Différences

Ci-dessous, les différences entre deux révisions de la page.

--- tech:bash_astuces [2025/09/11 11:19] – Jean-Baptiste
+++ tech:bash_astuces [2026/06/16 15:23] (Version actuelle) – Jean-Baptiste
@@ Ligne 1: / Ligne 1: @@
+<!DOCTYPE markdown>
+{{tag>Brouillon bash }}
+# Bash astuces
+Voir :
+* [15 Linux Bash History Expansion Examples You Should Know](http://www.thegeekstuff.com/2011/08/bash-history-expansion/)
+* https://scalastic.io/bash-functional-programming/
+## Check syntax avec shellcheck
+Voir aussi :
+* https://github.com/oxsecurity/megalinter
+~~~bash
+shellcheck monscript.sh
+~~~
+Si faux positif
+~~~bash
+# shellcheck disable=SC2086
+rsync $RSYNC_OPT "${PART}/" "${PART_TMP}/"
+~~~
+~~~bash
+$ shellcheck plop.sh
+In mkiso-debian.sh line 56:
+        source "$FIC_PROPERTIES"
+        ^-- SC1090: Can't follow non-constant source. Use a directive to specify location.
+~~~
+Solution
+Ajouter en commentaire `shellcheck source=`
+`plop.sh`
+~~~bash
+# shellcheck source=vars/vm-deb10.var
+source "$FIC_PROPERTIES"
+~~~
+puis
+~~~bash
+shellcheck -x plop.sh
+~~~
+`.shellcheckrc`
+~~~bash
+external-sources=true
+shell=bash
+color=always
+~~~
+## Variables
+Alternative à **eval** pour les variables
+Meta variables
+~~~
+$ a=1
+$ b=2
+$ meta_var="a"
+$ echo ${!meta_var}
+~~~
+Appel de variable
+~~~
+$ B=2
+$ KEY=B
+$ echo ${KEY}
+B
+$ echo ${!KEY}
+~~~
+Déclaration / affectation de variables dynamiques
+~~~
+$ declare $KEY=12
+$ echo ${!KEY}
+~~~
+Ou encore
+~~~bash
+K=V
+declare -n V2=K
+# Ce qui revient à :
+# V2="$K"
+$ LETTRE=ALPHA
+$ ALPHA=A
+$ declare -n PLOP=$LETTRE
+$ echo $PLOP
+A
+~~~
+### Linter
+shfmt
+https://github.com/mvdan/sh
+~~~bash
+~/go/bin/shfmt -i 4 -s -w plop.sh
+~~~
+Auto indent
+vim
+~~~
+:set expandtab ts=4 sw=4 ai
+:retab
+~~~
+bashate
+~~~bash
+pip3 install bashate
+bashate file.sh
+bashate -i E010,E011 file.sh file2.sh
+~~~
+### Autres
+`/etc/skel/.bash_logout`
+~~~bash
+/usr/bin/clear
+~~~