From 1a1c50cc01a5a91013b86708dc2a8e5ad330619e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Helleu?= <flashcode@flashtux.org>
Date: Fri, 27 Jun 2014 07:54:53 +0200
Subject: [PATCH] core: add option "env" in command /set

---
 ChangeLog.asciidoc                            |   1 +
 .../autogen/plugin_api/completions.asciidoc   |   4 +
 doc/de/autogen/user/weechat_commands.asciidoc |  40 +++---
 doc/de/weechat_faq.de.asciidoc                |  25 ++--
 doc/de/weechat_user.de.asciidoc               |   8 +-
 .../autogen/plugin_api/completions.asciidoc   |   4 +
 doc/en/autogen/user/weechat_commands.asciidoc |  26 ++--
 doc/en/weechat_faq.en.asciidoc                |  18 ++-
 doc/en/weechat_user.en.asciidoc               |   4 +-
 .../autogen/plugin_api/completions.asciidoc   |   4 +
 doc/fr/autogen/user/weechat_commands.asciidoc |  26 ++--
 doc/fr/weechat_faq.fr.asciidoc                |  19 +--
 doc/fr/weechat_user.fr.asciidoc               |   5 +-
 .../autogen/plugin_api/completions.asciidoc   |   4 +
 doc/it/autogen/user/weechat_commands.asciidoc |  30 ++--
 doc/it/weechat_faq.it.asciidoc                |  23 +--
 doc/it/weechat_user.it.asciidoc               |   7 +-
 .../autogen/plugin_api/completions.asciidoc   |   4 +
 doc/ja/autogen/user/weechat_commands.asciidoc |  40 +++---
 doc/ja/weechat_faq.ja.asciidoc                |  23 +--
 doc/ja/weechat_user.ja.asciidoc               |   7 +-
 .../autogen/plugin_api/completions.asciidoc   |   4 +
 doc/pl/autogen/user/weechat_commands.asciidoc |  30 ++--
 doc/pl/weechat_faq.pl.asciidoc                |  23 +--
 doc/pl/weechat_user.pl.asciidoc               |   7 +-
 po/cs.po                                      |  66 +++++++--
 po/de.po                                      |  68 +++++++--
 po/es.po                                      |  67 +++++++--
 po/fr.po                                      | 103 ++++++++++----
 po/hu.po                                      |  66 +++++++--
 po/it.po                                      |  67 +++++++--
 po/ja.po                                      |  68 +++++++--
 po/pl.po                                      |  67 +++++++--
 po/pt_BR.po                                   |  67 +++++++--
 po/ru.po                                      |  66 +++++++--
 po/tr.po                                      |  65 +++++++--
 po/weechat.pot                                |  59 ++++++--
 src/core/wee-command.c                        | 134 ++++++++++++++++--
 src/core/wee-completion.c                     |  81 +++++++++++
 39 files changed, 1077 insertions(+), 353 deletions(-)

diff --git a/ChangeLog.asciidoc b/ChangeLog.asciidoc
index f643798a8..8dbc2edb7 100644
--- a/ChangeLog.asciidoc
+++ b/ChangeLog.asciidoc
@@ -15,6 +15,7 @@ http://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 
 == Version 1.0 (under dev)
 
+* core: add option "env" in command /set (manage environment variables)
 * core: fix potential memory leak with infolists not freed in plugins
   (debian #751108)
 * core: fix color display of last color number + 1 (closes #101)
diff --git a/doc/de/autogen/plugin_api/completions.asciidoc b/doc/de/autogen/plugin_api/completions.asciidoc
index 9f832ab24..52e997078 100644
--- a/doc/de/autogen/plugin_api/completions.asciidoc
+++ b/doc/de/autogen/plugin_api/completions.asciidoc
@@ -114,6 +114,10 @@
 
 | weechat | cursor_areas | Bereiche in denen der Cursor frei bewegt werden kann ("chat" oder Name einer Bar)
 
+| weechat | env_value | value of an environment variable
+
+| weechat | env_vars | environment variables
+
 | weechat | filename | Dateinamen
 
 | weechat | filters_names | Liste der Filter
diff --git a/doc/de/autogen/user/weechat_commands.asciidoc b/doc/de/autogen/user/weechat_commands.asciidoc
index 8c05dc214..5995b34e9 100644
--- a/doc/de/autogen/user/weechat_commands.asciidoc
+++ b/doc/de/autogen/user/weechat_commands.asciidoc
@@ -755,33 +755,39 @@ Beispiele:
 ----
 
 [[command_weechat_set]]
-[command]*`set`* Konfigurationsparameter setzen::
+[command]*`set`* set config options and environment variables::
 
 ----
 /set  [<option> [<value>]]
       diff [<option> [<option>...]]
+      env [<variable> [<value>]]
 
-option: Name der zu ändernden Option (um mehrere Optionen anzuzeigen, kann der Platzhalter "*" verwendet werden)
- value: neuer Wert, den die Option erhalten soll
-  diff: es werden nur Optionen angezeigt, die geändert wurden
+option: name of an option (wildcard "*" is allowed)
+ value: new value for option, according to type:
+          boolean: on, off or toggle
+          integer: number, ++number or --number
+           string: any string ("" for empty string)
+            color: color name, ++number or --number
+        Note: for all types, you can use null to remove option         value (undefined value). This works only for some special         plugin variables.
+  diff: display only changed options
+   env: display or set an environment variable (use value "" to unset a variable)
 
-Abhängig von der ausgewählten Option, kann die Variable folgenden Inhalt haben:
-  boolean: on, off oder toggle
-  integer: Anzahl, ++Anzahl oder --Anzahl
-  string : jede Zeichenkette ("" für eine leere Zeichenkette)
-  color  : Name einer Farbe, ++Anzahl oder --Anzahl
-
-Für alle Typen von Variablen kann die Zeichenkette "null" (ohne "")  genutzt werden, um den Wert der Option zu löschen (undefinierter Wert). Dies kann nur auf einige besondere Variablen (Erweiterungen) angewendet werden.
-
-Beispiele:
-  Zeigt alle Optionen an, die etwas mit highlight zu tun haben:
+Examples:
+  display options about highlight:
     /set *highlight*
-  Fügt ein highlight-Wort hinzu:
+  add a word to highlight:
     /set weechat.look.highlight "word"
-  zeigt geänderte Optionen an:
+  display changed options:
     /set diff
-  zeigt geänderte Optionen, der IRC Erweiterung, an:
+  display changed options in irc plugin:
     /set diff irc.*
+  display value of environment variable LANG:
+    /set env LANG
+  set environment variable LANG and use it:
+    /set env LANG fr_FR.UTF-8
+    /upgrade
+  unset environment variable ABC:
+    /set env ABC ""
 ----
 
 [[command_weechat_unset]]
diff --git a/doc/de/weechat_faq.de.asciidoc b/doc/de/weechat_faq.de.asciidoc
index 2297f3ddf..8665c549e 100644
--- a/doc/de/weechat_faq.de.asciidoc
+++ b/doc/de/weechat_faq.de.asciidoc
@@ -277,17 +277,22 @@ Eine weitere Möglichkeit ist, ein Skript zu nutzen:
 [[change_locale_without_quit]]
 === Ich möchte die Meldungen von Weechat in einer anderen Sprache ausgeben lassen, ohne WeeChat zu beenden. Ist dies möglich?
 
-Ja, dazu kannst Du das Python-Skript 'shell.py' verwenden (erhältlich auf der
-Internetseite). Nach dem Laden des Skripts führe folgende Befehle aus:
+// TRANSLATION MISSING
+Yes, with WeeChat ≥ 1.0:
 
 ----
-/shell setenv LANG=de_DE.UTF-8
+/set env LANG de_DE.UTF-8
 /upgrade
 ----
 
-Hierdurch erhält man für das Terminal deutsche, UTF-8 kodierte Meldungen.
-Benutzer von ISO-Kodierungen können folgendes eingeben:
-`/shell setenv LANG=de_DE`.
+// TRANSLATION MISSING
+With older WeeChat:
+
+----
+/script install shell.py
+/shell setenv LANG=de_DE.UTF-8
+/upgrade
+----
 
 [[use_256_colors]]
 === Wie kann ich 256 Farben in WeeChat nutzen?
@@ -311,12 +316,12 @@ Sollte screen genutzt werden, fügt man folgende Zeile an das Ende der Datei
 term screen-256color
 ----
 
-Enthält die 'TERM'-Umgebungsvariable einen falschen Wert und WeeChat wird bereits
-ausgeführt, keine Panik! Mit dem Skript 'shell.py' kann eine Änderung der
-Umgebungsvariable durchgeführt werden, ohne das WeeChat neu gestartet werden muss:
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands (with WeeChat ≥ 1.0):
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/de/weechat_user.de.asciidoc b/doc/de/weechat_user.de.asciidoc
index 7323322e1..badc85614 100644
--- a/doc/de/weechat_user.de.asciidoc
+++ b/doc/de/weechat_user.de.asciidoc
@@ -1462,12 +1462,12 @@ Sollte screen genutzt werden, fügt man folgende Zeile an das Ende der Datei
 term screen-256color
 ----
 
-Enthält die 'TERM'-Umgebungsvariable einen falschen Wert und WeeChat wird bereits
-ausgeführt, keine Panik! Mittels dem Skript 'shell.py' kann eine Änderung der
-Umgebungsvariable durchgeführt werden, ohne das WeeChat neu gestartet werden muss:
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands:
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/en/autogen/plugin_api/completions.asciidoc b/doc/en/autogen/plugin_api/completions.asciidoc
index f5edac824..a841c5e0d 100644
--- a/doc/en/autogen/plugin_api/completions.asciidoc
+++ b/doc/en/autogen/plugin_api/completions.asciidoc
@@ -114,6 +114,10 @@
 
 | weechat | cursor_areas | areas ("chat" or bar name) for free cursor movement
 
+| weechat | env_value | value of an environment variable
+
+| weechat | env_vars | environment variables
+
 | weechat | filename | filename
 
 | weechat | filters_names | names of filters
diff --git a/doc/en/autogen/user/weechat_commands.asciidoc b/doc/en/autogen/user/weechat_commands.asciidoc
index 2d230f991..f0aff8e79 100644
--- a/doc/en/autogen/user/weechat_commands.asciidoc
+++ b/doc/en/autogen/user/weechat_commands.asciidoc
@@ -755,23 +755,22 @@ Examples:
 ----
 
 [[command_weechat_set]]
-[command]*`set`* set config options::
+[command]*`set`* set config options and environment variables::
 
 ----
 /set  [<option> [<value>]]
       diff [<option> [<option>...]]
+      env [<variable> [<value>]]
 
 option: name of an option (wildcard "*" is allowed)
- value: new value for option
+ value: new value for option, according to type:
+          boolean: on, off or toggle
+          integer: number, ++number or --number
+           string: any string ("" for empty string)
+            color: color name, ++number or --number
+        Note: for all types, you can use null to remove option         value (undefined value). This works only for some special         plugin variables.
   diff: display only changed options
-
-New value can be, according to variable type:
-  boolean: on, off or toggle
-  integer: number, ++number or --number
-   string: any string ("" for empty string)
-    color: color name, ++number or --number
-
-For all types, you can use null to remove option value (undefined value). This works only for some special plugin variables.
+   env: display or set an environment variable (use value "" to unset a variable)
 
 Examples:
   display options about highlight:
@@ -782,6 +781,13 @@ Examples:
     /set diff
   display changed options in irc plugin:
     /set diff irc.*
+  display value of environment variable LANG:
+    /set env LANG
+  set environment variable LANG and use it:
+    /set env LANG fr_FR.UTF-8
+    /upgrade
+  unset environment variable ABC:
+    /set env ABC ""
 ----
 
 [[command_weechat_unset]]
diff --git a/doc/en/weechat_faq.en.asciidoc b/doc/en/weechat_faq.en.asciidoc
index 7d6b48e71..beb83a355 100644
--- a/doc/en/weechat_faq.en.asciidoc
+++ b/doc/en/weechat_faq.en.asciidoc
@@ -264,16 +264,20 @@ Other solution is to use a script:
 [[change_locale_without_quit]]
 === I want to change the language used by WeeChat for messages, but without exiting WeeChat, is it possible?
 
-Yes, you have to use a python script, 'shell.py' (available on WeeChat website)
-and issue these commands when script is loaded:
+Yes, with WeeChat ≥ 1.0:
 
 ----
-/shell setenv LANG=en_US.UTF-8
+/set env LANG en_US.UTF-8
 /upgrade
 ----
 
-To have English messages with UTF-8 encoding for terminal, for ISO users, you
-can issue: `/shell setenv LANG=en_US`.
+With older WeeChat:
+
+----
+/script install shell.py
+/shell setenv LANG=en_US.UTF-8
+/upgrade
+----
 
 [[use_256_colors]]
 === How can I use 256 colors in WeeChat?
@@ -297,10 +301,10 @@ term screen-256color
 ----
 
 If your 'TERM' variable has wrong value and that WeeChat is already running,
-don't panic! You can change it without restarting, thanks to script 'shell.py':
+you can change it with these two commands (with WeeChat ≥ 1.0):
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/en/weechat_user.en.asciidoc b/doc/en/weechat_user.en.asciidoc
index 00bd52e78..84e9194fd 100644
--- a/doc/en/weechat_user.en.asciidoc
+++ b/doc/en/weechat_user.en.asciidoc
@@ -1441,10 +1441,10 @@ term screen-256color
 ----
 
 If your 'TERM' variable has wrong value and that WeeChat is already running,
-don't panic! You can change it without restarting, thanks to script 'shell.py':
+you can change it with these two commands:
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/fr/autogen/plugin_api/completions.asciidoc b/doc/fr/autogen/plugin_api/completions.asciidoc
index 189002fd9..08bf53b15 100644
--- a/doc/fr/autogen/plugin_api/completions.asciidoc
+++ b/doc/fr/autogen/plugin_api/completions.asciidoc
@@ -114,6 +114,10 @@
 
 | weechat | cursor_areas | zones ("chat" ou un nom de barre) pour le mouvement libre du curseur
 
+| weechat | env_value | valeur d'une variable d'environnement
+
+| weechat | env_vars | variables d'environnement
+
 | weechat | filename | nom de fichier
 
 | weechat | filters_names | noms des filtres
diff --git a/doc/fr/autogen/user/weechat_commands.asciidoc b/doc/fr/autogen/user/weechat_commands.asciidoc
index 81d1a14ab..2f4f31ec9 100644
--- a/doc/fr/autogen/user/weechat_commands.asciidoc
+++ b/doc/fr/autogen/user/weechat_commands.asciidoc
@@ -755,23 +755,22 @@ Exemples :
 ----
 
 [[command_weechat_set]]
-[command]*`set`* modifier des options de configuration::
+[command]*`set`* définir des options de configuration et des variables d'environnement::
 
 ----
 /set  [<option> [<valeur>]]
       diff [<option> [<option>...]]
+      env [<variable> [<valeur>]]
 
 option : nom d'une option (le caractère joker "*" est autorisé)
-valeur : nouvelle valeur pour l'option
+valeur : nouvelle valeur pour l'option, selon le type :
+           booléen : on, off ou toggle
+            entier : nombre, ++nombre ou --nombre
+            chaîne : toute chaîne ("" pour une chaîne vide)
+           couleur : nom de couleur, ++nombre ou --nombre
+         Note : pour tous les types, vous pouvez utiliser null pour supprimer la valeur de l'option (valeur non définie). Cela ne fonctionne qu'avec certaines options spéciales des extensions.
   diff : afficher seulement les options modifiées
-
-La nouvelle valeur peut être, selon le type de l'option :
-  booléen : on, off ou toggle
-   entier : nombre, ++nombre ou --nombre
-   chaîne : toute chaîne ("" pour une chaîne vide)
-  couleur : nom de couleur, ++nombre ou --nombre
-
-Pour tous les types, vous pouvez utiliser null pour supprimer la valeur de l'option (valeur non définie). Cela ne fonctionne qu'avec certaines options spéciales des extensions.
+   env : afficher ou définir une variable d'environnement (utilisez la valeur "" pour supprimer une variable)
 
 Exemples :
   afficher les options à propos du highlight :
@@ -782,6 +781,13 @@ Exemples :
     /set diff
   afficher les options modifiées dans l'extension irc :
     /set diff irc.*
+  afficher la valeur de la variable d'environnement LANG :
+    /set env LANG
+  modifier la variable d'environnement LANG et l'utiliser :
+    /set env LANG=fr_FR.UTF-8
+    /upgrade
+  réinitialiser la variable d'environnement ABC :
+    /set env ABC ""
 ----
 
 [[command_weechat_unset]]
diff --git a/doc/fr/weechat_faq.fr.asciidoc b/doc/fr/weechat_faq.fr.asciidoc
index 193e6266b..ff6f578b4 100644
--- a/doc/fr/weechat_faq.fr.asciidoc
+++ b/doc/fr/weechat_faq.fr.asciidoc
@@ -274,16 +274,20 @@ Une autre solution est d'utiliser un script :
 [[change_locale_without_quit]]
 === Je souhaite changer la langue des messages affichés par WeeChat, mais sans quitter WeeChat, est-ce possible ?
 
-Oui, il faut utiliser le script python 'shell.py' (disponible sur le site de
-WeeChat) et taper ces commandes une fois le script chargé :
+Oui, avec WeeChat ≥ 1.0 :
 
 ----
-/shell setenv LANG=fr_FR.UTF-8
+/set env LANG fr_FR.UTF-8
 /upgrade
 ----
 
-Pour avoir des messages anglais avec encodage UTF-8 pour le terminal, pour les
-utilisateurs en ISO, vous pouvez taper : `/shell setenv LANG=fr_FR`.
+Avec un ancien WeeChat :
+
+----
+/script install shell.py
+/shell setenv LANG=fr_FR.UTF-8
+/upgrade
+----
 
 [[use_256_colors]]
 === Comment puis-je utiliser 256 couleurs sous WeeChat ?
@@ -307,11 +311,10 @@ term screen-256color
 ----
 
 Si votre variable 'TERM' a une valeur erronée et que WeeChat est déjà lancé,
-ne paniquez pas ! Vous pouvez la changer sans redémarrer, grâce au script
-'shell.py' :
+vous pouvez la changer avec ces deux commandes (avec WeeChat ≥ 1.0) :
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/fr/weechat_user.fr.asciidoc b/doc/fr/weechat_user.fr.asciidoc
index ae18a616f..88bd35448 100644
--- a/doc/fr/weechat_user.fr.asciidoc
+++ b/doc/fr/weechat_user.fr.asciidoc
@@ -1482,11 +1482,10 @@ term screen-256color
 ----
 
 Si votre variable 'TERM' a une valeur erronée et que WeeChat est déjà lancé,
-ne paniquez pas ! Vous pouvez la changer sans redémarrer, grâce au script
-'shell.py' :
+vous pouvez la changer avec ces deux commandes :
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/it/autogen/plugin_api/completions.asciidoc b/doc/it/autogen/plugin_api/completions.asciidoc
index 4d8186a31..1921b0889 100644
--- a/doc/it/autogen/plugin_api/completions.asciidoc
+++ b/doc/it/autogen/plugin_api/completions.asciidoc
@@ -114,6 +114,10 @@
 
 | weechat | cursor_areas | aree ("chat" o nome barra) per il movimento libero del cursore
 
+| weechat | env_value | value of an environment variable
+
+| weechat | env_vars | environment variables
+
 | weechat | filename | nome file
 
 | weechat | filters_names | nomi dei filtri
diff --git a/doc/it/autogen/user/weechat_commands.asciidoc b/doc/it/autogen/user/weechat_commands.asciidoc
index 21a6b1d60..5bff01774 100644
--- a/doc/it/autogen/user/weechat_commands.asciidoc
+++ b/doc/it/autogen/user/weechat_commands.asciidoc
@@ -755,23 +755,22 @@ Examples:
 ----
 
 [[command_weechat_set]]
-[command]*`set`* imposta le opzioni di configurazione::
+[command]*`set`* set config options and environment variables::
 
 ----
-/set  [<opzione> [<valore>]]
-      diff [<opzione> [<opzione>...]]
+/set  [<option> [<value>]]
+      diff [<option> [<option>...]]
+      env [<variable> [<value>]]
 
 option: name of an option (wildcard "*" is allowed)
- value: new value for option
+ value: new value for option, according to type:
+          boolean: on, off or toggle
+          integer: number, ++number or --number
+           string: any string ("" for empty string)
+            color: color name, ++number or --number
+        Note: for all types, you can use null to remove option         value (undefined value). This works only for some special         plugin variables.
   diff: display only changed options
-
-New value can be, according to variable type:
-  boolean: on, off or toggle
-  integer: number, ++number or --number
-   string: any string ("" for empty string)
-    color: color name, ++number or --number
-
-For all types, you can use null to remove option value (undefined value). This works only for some special plugin variables.
+   env: display or set an environment variable (use value "" to unset a variable)
 
 Examples:
   display options about highlight:
@@ -782,6 +781,13 @@ Examples:
     /set diff
   display changed options in irc plugin:
     /set diff irc.*
+  display value of environment variable LANG:
+    /set env LANG
+  set environment variable LANG and use it:
+    /set env LANG fr_FR.UTF-8
+    /upgrade
+  unset environment variable ABC:
+    /set env ABC ""
 ----
 
 [[command_weechat_unset]]
diff --git a/doc/it/weechat_faq.it.asciidoc b/doc/it/weechat_faq.it.asciidoc
index f0e040067..19e255cc8 100644
--- a/doc/it/weechat_faq.it.asciidoc
+++ b/doc/it/weechat_faq.it.asciidoc
@@ -276,16 +276,22 @@ Una soluzione alternativa è usare uno script:
 [[change_locale_without_quit]]
 === Voglio cambiare la lingua utilizzata da WeeChat per i messaggi, ma senza uscire da WeeChat, è possibile?
 
-Sì. è necessario uno script python, 'shell.py' (disponibile sul sito di WeeChat)
-e digitare questi comandi quando viene caricato lo script:
+// TRANSLATION MISSING
+Yes, with WeeChat ≥ 1.0:
 
 ----
-/shell setenv LANG=it_IT.UTF-8
+/set env LANG it_IT.UTF-8
 /upgrade
 ----
 
-Per avere i messaggi in inglese con la codifica UTF-8 per il terminale, per gli
-utenti ISO, digitare: `/shell setenv LANG=en_US`.
+// TRANSLATION MISSING
+With older WeeChat:
+
+----
+/script install shell.py
+/shell setenv LANG=it_IT.UTF-8
+/upgrade
+----
 
 [[use_256_colors]]
 === Come posso usare 256 colori in WeeChat?
@@ -309,11 +315,12 @@ proprio '~/.screenrc':
 term screen-256color
 ----
 
-Se la variabile 'TERM' contiene un valore errato e WeeChat è già in esecuzione,
-niente panico! È possibile cambiarla senza riavviare, grazie allo script 'shell.py':
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands (with WeeChat ≥ 1.0):
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/it/weechat_user.it.asciidoc b/doc/it/weechat_user.it.asciidoc
index beec0362d..04634ba0b 100644
--- a/doc/it/weechat_user.it.asciidoc
+++ b/doc/it/weechat_user.it.asciidoc
@@ -1495,11 +1495,12 @@ proprio '~/.screenrc':
 term screen-256color
 ----
 
-Se la variabile 'TERM' contiene un valore errato e WeeChat è già in esecuzione,
-niente panico! È possibile cambiarla senza riavviare, grazie allo script 'shell.py':
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands:
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/ja/autogen/plugin_api/completions.asciidoc b/doc/ja/autogen/plugin_api/completions.asciidoc
index ed6421fd8..372aff72d 100644
--- a/doc/ja/autogen/plugin_api/completions.asciidoc
+++ b/doc/ja/autogen/plugin_api/completions.asciidoc
@@ -114,6 +114,10 @@
 
 | weechat | cursor_areas | カーソルを自由に動かせるエリア ("chat" またはバーの名前)
 
+| weechat | env_value | value of an environment variable
+
+| weechat | env_vars | environment variables
+
 | weechat | filename | ファイル名
 
 | weechat | filters_names | フィルタ名
diff --git a/doc/ja/autogen/user/weechat_commands.asciidoc b/doc/ja/autogen/user/weechat_commands.asciidoc
index 3139f558b..18bbf706c 100644
--- a/doc/ja/autogen/user/weechat_commands.asciidoc
+++ b/doc/ja/autogen/user/weechat_commands.asciidoc
@@ -755,33 +755,39 @@ ${sec.data.xxx} の形でフォーマットされた保護データは以下の
 ----
 
 [[command_weechat_set]]
-[command]*`set`* オプションの設定::
+[command]*`set`* set config options and environment variables::
 
 ----
 /set  [<option> [<value>]]
       diff [<option> [<option>...]]
+      env [<variable> [<value>]]
 
-option: オプションの名前 (ワイルドカード '*' を使うことができます)
- value: オプションに対する新しい値
-  diff: 変更されたオプションのみを表示
+option: name of an option (wildcard "*" is allowed)
+ value: new value for option, according to type:
+          boolean: on, off or toggle
+          integer: number, ++number or --number
+           string: any string ("" for empty string)
+            color: color name, ++number or --number
+        Note: for all types, you can use null to remove option         value (undefined value). This works only for some special         plugin variables.
+  diff: display only changed options
+   env: display or set an environment variable (use value "" to unset a variable)
 
-新しいオプションは以下の変数型に従います:
-  boolean: on、off、toggle
-  integer: 番号、++番号、--番号
-   string: 任意の文字列 (空文字列は "")
-    color: 色の名前、++色番号、--色番号
-
-どんな型であっても、オプションの値を削除する (未定義値にする) には null が使えます。これはいくつかの特別なプラグイン変数でのみ有効です。
-
-例:
-  ハイライトに関するオプションを表示:
+Examples:
+  display options about highlight:
     /set *highlight*
-  highlight に単語を追加:
+  add a word to highlight:
     /set weechat.look.highlight "word"
-  変更されたオプションを表示:
+  display changed options:
     /set diff
-  irc プラグインのオプションの内、変更されたオプションを表示
+  display changed options in irc plugin:
     /set diff irc.*
+  display value of environment variable LANG:
+    /set env LANG
+  set environment variable LANG and use it:
+    /set env LANG fr_FR.UTF-8
+    /upgrade
+  unset environment variable ABC:
+    /set env ABC ""
 ----
 
 [[command_weechat_unset]]
diff --git a/doc/ja/weechat_faq.ja.asciidoc b/doc/ja/weechat_faq.ja.asciidoc
index dcb7c87a1..18423a8d5 100644
--- a/doc/ja/weechat_faq.ja.asciidoc
+++ b/doc/ja/weechat_faq.ja.asciidoc
@@ -263,16 +263,22 @@ WeeChat ≥ 0.3.6 では、"eat_newline_glitch" オプションを有効化で
 [[change_locale_without_quit]]
 === WeeChat が出力するメッセージの言語を、再起動せずに変更したいです。このようなことは可能ですか。
 
-可能です。python スクリプト 'shell.py' (WeeChat ウェブサイトから入手可能) を使い、
-スクリプトを読み込んだら以下のコマンドを打ってください。
+// TRANSLATION MISSING
+Yes, with WeeChat ≥ 1.0:
 
 ----
-/shell setenv LANG=en_US.UTF-8
+/set env LANG ja_JP.UTF-8
 /upgrade
 ----
 
-UTF-8 エンコードされた英語メッセージが表示されるようになります、
-ISO ユーザは以下のようにして下さい: `/shell setenv LANG=en_US`
+// TRANSLATION MISSING
+With older WeeChat:
+
+----
+/script install shell.py
+/shell setenv LANG=ja_JP.UTF-8
+/upgrade
+----
 
 [[use_256_colors]]
 === どうすれば WeeChat で 256 色が使えますか。
@@ -295,11 +301,12 @@ screen を使っている場合は、以下の行を '~/.screenrc' に追加し
 term screen-256color
 ----
 
-'TERM' 変数の設定に間違いがあり、WeeChat が起動中の場合でも、
-慌てないでください! 'shell.py' を使えば再起動せずに環境変数を変更できます。
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands (with WeeChat ≥ 1.0):
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/ja/weechat_user.ja.asciidoc b/doc/ja/weechat_user.ja.asciidoc
index c373af340..a88d7fa0d 100644
--- a/doc/ja/weechat_user.ja.asciidoc
+++ b/doc/ja/weechat_user.ja.asciidoc
@@ -1439,11 +1439,12 @@ screen を使っている場合、'~/.screenrc' に以下の内容を追加し
 term screen-256color
 ----
 
-'TERM' 環境変数に間違った値が設定された状態で WeeChat を起動しても、あわてないでください!
-'shell.py' スクリプトを使えば WeeChat を再起動せずに環境変数の値を変更できます。
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands:
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/pl/autogen/plugin_api/completions.asciidoc b/doc/pl/autogen/plugin_api/completions.asciidoc
index a2d197699..acfba879e 100644
--- a/doc/pl/autogen/plugin_api/completions.asciidoc
+++ b/doc/pl/autogen/plugin_api/completions.asciidoc
@@ -114,6 +114,10 @@
 
 | weechat | cursor_areas | obszary ("chat" albo nazwa paska) dla wolnego przemieszczania się kursora
 
+| weechat | env_value | value of an environment variable
+
+| weechat | env_vars | environment variables
+
 | weechat | filename | nazwa pliku
 
 | weechat | filters_names | nazwy filtrów
diff --git a/doc/pl/autogen/user/weechat_commands.asciidoc b/doc/pl/autogen/user/weechat_commands.asciidoc
index fdab5daf5..71d04c8c7 100644
--- a/doc/pl/autogen/user/weechat_commands.asciidoc
+++ b/doc/pl/autogen/user/weechat_commands.asciidoc
@@ -755,23 +755,22 @@ Examples:
 ----
 
 [[command_weechat_set]]
-[command]*`set`* ustawia opcje konfiguracyjne::
+[command]*`set`* set config options and environment variables::
 
 ----
-/set  [<opcja> [<wartość>]]
-      diff [<opcja> [<opcja>...]]
+/set  [<option> [<value>]]
+      diff [<option> [<option>...]]
+      env [<variable> [<value>]]
 
 option: name of an option (wildcard "*" is allowed)
- value: new value for option
+ value: new value for option, according to type:
+          boolean: on, off or toggle
+          integer: number, ++number or --number
+           string: any string ("" for empty string)
+            color: color name, ++number or --number
+        Note: for all types, you can use null to remove option         value (undefined value). This works only for some special         plugin variables.
   diff: display only changed options
-
-New value can be, according to variable type:
-  boolean: on, off or toggle
-  integer: number, ++number or --number
-   string: any string ("" for empty string)
-    color: color name, ++number or --number
-
-For all types, you can use null to remove option value (undefined value). This works only for some special plugin variables.
+   env: display or set an environment variable (use value "" to unset a variable)
 
 Examples:
   display options about highlight:
@@ -782,6 +781,13 @@ Examples:
     /set diff
   display changed options in irc plugin:
     /set diff irc.*
+  display value of environment variable LANG:
+    /set env LANG
+  set environment variable LANG and use it:
+    /set env LANG fr_FR.UTF-8
+    /upgrade
+  unset environment variable ABC:
+    /set env ABC ""
 ----
 
 [[command_weechat_unset]]
diff --git a/doc/pl/weechat_faq.pl.asciidoc b/doc/pl/weechat_faq.pl.asciidoc
index 5ba30ffda..c19d50191 100644
--- a/doc/pl/weechat_faq.pl.asciidoc
+++ b/doc/pl/weechat_faq.pl.asciidoc
@@ -267,16 +267,22 @@ Innym rozwiązaniem jest użycie skryptu:
 [[change_locale_without_quit]]
 === Chcę zmienić język komunikatów wyświetlanych przez WeeChat, ale bez jego zamykania, czy jest to możliwe?
 
-Tak, musisz użyć pythonowego skryptu 'shell.py' (dostępny na stronie programu),
-oraz użyć tych komend po załadowaniu skryptu:
+// TRANSLATION MISSING
+Yes, with WeeChat ≥ 1.0:
 
 ----
-/shell setenv LANG=pl_PL.UTF-8
+/set env LANG pl_PL.UTF-8
 /upgrade
 ----
 
-Aby otrzymać polskie komunikaty dla kodowania UTF-8 w terminalu, osoby
-używające ISO, mogą wykonać: `/shell setenv LANG=pl_PL`.
+// TRANSLATION MISSING
+With older WeeChat:
+
+----
+/script install shell.py
+/shell setenv LANG=pl_PL.UTF-8
+/upgrade
+----
 
 [[use_256_colors]]
 === Jak mogę użyć 256 kolorów w WeeChat?
@@ -299,11 +305,12 @@ Jeśli używasz screena, możesz dodać to do swojego '~/.screenrc':
 term screen-256color
 ----
 
-Jeśli wartość zmiennej 'TERM' jest niepoprawna, oraz WeeChat został już uruchomiony
-nie należy panikować! Można to zmienić bez konieczności restartu, za pomocą skryptu 'shell.py':
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands (with WeeChat ≥ 1.0):
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/doc/pl/weechat_user.pl.asciidoc b/doc/pl/weechat_user.pl.asciidoc
index 51c100580..b5e517539 100644
--- a/doc/pl/weechat_user.pl.asciidoc
+++ b/doc/pl/weechat_user.pl.asciidoc
@@ -1452,11 +1452,12 @@ Jeśli używasz screena, możesz dodać to do swojego '~/.screenrc':
 term screen-256color
 ----
 
-Jeśli wartość zmiennej 'TERM' jest niewłaściwa, a WeeChat został już uruchomiony,
-nie panikuj! Możesz zmienić ją bez restatowania, za pomocą skryptu 'shell.py':
+// TRANSLATION MISSING
+If your 'TERM' variable has wrong value and that WeeChat is already running,
+you can change it with these two commands:
 
 ----
-/shell setenv TERM=screen-256color
+/set env TERM screen-256color
 /upgrade
 ----
 
diff --git a/po/cs.po b/po/cs.po
index ddd5fa75e..6daf944b1 100644
--- a/po/cs.po
+++ b/po/cs.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:45+0200\n"
 "Last-Translator: Jiri Golembiovsky <golemj@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -834,6 +834,22 @@ msgstr[0] "%s%d%s volba nastavení nalezena"
 msgstr[1] "%s%d%s volby nastavení nalezeny"
 msgstr[2] "%s%d%s voleb nastavení nalezeno"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "čtení - proměnná"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sChyba: selhalo nastavení volby \"%s\""
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sChyba: selhalo nastavení volby \"%s\""
+
 #, fuzzy, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2165,27 +2181,29 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
-msgstr "nastaví konfigurační možnosti"
+msgid "set config options and environment variables"
+msgstr ""
 
 #, fuzzy
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<možnost> [<hodnota>]]"
 
 #, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2195,7 +2213,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "možnost: jméno nastavení (může začínat nebo končit '*' pro výpis více "
 "nastavení)\n"
@@ -2590,6 +2615,14 @@ msgstr "jména polí"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+#, fuzzy
+msgid "environment variables"
+msgstr "čtení - proměnná"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "čtení - proměnná"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -10683,6 +10716,9 @@ msgstr "%s%s: nemohu nastavit \"neblokovaci\" volbu na soket"
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: vypršel časový limit \"%s\" pro %s"
 
+#~ msgid "set config options"
+#~ msgstr "nastaví konfigurační možnosti"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "vyhodit a zakázat přezdívku na kanálu"
diff --git a/po/de.po b/po/de.po
index 0c7287133..9e7efbd67 100644
--- a/po/de.po
+++ b/po/de.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-21 19:06+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-21 19:06+0200\n"
 "Last-Translator: Nils Görs <weechatter@arcor.de>\n"
 "Language-Team: German <weechatter@arcor.de>\n"
@@ -844,6 +844,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s Option"
 msgstr[1] "%s%d%s Optionen"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "keine Variable"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sFehler: Option \"%s\" konnte nicht gesetzt werden"
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sFehler: Option \"%s\" konnte nicht gesetzt werden"
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2517,25 +2533,29 @@ msgstr ""
 "    /alias ghost /eval /msg -server freenode nickserv ghost meinNick ${sec."
 "data.freenode}"
 
-msgid "set config options"
-msgstr "Konfigurationsparameter setzen"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<option> [<value>]] || diff [<option> [<option>...]]"
 
+#, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2545,7 +2565,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "option: Name der zu ändernden Option (um mehrere Optionen anzuzeigen, kann "
 "der Platzhalter \"*\" verwendet werden)\n"
@@ -2997,6 +3024,14 @@ msgstr "Namen der Layouts"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr "Namen der geschützten Daten (Datei sec.conf, section data)"
 
+#, fuzzy
+msgid "environment variables"
+msgstr "keine Variable"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "keine Variable"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -12041,6 +12076,9 @@ msgstr ""
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: Zeitüberschreitung für \"%s\" mit %s"
 
+#~ msgid "set config options"
+#~ msgstr "Konfigurationsparameter setzen"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "wirft jemanden aus dem Channel und verbannt ihn"
diff --git a/po/es.po b/po/es.po
index ba0dbe67c..1a38e7c75 100644
--- a/po/es.po
+++ b/po/es.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:45+0200\n"
 "Last-Translator: Elián Hanisch <lambdae2@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -835,6 +835,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s opción"
 msgstr[1] "%s%d%s opciones"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "Variables"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sError: no se pudo configurar la opción \"%s\""
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sError: no se pudo configurar la opción \"%s\""
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2277,26 +2293,29 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
-msgstr "establecer opciones de configuración"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<opción> [<valor>]] || diff [<opción> [<opción>...]]"
 
 #, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2306,7 +2325,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "opción: nombre de la opción (puede empezar o terminar con '*' para listar "
 "varias opciones)\n"
@@ -2722,6 +2748,14 @@ msgstr "nombres de barras"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+#, fuzzy
+msgid "environment variables"
+msgstr "Variables"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "Variables"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -10965,6 +10999,9 @@ msgstr "%s%s: no es posible configurar la opción \"nonblock\" para el socket"
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: tiempo de espera máximo para \"%s\" con %s"
 
+#~ msgid "set config options"
+#~ msgstr "establecer opciones de configuración"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "expulsa y veta a un apodo de un canal"
diff --git a/po/fr.po b/po/fr.po
index 01a85010c..848462aa2 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -21,8 +21,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
-"PO-Revision-Date: 2014-06-19 07:46+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
+"PO-Revision-Date: 2014-06-27 07:40+0200\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
 "Language: fr\n"
@@ -833,6 +833,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s option"
 msgstr[1] "%s%d%s options"
 
+#, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "La variable d'environnement \"%s\" n'est pas définie"
+
+#, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sErreur : impossible de définir la variable \"%s\" : %s"
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr "Variable \"%s\" réinitialisée"
+
+#, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sErreur : impossible de réinitialiser la variable \"%s\" : %s"
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2465,25 +2481,29 @@ msgstr ""
 "    /alias ghost /eval /msg -server freenode nickserv ghost pseudo ${sec."
 "data.freenode}"
 
-msgid "set config options"
-msgstr "modifier des options de configuration"
+msgid "set config options and environment variables"
+msgstr "définir des options de configuration et des variables d'environnement"
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
-msgstr "[<option> [<valeur>]] || diff [<option> [<option>...]]"
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
+msgstr ""
+"[<option> [<valeur>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<valeur>]]"
 
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2493,21 +2513,27 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "option : nom d'une option (le caractère joker \"*\" est autorisé)\n"
-"valeur : nouvelle valeur pour l'option\n"
+"valeur : nouvelle valeur pour l'option, selon le type :\n"
+"           booléen : on, off ou toggle\n"
+"            entier : nombre, ++nombre ou --nombre\n"
+"            chaîne : toute chaîne (\"\" pour une chaîne vide)\n"
+"           couleur : nom de couleur, ++nombre ou --nombre\n"
+"         Note : pour tous les types, vous pouvez utiliser null pour "
+"supprimer la valeur de l'option (valeur non définie). Cela ne fonctionne "
+"qu'avec certaines options spéciales des extensions.\n"
 "  diff : afficher seulement les options modifiées\n"
-"\n"
-"La nouvelle valeur peut être, selon le type de l'option :\n"
-"  booléen : on, off ou toggle\n"
-"   entier : nombre, ++nombre ou --nombre\n"
-"   chaîne : toute chaîne (\"\" pour une chaîne vide)\n"
-"  couleur : nom de couleur, ++nombre ou --nombre\n"
-"\n"
-"Pour tous les types, vous pouvez utiliser null pour supprimer la valeur de "
-"l'option (valeur non définie). Cela ne fonctionne qu'avec certaines options "
-"spéciales des extensions.\n"
+"   env : afficher ou définir une variable d'environnement (utilisez la "
+"valeur \"\" pour supprimer une variable)\n"
 "\n"
 "Exemples :\n"
 "  afficher les options à propos du highlight :\n"
@@ -2517,7 +2543,14 @@ msgstr ""
 "  afficher les options modifiées :\n"
 "    /set diff\n"
 "  afficher les options modifiées dans l'extension irc :\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  afficher la valeur de la variable d'environnement LANG :\n"
+"    /set env LANG\n"
+"  modifier la variable d'environnement LANG et l'utiliser :\n"
+"    /set env LANG=fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  réinitialiser la variable d'environnement ABC :\n"
+"    /set env ABC \"\""
 
 msgid "unset/reset config options"
 msgstr "supprimer/réinitialiser des options de configuration"
@@ -2929,6 +2962,12 @@ msgstr "noms des dispositions"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr "noms de données sécurisées (fichier sec.conf, section data)"
 
+msgid "environment variables"
+msgstr "variables d'environnement"
+
+msgid "value of an environment variable"
+msgstr "valeur d'une variable d'environnement"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -11794,6 +11833,12 @@ msgstr ""
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s : délai d'attente dépassé pour \"%s\" avec %s"
 
+#~ msgid "%s unset"
+#~ msgstr "%s réinitialisée"
+
+#~ msgid "set config options"
+#~ msgstr "modifier des options de configuration"
+
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "éjecter un utilisateur et le bannir d'un canal"
 
diff --git a/po/hu.po b/po/hu.po
index 597c83fad..ae65c33d4 100644
--- a/po/hu.po
+++ b/po/hu.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-04-05 16:12+0200\n"
 "Last-Translator: Andras Voroskoi <voroskoi@frugalware.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -865,6 +865,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] "megtalált opciók\n"
 msgstr[1] "megtalált opciók\n"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "  . típus: szám\n"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%s nem sikerült a modul opciókat elmenteni\n"
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%s nem sikerült a modul opciókat elmenteni\n"
+
 #, fuzzy, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -1911,26 +1927,28 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
-msgstr "konfigurációs paraméterek beállítása"
+msgid "set config options and environment variables"
+msgstr ""
 
 #, fuzzy
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[opció [ = érték]]"
 
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -1940,7 +1958,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 
 #, fuzzy
@@ -2268,6 +2293,14 @@ msgstr "Aliaszok listája:\n"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+#, fuzzy
+msgid "environment variables"
+msgstr "  . típus: szám\n"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "  . típus: szám\n"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -10071,6 +10104,9 @@ msgstr "%s DCC: nem sikerült 'nonblock' opciót beállítani a csatornán\n"
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s hiányzó argumentum a(z) \"%s\" opciónak\n"
 
+#~ msgid "set config options"
+#~ msgstr "konfigurációs paraméterek beállítása"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "kirúgja és kitiltja a felhasználót a szobából"
diff --git a/po/it.po b/po/it.po
index 95ed44e6b..2f0836583 100644
--- a/po/it.po
+++ b/po/it.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:46+0200\n"
 "Last-Translator: Esteban I. Ruiz Moreno <exio4.com@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -821,6 +821,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s opzione"
 msgstr[1] "%s%d%s opzioni"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "Variabili"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sErrore: impossibile impostare l'opzione \"%s\""
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sErrore: impossibile impostare l'opzione \"%s\""
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2362,26 +2378,29 @@ msgstr ""
 "    /alias ghost /eval /msg -server freenode nickserv ghost mionick ${sec."
 "data.freenode}"
 
-msgid "set config options"
-msgstr "imposta le opzioni di configurazione"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<opzione> [<valore>]] || diff [<opzione> [<opzione>...]]"
 
 #, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2391,7 +2410,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "opzione: nome di un'opzione (può iniziare o terminare con '*' per elencare "
 "più opzioni)\n"
@@ -2810,6 +2836,14 @@ msgstr "nomi dei layout"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr "nome dei dati sensibili (file sec.conf, sezione data)"
 
+#, fuzzy
+msgid "environment variables"
+msgstr "Variabili"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "Variabili"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -11136,6 +11170,9 @@ msgstr ""
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: timeout per \"%s\" con %s"
 
+#~ msgid "set config options"
+#~ msgstr "imposta le opzioni di configurazione"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "caccia e banna un nick da un canale"
diff --git a/po/ja.po b/po/ja.po
index df8dd9f39..213cd8ce5 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:46+0200\n"
 "Last-Translator: AYANOKOUZI, Ryuunosuke <i38w7i3@yahoo.co.jp>\n"
 "Language-Team: Japanese <https://github.com/l/weechat/tree/translation_ja>\n"
@@ -819,6 +819,22 @@ msgid "%s%d%s option"
 msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s 個のオプション"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "変数がありません"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sエラー: オプション \"%s\" の設定に失敗しました"
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sエラー: オプション \"%s\" の設定に失敗しました"
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2397,25 +2413,29 @@ msgstr ""
 "    /alias ghost /eval /msg -server freenode nickserv ghost mynick ${sec."
 "data.freenode}"
 
-msgid "set config options"
-msgstr "オプションの設定"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<option> [<value>]] || diff [<option> [<option>...]]"
 
+#, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2425,7 +2445,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "option: オプションの名前 (ワイルドカード '*' を使うことができます)\n"
 " value: オプションに対する新しい値\n"
@@ -2850,6 +2877,14 @@ msgstr "レイアウトの名前"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr "保護データの名前 (sec.conf ファイル、セクションデータ)"
 
+#, fuzzy
+msgid "environment variables"
+msgstr "変数がありません"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "変数がありません"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -11343,6 +11378,9 @@ msgstr "%s%s: ソケットにオプション \"nonblock\" を設定できませ
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: \"%s\" のタイムアウト %s"
 
+#~ msgid "set config options"
+#~ msgstr "オプションの設定"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "チャンネルからニックネームをキックして参加を禁止"
diff --git a/po/pl.po b/po/pl.po
index ce0d7777a..90e992fba 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:46+0200\n"
 "Last-Translator: Krzysztof Korościk <soltys@szluug.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -834,6 +834,22 @@ msgstr[0] "%s%d%s opcja"
 msgstr[1] "%s%d%s opcje"
 msgstr[2] "%s%d%s opcji"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "zmienne"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sBłąd: nie udało się ustawić opcji \"%s\""
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sBłąd: nie udało się ustawić opcji \"%s\""
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2437,26 +2453,29 @@ msgstr ""
 "    /alias ghost /eval /msg -server freenode nickserv ghost mójnick ${sec."
 "data.freenode}"
 
-msgid "set config options"
-msgstr "ustawia opcje konfiguracyjne"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<opcja> [<wartość>]] || diff [<opcja> [<opcja>...]]"
 
 #, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2466,7 +2485,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "opcja: nazwa opcji (może zaczynać lub kończyć się \"*\" do wyświetlania "
 "wielu opcji)\n"
@@ -2895,6 +2921,14 @@ msgstr "nazwy układów"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr "nazwy zabezpieczonych danych (plik sec.conf, sekcja data)"
 
+#, fuzzy
+msgid "environment variables"
+msgstr "zmienne"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "zmienne"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -11404,6 +11438,9 @@ msgstr "%s%s: nie można ustawić opcji \"nonblock\" dla gniazda: błąd %d %s"
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: przekroczono czas na \"%s\" z %s"
 
+#~ msgid "set config options"
+#~ msgstr "ustawia opcje konfiguracyjne"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "wykopuje i banuje użytkownika na kanale"
diff --git a/po/pt_BR.po b/po/pt_BR.po
index 6da271722..0ff708b39 100644
--- a/po/pt_BR.po
+++ b/po/pt_BR.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:46+0200\n"
 "Last-Translator: Sergio Durigan Junior <sergiosdj@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -856,6 +856,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s opção de configuração"
 msgstr[1] "%s%d%s opções de configuração"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "Variáveis"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sErro: falhou ao configurar a opção \"%s\""
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sErro: falhou ao configurar a opção \"%s\""
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -2230,26 +2246,29 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
-msgstr "define opções de configuração"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<opção> [<valor>]] || diff [<opção> [<opção>...]]"
 
 #, fuzzy
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -2259,7 +2278,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 "opção: nome de uma opção\n"
 "valor: novo valor para a opção\n"
@@ -2677,6 +2703,14 @@ msgstr "nomes das disposições"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+#, fuzzy
+msgid "environment variables"
+msgstr "Variáveis"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "Variáveis"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -10329,6 +10363,9 @@ msgstr "%s%s: não foi possível setar opção \"nonblock\" para o socket"
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s%s: tempo esgotado para \"%s\" com %s"
 
+#~ msgid "set config options"
+#~ msgstr "define opções de configuração"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "lista de apelidos para um canal IRC"
diff --git a/po/ru.po b/po/ru.po
index af9ed9edb..932cac27b 100644
--- a/po/ru.po
+++ b/po/ru.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-04-05 16:12+0200\n"
 "Last-Translator: Aleksey V Zapparov AKA ixti <ixti@member.fsf.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -885,6 +885,22 @@ msgstr[0] "параметров найдено\n"
 msgstr[1] "параметров найдено\n"
 msgstr[2] "параметров найдено\n"
 
+#, fuzzy, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr "  . тип: целочисленный\n"
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%s не могу сохранить конфигурационный файл pluginов\n"
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%s не могу сохранить конфигурационный файл pluginов\n"
+
 #, fuzzy, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -1934,26 +1950,28 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
-msgstr "настроить параметры конфигурации"
+msgid "set config options and environment variables"
+msgstr ""
 
 #, fuzzy
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[параметр [ = значение]]"
 
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -1963,7 +1981,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 
 #, fuzzy
@@ -2291,6 +2316,14 @@ msgstr "Список сокращений:\n"
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+#, fuzzy
+msgid "environment variables"
+msgstr "  . тип: целочисленный\n"
+
+#, fuzzy
+msgid "value of an environment variable"
+msgstr "  . тип: целочисленный\n"
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -10092,6 +10125,9 @@ msgstr "%s DCC: не могу установить неблокирующий р
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr "%s нет аргумента для параметра \"%s\"\n"
 
+#~ msgid "set config options"
+#~ msgstr "настроить параметры конфигурации"
+
 #, fuzzy
 #~ msgid "kick and ban a nick from a channel"
 #~ msgstr "кикает и банит пользователя с канала"
diff --git a/po/tr.po b/po/tr.po
index b118f0022..6bdbde106 100644
--- a/po/tr.po
+++ b/po/tr.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2014-06-19 07:48+0200\n"
 "Last-Translator: Hasan Kiran <sunder67@hotmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -778,6 +778,22 @@ msgid "%s%d%s option"
 msgid_plural "%s%d%s options"
 msgstr[0] "%s%d%s seçenekler"
 
+#, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr "%sHata: dosya \"%s\" oluşturulamaz"
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, fuzzy, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr "%sHata: dosya \"%s\" oluşturulamaz"
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -1730,25 +1746,28 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
-msgstr "yapılandırma seçenekleri ayarı"
+msgid "set config options and environment variables"
+msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+#, fuzzy
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr "[<seçenek> [<değer>]] || diff [<seçenek> [<seçenek>...]]"
 
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -1758,7 +1777,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 
 msgid "unset/reset config options"
@@ -2032,6 +2058,12 @@ msgstr ""
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+msgid "environment variables"
+msgstr ""
+
+msgid "value of an environment variable"
+msgstr ""
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
@@ -9096,3 +9128,6 @@ msgstr ""
 #, c-format
 msgid "%s%s: timeout for \"%s\" with %s"
 msgstr ""
+
+#~ msgid "set config options"
+#~ msgstr "yapılandırma seçenekleri ayarı"
diff --git a/po/weechat.pot b/po/weechat.pot
index 40e00469b..88077109f 100644
--- a/po/weechat.pot
+++ b/po/weechat.pot
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat 0.4.1-dev\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2014-06-19 07:44+0200\n"
+"POT-Creation-Date: 2014-06-27 07:39+0200\n"
 "PO-Revision-Date: 2013-02-14 18:20+0100\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -782,6 +782,22 @@ msgid_plural "%s%d%s options"
 msgstr[0] ""
 msgstr[1] ""
 
+#, c-format
+msgid "Environment variable \"%s\" is not defined"
+msgstr ""
+
+#, c-format
+msgid "%sError: failed to set variable \"%s\": %s"
+msgstr ""
+
+#, c-format
+msgid "Variable \"%s\" unset"
+msgstr ""
+
+#, c-format
+msgid "%sError: failed to unset variable \"%s\": %s"
+msgstr ""
+
 #, c-format
 msgid "%s%d%s option with value changed"
 msgid_plural "%s%d%s options with value changed"
@@ -1732,25 +1748,27 @@ msgid ""
 "data.freenode}"
 msgstr ""
 
-msgid "set config options"
+msgid "set config options and environment variables"
 msgstr ""
 
-msgid "[<option> [<value>]] || diff [<option> [<option>...]]"
+msgid ""
+"[<option> [<value>]] || diff [<option> [<option>...]] || env [<variable> "
+"[<value>]]"
 msgstr ""
 
 msgid ""
 "option: name of an option (wildcard \"*\" is allowed)\n"
-" value: new value for option\n"
+" value: new value for option, according to type:\n"
+"          boolean: on, off or toggle\n"
+"          integer: number, ++number or --number\n"
+"           string: any string (\"\" for empty string)\n"
+"            color: color name, ++number or --number\n"
+"        Note: for all types, you can use null to remove option         value "
+"(undefined value). This works only for some special         plugin "
+"variables.\n"
 "  diff: display only changed options\n"
-"\n"
-"New value can be, according to variable type:\n"
-"  boolean: on, off or toggle\n"
-"  integer: number, ++number or --number\n"
-"   string: any string (\"\" for empty string)\n"
-"    color: color name, ++number or --number\n"
-"\n"
-"For all types, you can use null to remove option value (undefined value). "
-"This works only for some special plugin variables.\n"
+"   env: display or set an environment variable (use value \"\" to unset a "
+"variable)\n"
 "\n"
 "Examples:\n"
 "  display options about highlight:\n"
@@ -1760,7 +1778,14 @@ msgid ""
 "  display changed options:\n"
 "    /set diff\n"
 "  display changed options in irc plugin:\n"
-"    /set diff irc.*"
+"    /set diff irc.*\n"
+"  display value of environment variable LANG:\n"
+"    /set env LANG\n"
+"  set environment variable LANG and use it:\n"
+"    /set env LANG fr_FR.UTF-8\n"
+"    /upgrade\n"
+"  unset environment variable ABC:\n"
+"    /set env ABC \"\""
 msgstr ""
 
 msgid "unset/reset config options"
@@ -2033,6 +2058,12 @@ msgstr ""
 msgid "names of secured data (file sec.conf, section data)"
 msgstr ""
 
+msgid "environment variables"
+msgstr ""
+
+msgid "value of an environment variable"
+msgstr ""
+
 msgid ""
 "Warning: option weechat.look.save_config_on_exit is disabled, so the option "
 "weechat.look.save_layout_on_exit is ignored"
diff --git a/src/core/wee-command.c b/src/core/wee-command.c
index 5daa30b9c..76f6a8e9f 100644
--- a/src/core/wee-command.c
+++ b/src/core/wee-command.c
@@ -37,6 +37,7 @@
 #include <time.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <errno.h>
 
 #include "weechat.h"
 #include "wee-command.h"
@@ -5678,13 +5679,106 @@ command_set_display_option_lists (char **argv, int arg_start, int arg_end,
 COMMAND_CALLBACK(set)
 {
     char *value;
-    int number_found, rc, display_only_changed, arg_option_start, arg_option_end;
+    const char *ptr_string;
+    int i, number_found, rc, display_only_changed, arg_option_start;
+    int arg_option_end, list_size;
     struct t_config_option *ptr_option, *ptr_option_before;
+    struct t_weelist *list;
+    struct t_weelist_item *item;
 
     /* make C compiler happy */
     (void) data;
     (void) buffer;
 
+    /* display/set environment variables */
+    if ((argc > 1) && (string_strcasecmp (argv[1], "env") == 0))
+    {
+        if (argc == 2)
+        {
+            /* display a sorted list of all environment variables */
+            list = weelist_new ();
+            if (!list)
+                return WEECHAT_RC_ERROR;
+            for (i = 0; environ[i]; i++)
+            {
+                weelist_add (list, environ[i], WEECHAT_LIST_POS_SORT, NULL);
+            }
+            list_size = weelist_size (list);
+            for (i = 0; i < list_size; i++)
+            {
+                item = weelist_get (list, i);
+                if (item)
+                {
+                    ptr_string = weelist_string (item);
+                    if (ptr_string)
+                        gui_chat_printf (NULL, "%s", ptr_string);
+                }
+            }
+            weelist_free (list);
+            return WEECHAT_RC_OK;
+        }
+
+        if (argc == 3)
+        {
+            /* display an environment variable */
+            value = getenv (argv[2]);
+            if (value)
+            {
+                gui_chat_printf (NULL, "%s=%s", argv[2], value);
+            }
+            else
+            {
+                gui_chat_printf (NULL,
+                                 _("Environment variable \"%s\" is not "
+                                   "defined"),
+                                 argv[2]);
+            }
+            return WEECHAT_RC_OK;
+        }
+
+        /* set/unset an environment variable */
+        value = string_remove_quotes (argv_eol[3], "'\"");
+        if (value && value[0])
+        {
+            /* set variable */
+            if (setenv (argv[2], value, 1) == 0)
+            {
+                gui_chat_printf (NULL, "%s=%s", argv[2], value);
+            }
+            else
+            {
+                gui_chat_printf (NULL,
+                                 _("%sError: failed to set variable "
+                                   "\"%s\": %s"),
+                                 gui_chat_prefix[GUI_CHAT_PREFIX_ERROR],
+                                 argv[2],
+                                 strerror (errno));
+            }
+        }
+        else
+        {
+            /* unset variable */
+            if (unsetenv (argv[2]) == 0)
+            {
+                gui_chat_printf (NULL,
+                                 _("Variable \"%s\" unset"),
+                                 argv[2]);
+            }
+            else
+            {
+                gui_chat_printf (NULL,
+                                 _("%sError: failed to unset variable "
+                                   "\"%s\": %s"),
+                                 gui_chat_prefix[GUI_CHAT_PREFIX_ERROR],
+                                 argv[2],
+                                 strerror (errno));
+            }
+        }
+        if (value)
+            free (value);
+        return WEECHAT_RC_OK;
+    }
+
     display_only_changed = 0;
     arg_option_start = 1;
     arg_option_end = argc - 1;
@@ -7618,20 +7712,22 @@ command_init ()
         &command_secure, NULL);
     hook_command (
         NULL, "set",
-        N_("set config options"),
-        N_("[<option> [<value>]] || diff [<option> [<option>...]]"),
+        N_("set config options and environment variables"),
+        N_("[<option> [<value>]]"
+           " || diff [<option> [<option>...]]"
+           " || env [<variable> [<value>]]"),
         N_("option: name of an option (wildcard \"*\" is allowed)\n"
-           " value: new value for option\n"
+           " value: new value for option, according to type:\n"
+           "          boolean: on, off or toggle\n"
+           "          integer: number, ++number or --number\n"
+           "           string: any string (\"\" for empty string)\n"
+           "            color: color name, ++number or --number\n"
+           "        Note: for all types, you can use null to remove option "
+           "        value (undefined value). This works only for some special "
+           "        plugin variables.\n"
            "  diff: display only changed options\n"
-           "\n"
-           "New value can be, according to variable type:\n"
-           "  boolean: on, off or toggle\n"
-           "  integer: number, ++number or --number\n"
-           "   string: any string (\"\" for empty string)\n"
-           "    color: color name, ++number or --number\n"
-           "\n"
-           "For all types, you can use null to remove option value (undefined "
-           "value). This works only for some special plugin variables.\n"
+           "   env: display or set an environment variable (use value \"\" to "
+           "unset a variable)\n"
            "\n"
            "Examples:\n"
            "  display options about highlight:\n"
@@ -7641,9 +7737,17 @@ command_init ()
            "  display changed options:\n"
            "    /set diff\n"
            "  display changed options in irc plugin:\n"
-           "    /set diff irc.*"),
+           "    /set diff irc.*\n"
+           "  display value of environment variable LANG:\n"
+           "    /set env LANG\n"
+           "  set environment variable LANG and use it:\n"
+           "    /set env LANG fr_FR.UTF-8\n"
+           "    /upgrade\n"
+           "  unset environment variable ABC:\n"
+           "    /set env ABC \"\""),
         "%(config_options) %(config_option_values)"
-        " || diff %(config_options)|%*",
+        " || diff %(config_options)|%*"
+        " || env %(env_vars) %(env_value)",
         &command_set, NULL);
     hook_command (
         NULL, "unset",
diff --git a/src/core/wee-completion.c b/src/core/wee-completion.c
index 4bb0c37be..732d3e32b 100644
--- a/src/core/wee-completion.c
+++ b/src/core/wee-completion.c
@@ -1446,6 +1446,81 @@ completion_list_add_secured_data_cb (void *data,
     return WEECHAT_RC_OK;
 }
 
+/*
+ * Adds environment variables to completion list.
+ */
+
+int
+completion_list_add_env_vars_cb (void *data,
+                                 const char *completion_item,
+                                 struct t_gui_buffer *buffer,
+                                 struct t_gui_completion *completion)
+{
+    int i;
+    char *pos, *name;
+
+    /* make C compiler happy */
+    (void) data;
+    (void) completion_item;
+    (void) buffer;
+
+    for (i = 0; environ[i]; i++)
+    {
+        pos = strchr (environ[i], '=');
+        if (pos)
+        {
+            name = string_strndup (environ[i], pos - environ[i]);
+            if (name)
+            {
+                gui_completion_list_add (completion, name,
+                                         0, WEECHAT_LIST_POS_SORT);
+                free (name);
+            }
+        }
+    }
+
+    return WEECHAT_RC_OK;
+}
+
+/*
+ * Adds value of an environment variable to completion list.
+ */
+
+int
+completion_list_add_env_value_cb (void *data,
+                                  const char *completion_item,
+                                  struct t_gui_buffer *buffer,
+                                  struct t_gui_completion *completion)
+{
+    char **argv, *value;
+    int argc;
+
+    /* make C compiler happy */
+    (void) data;
+    (void) completion_item;
+    (void) buffer;
+
+    if (completion->args)
+    {
+        argv = string_split (completion->args, " ", 0, 0, &argc);
+        if (!argv)
+            return WEECHAT_RC_OK;
+
+        if (argc > 0)
+        {
+            value = getenv (argv[argc - 1]);
+            if (value)
+            {
+                gui_completion_list_add (completion, value,
+                                         0, WEECHAT_LIST_POS_END);
+            }
+        }
+        string_free_split (argv);
+    }
+
+    return WEECHAT_RC_OK;
+}
+
 /*
  * Adds hooks for completions done by WeeChat core.
  */
@@ -1547,4 +1622,10 @@ completion_init ()
     hook_completion (NULL, "secured_data",
                      N_("names of secured data (file sec.conf, section data)"),
                      &completion_list_add_secured_data_cb, NULL);
+    hook_completion (NULL, "env_vars",
+                     N_("environment variables"),
+                     &completion_list_add_env_vars_cb, NULL);
+    hook_completion (NULL, "env_value",
+                     N_("value of an environment variable"),
+                     &completion_list_add_env_value_cb, NULL);
 }