

    sh
    $ cat report.txt | sed 's/Nick/John/g'
    sh
    $ echo '123abc' | sed 's/[0-9]+//g'

    ###Option Examples

    Option Example Description
    -i sed -ibak ’s/On/Off/’ php.ini Backup and modify input file directly
    -E sed -E ’s/[0-9]+//g’ input-file Use extended regular expressions
    -n sed -n ‘3 p’ config.conf Suppress default pattern space printing
    -f sed -f script.sed config.conf Execute sed script file
    -e sed -e ‘command1’ -e ‘command2’ input-file Execute multiple sed commands

    ###Multiple commands

    sh
    $ echo "hello world" | sed -e 's/h/H/g' -e 's/w/W/g'
Hello World

    Use -e to execute multiple sed commands

    ###Sed script

    sh
    $ echo 's/h/H/g' >> hello.sed
$ echo 's/w/W/g' >> hello.sed
$ echo "hello world" | sed -f hello.sed
Hello World

    Use -f to execute sed script file

    ###Examples

    sh
    $ sed 's/old/new/g' file.txt
$ sed 's/old/new/g' file.txt > new.txt
$ sed 's/old/new/g' -i file.txt
$ sed 's/old/new/g' -i.backup file.txt

    ###Sed Usage

    Syntax

    shell
    $ sed [options] command [input-file]

    With pipeline

    sh
    $ cat report.txt | sed 's/Nick/John/g'
    sh
    $ echo '123abc' | sed 's/[0-9]+//g'

    ###Option Examples

    Option Example Description
    -i sed -ibak ’s/On/Off/’ php.ini Backup and modify input file directly
    -E sed -E ’s/[0-9]+//g’ input-file Use extended regular expressions
    -n sed -n ‘3 p’ config.conf Suppress default pattern space printing
    -f sed -f script.sed config.conf Execute sed script file
    -e sed -e ‘command1’ -e ‘command2’ input-file Execute multiple sed commands

    ###Multiple commands

    sh
    $ echo "hello world" | sed -e 's/h/H/g' -e 's/w/W/g'
Hello World

    Use -e to execute multiple sed commands

    ###Sed script

    sh
    $ echo 's/h/H/g' >> hello.sed
$ echo 's/w/W/g' >> hello.sed
$ echo "hello world" | sed -f hello.sed
Hello World

    Use -f to execute sed script file

    ###Examples

    sh
    $ sed 's/old/new/g' file.txt
$ sed 's/old/new/g' file.txt > new.txt
$ sed 's/old/new/g' -i file.txt
$ sed 's/old/new/g' -i.backup file.txt

    ##Sed commands

    ###Commands

    Command Example Description
    p sed -n ‘1,4 p’ input.txt Print lines 1-4
    p sed -n -e ‘1,4 p’ -e ‘6,7 p’ input.txt Print lines 1-4 and 6-7
    d sed ‘1,4 d’ input.txt Print lines except 1-4
    w sed -n ‘1,4 w output.txt’ input.txt Write pattern space to file
    a sed ‘2 a new-line’ input.txt Append line after
    i sed ‘2 i new-line’ input.txt Insert line before

    ###Space commands

    Command Description
    n Print pattern space, empty pattern space, and read next line
    x Swap pattern space with hold space
    h Copy pattern space to hold space
    H Append pattern space to hold space
    g Copy hold space to pattern space
    G Append hold space to pattern space

    ###Flags

    sh
    $ sed 's/old/new/[flags]' [input-file]
    Flag Description
    g Global substitution
    1,2... Substitute the nth occurrence
    p Print only the substituted line
    w Write only the substituted line to a file
    I Ignore case while searching
    e Substitute and execute in the command line

    ###Loops commands

    Command Description
    b label Branch to a label (for looping)
    t label Branch to a label only on successful substitution
    (for looping)
    :label Label for the b and t commands (for looping)
    N Append next line to pattern space
    P Print 1st line in multi-line
    D Delete 1st line in multi-line

    ###Misc Flags

    Flag Description
    / | ^ @ ! # Substitution delimiter can be any character
    & Gets the matched pattern
    ( ) \1 \2 \3 Group using ( and ).
    Use \1, \2 in replacement to refer the group

    ##Sed examples

    ###Replacing text

    Replace all occurrences of a string

    sh
    $ sed 's/old/new/g' file.txt

    Replace only the nth occurrence of a string

    sh
    $ sed 's/old/new/2' file.txt

    Replace a string only on the 5th line

    sh
    $ sed '5 s/old/new/' file.txt

    Replace “world” with “universe” but only if the line begins with “hello”

    sh
    $ sed '/hello/s/world/universe/' file.txt

    Remove “" from the end of each line

    sh
    $ sed 's/\\$//' file.txt

    Remove all whitespace from beginning of each line

    sh
    $ sed 's/^\s*//' file.txt

    Remove comments. Even those that are at the end of a line

    sh
    $ sed 's/#.*$//' file.txt

    ###Search for text

    Search for a string and only print the lines that were matched

    sh
    $ sed -n '/hello/p' file.txt

    Case insensitive search

    sh
    $ sed -n '/hello/Ip' file.txt

    Search for a string but only output lines that do not match

    sh
    $ sed -n '/hello/!p' file.txt

    ###Appending lines

    Append line after line 2

    sh
    $ sed '2a Text after line 2' file.txt

    Append line at the end of the file

    sh
    $ sed '$a THE END!' file.txt

    Append line after every 3rd line starting from line 3

    sh
    $ sed '3~3a Some text' file.txt

    ###Numbering

    Number line of a file (simple left alignment)

    sh
    $ sed = file.txt | sed 'N;s/\n/\t/'

    Number line of a file (number on left, right-aligned)

    sh
    $ sed = file.txt | sed 'N; s/^/   /; s/ *\(.\{6,\}\)\n/\1  /'

    Number line of file, but only print numbers if line is not blank

    sh
    $ sed '/./=' file.txt | sed '/./N; s/\n/ /'

    Count lines (emulates “wc -l”)

    sh
    $ sed -n '$='

    ###Prepending lines

    Insert text before line 5

    sh
    $ sed '5i line number five' file.txt

    Insert “Example: " before each line that contains “hello”

    sh
    $ sed '/hello/i Example: ' file.txt

    ###Deleting lines

    Delete line 5-7 in file

    sh
    $ sed '5,7d' file.txt

    Delete every 2nd line starting with line 3

    sh
    $ sed '3~2d' file.txt

    Delete the last line in file

    sh
    $ sed '$d' file.txt

    Delete lines starting with “Hello”

    sh
    $ sed '/^Hello/d' file.txt

    Delete all empty lines

    sh
    $ sed '/^$/d' file.txt

    Delete lines starting with “#”

    sh
    $ sed '/^#/d' file.txt

    ###File spacing

    Double space

    sh
    $ sed G

    Delete all blank lines and double space

    sh
    $ sed '/^$/d;G'

    Triple space a file

    sh
    $ sed 'G;G'

    Undo double-spacing

    sh
    $ sed 'n;d'

    Insert a blank line above line which matches “regex”

    sh
    $ sed '/regex/{x;p;x;}'

    Insert a blank line below line which matches “regex”

    sh
    $ sed '/regex/G'

    Insert a blank line around line which matches “regex”

    sh
    $ sed '/regex/{x;p;x;G;}'

    ##Also see

    ###Replacing text

    Replace all occurrences of a string

    TEXT
    $ sed 's/old/new/g' file.txt

    Replace only the nth occurrence of a string

    TEXT
    $ sed 's/old/new/2' file.txt

    Replace replace a string only on the 5th line

    TEXT
    $ sed '5 s/old/new/' file.txt

    Replace “world” with “universe” but only if the line begins with “hello”

    TEXT
    $ sed '/hello/s/world/universe/' file.txt

    Remove "” from the end of each line

    TEXT
    $ sed 's/\\$//' file.txt

    Remove all whitespace from beginning of each line

    TEXT
    $ sed 's/^\s*//' file.txt

    Remove comments. Even those that are at the end of a line

    TEXT
    $ sed 's/#.*$//' file.txt

    ###Search for text

    Search for a string and only print the lines that were matched

    TEXT
    $ sed -n '/hello/p' file.txt

    Case insensitive search

    TEXT
    $ sed -n '/hello/Ip' file.txt

    Search for a string but only output lines that do not match

    TEXT
    $ sed -n '/hello/!p' file.txt

    ###Appending lines

    Append line after line 2

    TEXT
    $ sed '2a Text after line 2' file.txt

    Append line at the end of the file

    TEXT
    $ sed '$a THE END!' file.txt

    Append line after every 3rd line starting from line 3

    TEXT
    $ sed '3~3a Some text' file.txt

    ###Numbering

    Number line of a file (simple left alignment)

    TEXT
    $ sed = file.txt | sed 'N;s/\n/\t/'

    Number line of a file (number on left, right-aligned)

    TEXT
    $ sed = file.txt | sed 'N; s/^/   /; s/ *\(.\{6,\}\)\n/\1  /'

    Number line of file, but only print numbers if line is not blank

    TEXT
    $ sed '/./=' file.txt | sed '/./N; s/\n/ /'

    Count lines (emulates “wc -l”)

    TEXT
    $ sed -n '$='

    ###Prepending lines

    Insert text before line 5

    TEXT
    $ sed '5i line number five' file.txt

    Insert “Example:” before each line that contains “hello”

    TEXT
    $ sed '/hello/i Example: ' file.txt

    ###Deleting lines

    Delete line 5-7 in file

    TEXT
    $ sed '5,7d' file.txt

    Delete every 2nd line starting with line 3

    TEXT
    $ sed '3~2d' file.txt

    Delete the last line in file

    TEXT
    $ sed '$d' file.txt

    Delete lines starting with “Hello”

    TEXT
    $ sed '/^Hello/d' file.txt

    Delete all empty lines

    TEXT
    $ sed '/^$/d' file.txt

    Delete lines starting with “#”

    TEXT
    $ sed '/^#/d' file.txt

    ###File spacing

    Double space

    TEXT
    $ sed G

    Delete all blank lines and double space

    TEXT
    $ sed '/^$/d;G'

    Triple space a file

    TEXT
    $ sed 'G;G'

    Undo double-spacing

    TEXT
    $ sed 'n;d'

    Insert a blank line above line which matches “regex”

    TEXT
    $ sed '/regex/{x;p;x;}'

    Insert a blank line below line which matches “regex”

    TEXT
    $ sed '/regex/G'

    Insert a blank line around line which matches “regex”

    TEXT
    $ sed '/regex/{x;p;x;G;}'