====== Linux ======

===== SED =====
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| SED Cheat sheet |{{:linux:commandes_utiles:sed_cheat_sheet.png?linkonly |}}|
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==== Syntaxe ====
<code bash>
$ sed [options] command [input-file]</code>

  * Exemples avec pipeline
<code bash>
$ cat report.txt | sed 's/Nick/John/g'
$ echo '123abc' | sed 's/[0-9]+//g'
</code>

  * commandes multiples
<code bash>
$ echo "hello world" | sed -e 's/h/H/g' -e 's/w/W/g'
Hello World
</code>

  * Script sed
<code bash>
$ echo 's/h/H/g' >> hello.sed
$ echo 's/w/W/g' >> hello.sed
$ echo "hello world" | sed -f hello.sed
Hello World
</code>
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----
==== Options ====
^Option	^Example	^Description ^
|<color #ff7f27>**-i**</color>	|''<nowiki>sed -ibak 's/On/Off/' php.ini</nowiki>''	|Backup and modify input file directly |
|<color #ff7f27>**-E**</color>	|''<nowiki>sed -E 's/[0-9]+//g' input-file</nowiki>'' |Use extended regular expressions |
|<color #ff7f27>**-n**</color>	|''<nowiki>sed -n '3 p' config.conf</nowiki>'' |Suppress default pattern space printing |
|<color #ff7f27>**-f**</color>	|''<nowiki>sed -f script.sed config.conf</nowiki>'' |Execute sed script file |
|<color #ff7f27>**-e**</color>	|''<nowiki>sed -e 'command1' -e 'command2' input-file</nowiki>'' |Execute multiple sed commands |
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----
==== Commands ====
^Command	^Example	^Description ^
|<color #22b14c>**p**</color>	|''sed -n '1,4 p' input.txt''	|Print lines 1-4 |
|<color #22b14c>**p**</color>	|''sed -n -e '1,4 p' -e '6,7 p' input.txt''	|Print lines 1-4 and 6-7 |
|<color #22b14c>**d**</color>	|''sed '1,4 d' input.txt''	|Print lines except 1-4 |
|<color #22b14c>**w**</color>	|''sed -n '1,4 w output.txt' input.txt''	|Write pattern space to file |
|<color #22b14c>**a**</color>	|''sed '2 a new-line' input.txt''	|Append line after |
|<color #22b14c>**i**</color>	|''sed '2 i new-line' input.txt''	|Insert line before |
^Space commands ^^^
|<color #22b14c>**n**</color>	| |Print pattern space, empty pattern space, and read next line |
|<color #22b14c>**x**</color>	| |Swap pattern space with hold space |
|<color #22b14c>**h**</color>	| |Copy pattern space to hold space |
|<color #22b14c>**H**</color>	| |Append pattern space to hold space |
|<color #22b14c>**g**</color>	| |Copy hold space to pattern space |
|<color #22b14c>**G**</color>	| |Append hold space to pattern space |
^Flags ^^^
| <code bash>$ sed 's/old/new/[flags]' [input-file]</code> |||
|<color #22b14c>**g**</color>	| |Global substitution |
|<color #22b14c>**1,2...**</color>	| |Substitute the nth occurrence |
|<color #22b14c>**p**</color>	| |Print only the substituted line |
|<color #22b14c>**w**</color>	| |Write only the substituted line to a file |
|<color #22b14c>**I**</color>	| |Ignore case while searching |
|<color #22b14c>**e**</color>	| |Substitute and execute in the command line |
^Loops commands ^^^
|<color #22b14c>**b label**</color>	| |Branch to a label (for looping) |
|<color #22b14c>**t label**</color>	| |Branch to a label only on successful substitution (for looping) |
|<color #22b14c>**:label**</color>	| |Label for the b and t commands (for looping) |
|<color #22b14c>**N**</color>	| |Append next line to pattern space |
|<color #22b14c>**P**</color>	| |Print 1st line in multi-line |
|<color #22b14c>**D**</color>	| |Delete 1st line in multi-line |
^Misc flags ^^^
|<color #22b14c>**/ | ^ @ ! #**</color>	| |Substitution delimiter can be any character |
|<color #22b14c>**&**</color>	| |Gets the matched pattern |
|<color #22b14c>**( ) \1 \2 \3**</color>	| |Group using ( and ). Use \1, \2 in replacement to refer the group |
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----
==== Recherche de texte ====
<code bash>
# Search for a string and only print the lines that were matched
$ sed -n '/hello/p' file.txt

# Case insensitive search
$ sed -n '/hello/Ip' file.txt

# Search for a string but only output lines that do not match
$ sed -n '/hello/!p' file.txt
</code>

==== Remplacement de texte ====
<code bash>
# Replace all occurrences of a string
$ sed 's/old/new/g' file.txt

# Replace only the nth occurrence of a string
$ sed 's/old/new/2' file.txt

# Replace replace a string only on the 5th line
$ sed '5 s/old/new/' file.txt

# Replace "world" with "universe" but only if the line begins with "hello"
$ sed '/hello/s/world/universe/' file.txt

# Remove "" from the end of each line
$ sed 's/\\$//' file.txt

# Remove all whitespace from beginning of each line
$ sed 's/^\s*//' file.txt

# Remove comments. Even those that are at the end of a line
$ sed 's/#.*$//' file.txt
</code>

==== Ajout de texte ====
<code bash>
# Append line after line 2
$ sed '2a Text after line 2' file.txt

# Append line at the end of the file
$ sed '$a THE END!' file.txt

# Append line after every 3rd line starting from line 3
$ sed '3~3a Some text' file.txt

# Insert text before line 5
$ sed '5i line number five' file.txt

# Insert "Example: " before each line that contains "hello"
$ sed '/hello/i Example: ' file.txt
</code>

==== Numérotation ====
<code bash>
# Number line of a file (simple left alignment)
$ sed = file.txt | sed 'N;s/\n/\t/'

# Number line of a file (number on left, right-aligned)
$ sed = file.txt | sed 'N; s/^/   /; s/ *\(.\{6,\}\)\n/\1  /'

# Number line of file, but only print numbers if line is not blank
$ sed '/./=' file.txt | sed '/./N; s/\n/ /'

# Count lines (emulates "wc -l")
$ sed -n '$='
</code>

==== Effacement de texte ====
<code bash>
# Delete line 5-7 in file
$ sed '5,7d' file.txt

# Delete every 2nd line starting with line 3
$ sed '3~2d' file.txt

# Delete the last line in file
$ sed '$d' file.txt

# Delete lines starting with "Hello"
$ sed '/^Hello/d' file.txt

# Delete all empty lines
$ sed '/^$/d' file.txt

# Delete lines starting with "#"
$ sed '/^#/d' file.txt
</code>

==== Gestion des espaces ====
<code bash>
# Double space
$ sed G

# Delete all blank lines and double space
$ sed '/^$/d;G'

# Triple space a file
$ sed 'G;G'

# Undo double-spacing
$ sed 'n;d'

# Insert a blank line above line which matches "regex"
$ sed '/regex/{x;p;x;}'

# Insert a blank line below line which matches "regex"
$ sed '/regex/G'

# Insert a blank line around line which matches "regex"
$ sed '/regex/{x;p;x;G;}'
</code>
==== Exemples ====
  * Liste de fichiers de moins de 30 jours, ordonnée par date dans le répertoire spécifié seulement
<code bash>
$ find ./* -prune -name "*<chaine>*" -mtime 30 | xargs -exec ls -ltr
</code>
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