{"id":2706,"date":"2025-12-14T17:33:35","date_gmt":"2025-12-14T16:33:35","guid":{"rendered":"https:\/\/artheodoc.fr\/?page_id=2706"},"modified":"2025-12-14T17:33:35","modified_gmt":"2025-12-14T16:33:35","slug":"les-principales-variables-denvironnement-du-shell-bash-sous-linux","status":"publish","type":"page","link":"https:\/\/artheodoc.fr\/index.php\/les-principales-variables-denvironnement-du-shell-bash-sous-linux\/","title":{"rendered":"Les principales variables d\u2019environnement du shell Bash sous Linux"},"content":{"rendered":"\n

Variables d\u2019Environnement Essentielles dans Bash<\/h1>\n\n\n\n

Variables de Base<\/h2>\n\n\n\n
Variable<\/strong><\/th>Description<\/strong><\/th>Affichage<\/strong><\/th><\/tr><\/thead>
HOME<\/td>Chemin du r\u00e9pertoire personnel de l\u2019utilisateur.<\/td>echo $HOME : \/home\/dominique<\/code><\/td><\/tr>
USER<\/td>Nom de l\u2019utilisateur actuel.<\/td>echo $USER : dominique<\/code><\/td><\/tr>
SHELL<\/td>Chemin vers le shell utilis\u00e9 par d\u00e9faut.<\/td>echo $SHELL : \/bin\/bash<\/code><\/td><\/tr>
PWD<\/td>R\u00e9pertoire de travail actuel (Present Working Directory).<\/td>echo $PWD : \/home\/dominique<\/code><\/td><\/tr>
OLDPWD<\/td>R\u00e9pertoire de travail pr\u00e9c\u00e9dent.<\/td>echo $OLDPWD<\/td><\/tr>
PATH<\/td>Liste des r\u00e9pertoires o\u00f9 le shell recherche les ex\u00e9cutables.<\/td>echo $PATH : \/usr\/local\/sbin:\/usr\/local\/bin:\/usr\/sbin:\/usr\/bin:\/sbin:\/bin:\/usr\/games:\/usr\/local\/games:\/snap\/bin<\/code><\/td><\/tr>
LANG<\/td>Param\u00e8tres r\u00e9gionaux (langue, encodage, etc.).<\/td>echo $LANG : fr_FR.UTF-8<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

Variables de Configuration du Shell<\/h2>\n\n\n\n
Variable<\/strong><\/th>Description<\/strong><\/th>Affichage<\/strong><\/th><\/tr><\/thead>
PS1<\/td>Cha\u00eene de caract\u00e8res d\u00e9finissant le prompt principal du shell.<\/td>echo $PS1 : \\[\\e]0;\\u@\\h: \\w\\a\\]${debian_chroot:+($debian_chroot)}\\[\\033[01;32m\\]\\u@\\h\\[\\033[00m\\]:\\[\\033[01;34m\\]\\w\\[\\033[00m\\]\\$<\/code><\/td><\/tr>
PS2<\/td>Prompt secondaire (pour les commandes multi-lignes).<\/td>echo $PS2 : ><\/code><\/td><\/tr>
HISTFILE<\/td>Fichier o\u00f9 l\u2019historique des commandes est sauvegard\u00e9.<\/td>echo $HISTFILE : \/home\/dominique\/.bash_history<\/code><\/td><\/tr>
HISTSIZE<\/td>Nombre de commandes conserv\u00e9es dans l\u2019historique.<\/td>echo $HISTSIZE : 1000<\/code><\/td><\/tr>
HISTCONTROL<\/td>Contr\u00f4le quelles commandes sont enregistr\u00e9es dans l\u2019historique (ex: ignorespace).<\/td>echo $HISTCONTROL : ignoreboth<\/code><\/td><\/tr>
TERM<\/td>Type de terminal utilis\u00e9 (ex: xterm-256color).<\/td>echo $TERM : xterm-256color<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

Variables Sp\u00e9ciales du Shell Bash<\/h2>\n\n\n\n
Variable<\/strong><\/th>Description<\/strong><\/th>Exemple d’utilisation<\/strong><\/th><\/tr><\/thead>
$?<\/td>Code de retour de la derni\u00e8re commande ex\u00e9cut\u00e9e. 0 signifie succ\u00e8s, toute autre valeur indique une erreur.<\/td>echo $? apr\u00e8s une commande.<\/td><\/tr>
$$<\/td>PID (Process ID) du shell actuel.<\/td>echo $$<\/td><\/tr>
$0<\/td>Nom du script ou du shell en cours d\u2019ex\u00e9cution.<\/td>echo $0 dans un script.<\/td><\/tr>
$1, $2, …<\/td>Arguments pass\u00e9s \u00e0 un script ou une fonction.<\/td>echo $1 dans un script.<\/td><\/tr>
$#<\/td>Nombre d\u2019arguments pass\u00e9s \u00e0 un script ou une fonction.<\/td>echo $#<\/td><\/tr>
$*<\/td>ous les arguments pass\u00e9s \u00e0 un script ou une fonction, sous forme d\u2019une seule cha\u00eene.<\/td>echo $*<\/td><\/tr>
$@<\/td>Tous les arguments pass\u00e9s \u00e0 un script ou une fonction, sous forme de tableau.<\/td>for arg in \u00ab\u00a0$@\u00a0\u00bb; do echo $arg; done<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

Lister toutes les variables<\/h1>\n\n\n\n
printenv<\/pre>\n\n\n\n
ou<\/p>\n\n\n\n
env<\/pre>\n\n\n\n
\n\n\n\n
D\u00e9finir une variable<\/h1>\n\n\n\n
D\u00e9finir une variable temporaire<\/h2>\n\n\n\n
NOM_VARIABLE=\u00a0\u00bbvaleur\u00a0\u00bb<\/p>\n\n\n\n
Exemple :<\/p>\n\n\n\n
MON_VAR=\"Bonjour\"<\/pre>\n\n\n\n
D\u00e9finir une variable permanente<\/h2>\n\n\n\n
Ajoutez la ligne suivante dans ~\/.bashrc ou ~\/.bash_profile :<\/p>\n\n\n\n
export NOM_VARIABLE=\"valeur\"<\/pre>\n\n\n\n
Puis rechargez le fichier :<\/p>\n\n\n\n
source ~\/.bashrc<\/pre>\n\n\n\n
\n\n\n\n
Voir \u00e9galement<\/h1>\n\n\n\n
Modification de la variable d\u2019environnement PATH pour pouvoir utiliser les commandes du Shell<\/a><\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Variables d\u2019Environnement Essentielles dans Bash Variables de Base Variable Description Affichage HOME Chemin du r\u00e9pertoire personnel de l\u2019utilisateur. echo $HOME : \/home\/dominique USER Nom de l\u2019utilisateur actuel. echo $USER : dominique SHELL Chemin vers le shell utilis\u00e9 par d\u00e9faut. echo $SHELL : \/bin\/bash PWD R\u00e9pertoire de travail actuel (Present Working Directory). echo $PWD : \/home\/dominique OLDPWD R\u00e9pertoire de travail […]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-2706","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/pages\/2706","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/comments?post=2706"}],"version-history":[{"count":1,"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/pages\/2706\/revisions"}],"predecessor-version":[{"id":2707,"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/pages\/2706\/revisions\/2707"}],"wp:attachment":[{"href":"https:\/\/artheodoc.fr\/index.php\/wp-json\/wp\/v2\/media?parent=2706"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}