bash_cheatsheet
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bash_cheatsheet [2014/12/07 19:30] – ginko | bash_cheatsheet [2019/02/13 16:07] (current) – [Output of a shell command] ginko | ||
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~% echo " | ~% echo " | ||
gz</ | gz</ | ||
+ | ==== Output of a shell command ==== | ||
+ | * '' | ||
+ | mytimestamp=$(date ' | ||
===== Mastering history ===== | ===== Mastering history ===== | ||
[[http:// | [[http:// | ||
Line 87: | Line 90: | ||
===== Redirection ===== | ===== Redirection ===== | ||
+ | [[http:// | ||
* Diriger plusieurs lignes vers un fichier :<code bash>/ | * Diriger plusieurs lignes vers un fichier :<code bash>/ | ||
text1 | text1 | ||
Line 93: | Line 97: | ||
text4 | text4 | ||
EOM</ | EOM</ | ||
+ | * Normal: | ||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
+ | * Append: | ||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
+ | * Pipes: | ||
+ | * '' | ||
+ | * '' | ||
+ | |||
+ | |||
+ | ==== The problem with cats ... ==== | ||
+ | |||
+ | Take a simple redirection example such as this: | ||
+ | |||
+ | '' | ||
+ | |||
+ | You've wasted a process on cat, since you could accomplish the same thing (and have it execute faster!) by doing this: | ||
+ | |||
+ | '' | ||
+ | |||
+ | ==== Sending stderr through a pipe ==== | ||
+ | |||
+ | Sending only stderr down a pipe, while having stdout still go to the screen, is an interesting trick. It can be done by passing the stdout and stderr file descriptors to temporary file descriptors, | ||
+ | |||
+ | '' | ||
===== Fonctions ===== | ===== Fonctions ===== | ||
'' | '' | ||
- | On retrouve cette syntax au coeur de la fameuse fork bomb bask '': | + | On retrouve cette syntax au coeur de la fameuse fork bomb bash '': |
bash_cheatsheet.1417977004.txt.gz · Last modified: 2014/12/07 19:30 by ginko