core: add base 16/32/64 encoding/decoding in evaluation of expressions

27 files changed, 534 insertions, 243 deletions

diff --git a/ChangeLog.adoc b/ChangeLog.adoc
index 3124d456b..20972fff6 100644
--- a/ChangeLog.adoc
+++ b/ChangeLog.adoc
@@ -26,6 +26,7 @@ New features::
   * core: add default key kbd:[Alt+Enter] to insert a newline (issue #1498)
   * core: add flag "input_multiline" in buffer (issue #984, issue #1063)
   * core: add a scalable WeeChat logo (SVG) (issue #1454, issue #1456)
+  * core: add base 16/32/64 encoding/decoding in evaluation of expressions with "base_encode:base,xxx" and "base_decode:base,xxx"
   * core: add case sensitive wildcard matching comparison operator (`+==*+` and `+!!*+`) and case sensitive/insensitive include comparison operators (`+==-+`,  `+!!-+`, `+=-+`, `+!-+`) in evaluation of expressions
   * core: add default key kbd:[Alt+Shift+N] to toggle nicklist bar
   * core: add command line option "--stdout" in weechat-headless binary to log to stdout rather than ~/.weechat/weechat.log (issue #1475, issue #1477)
diff --git a/doc/de/includes/autogen_user_commands.de.adoc b/doc/de/includes/autogen_user_commands.de.adoc
index 97e393a2b..78e36c9b7 100644
--- a/doc/de/includes/autogen_user_commands.de.adoc
+++ b/doc/de/includes/autogen_user_commands.de.adoc
@@ -1282,75 +1282,76 @@ infolists: zeigt Information über die Infolists an
 /eval  [-n|-s] [-d] <expression>
        [-n] [-d] -c <expression1> <operator> <expression2>
 
-        -n: gibt das Ergebnis aus, ohne dass dieses in den Buffer gesendet wird (debug Modus)
-        -s: teilt Ausdrücke, bevor sie evaluiert werden (mehrere Befehle können durch Semikolon getrennt werden)
-        -d: eine Debug-Ausgabe nach Auswertung anzeigen
-        -c: Auswertung als Bedingung: nutzt Operatoren und runde Klammern, Rückgabewert als Boolean-Wert ("0" oder "1")
-expression: Ausdruck welcher verarbeitet werden soll. Variablen im Format ${variable} werden ersetzt (siehe unten); mehrere Befehle werden durch ein Semikolon voneinander getrennt
-  operator: ein logischer oder vergleichender Operand:
-            - logische Operanden:
-                &&  boolean "und"
-                ||  boolean "oder"
-            - vergleichende Operanden:
-                ==  gleich
-                !=  ungleich
-                <=  kleiner oder gleich
-                <   kleiner
-                >=  größer oder gleich
-                >   größer
-                =~  stimmt mit regulärem POSIX Ausdruck überein
-                !~  stimmt NICHT mit regulärem POSIX Ausdruck überein
-                =*  stimmt mit Maske überein (Platzhalter "*" ist erlaubt)
-                !*  stimmt mit Maske NICHT überein (Platzhalter "*" ist erlaubt)
-                =*   stimmt mit Maske überein, Groß- und Kleinschreibung wird nicht beachtet (Platzhalter "*" ist erlaubt)
-                !*   stimmt mit Maske NICHT überein, Groß- und Kleinschreibung wird nicht beachtet (Platzhalter "*" ist erlaubt)
-                ==-  ist enthalten, Groß- und Kleinschreibung wird beachtet
-                !!-  ist NICHT enthalten, Groß- und Kleinschreibung wird beachtet
-                =-   ist enthalten, Groß- und Kleinschreibung wird nicht beachtet
-                !-   ist NICHT enthalten, Groß- und Kleinschreibung wird nicht beachtet
-
-Ein Ausdruck gilt als "wahr" sofern das Ergebnis weder NULL, nicht leer und von "0" abweichend ist.
-Für einen Vergleich werden Fließkommazahlen genutzt, insofern es sich bei beiden Ausdrücken um gültige Zahlen handelt, folgende Formate werden unterstützt:
-  - Integer (Beispiele: 5, -7)
-  - Fließkommazahl (Beispiele: 5.2, -7.5, 2.83e-2)
-  - hexadezimale Zahl (Beispiele: 0xA3, -0xA3)
-Um einen Vergleich zwischen zwei Zeichenketten zu erzwingen, müssen die Ausdrücke in Anführungszeichen gesetzt werden, zum Beispiel:
+        -n: display result without sending it to buffer (debug mode)
+        -s: split expression before evaluating it (many commands can be separated by semicolons)
+        -d: display debug output after evaluation
+        -c: evaluate as condition: use operators and parentheses, return a boolean value ("0" or "1")
+expression: expression to evaluate, variables with format ${variable} are replaced (see below); many commands can be separated by semicolons
+  operator: a logical or comparison operator:
+            - logical operators:
+                &&   boolean "and"
+                ||   boolean "or"
+            - comparison operators:
+                ==   equal
+                !=   not equal
+                <=   less or equal
+                <    less
+                >=   greater or equal
+                >    greater
+                =~   is matching POSIX extended regex
+                !~   is NOT matching POSIX extended regex
+                ==*  is matching mask, case sensitive (wildcard "*" is allowed)
+                !!*  is NOT matching mask, case sensitive (wildcard "*" is allowed)
+                =*   is matching mask, case insensitive (wildcard "*" is allowed)
+                !*   is NOT matching mask, case insensitive (wildcard "*" is allowed)
+                ==-  is included, case sensitive
+                !!-  is NOT included, case sensitive
+                =-   is included, case insensitive
+                !-   is NOT included, case insensitive
+
+An expression is considered as "true" if it is not NULL, not empty, and different from "0".
+The comparison is made using floating point numbers if the two expressions are valid numbers, with one of the following formats:
+  - integer (examples: 5, -7)
+  - floating point number (examples: 5.2, -7.5, 2.83e-2)
+  - hexadecimal number (examples: 0xA3, -0xA3)
+To force a string comparison, you can add double quotes around each expression, for example:
   50 > 100      ==> 0
   "50" > "100"  ==> 1
 
-Einige Variablen werden im Ausdruck mittels der Formatierung ${variable} ersetzt. Mögliche Variablen sind, nach Reihenfolge ihrer Priorität:
-  1. eine evaluierte Teilzeichenkette (Format: "eval:xxx")
-  2. eine Zeichenkette mit Escapesequenzen (Format: "esc:xxx" oder "\xxx")
-  3. Zeichen, die in einer Zeichenkette nicht dargestellt werden sollen (Format: "hide:Zeichen,Zeichenkette")
-  4. eine Zeichenkette mit einer maximalen Anzahl an Zeichen (Format: "cut:+Max,Suffix,Zeichenkette")
-     oder maximale Anzahl an Zeichen die auf dem Bildschirm angezeigt werden sollen (Format: "cutscr:Max,Suffix,Zeichenkette oder "cutscr:+Max,Suffix,Zeichenkette")
-  5. eine Zeichenkette umkehren (Format: "rev:xxx" oder "revscr:xxx")
-  6. eine Zeichenkette wiederholen (Format: "repeat:Anzahl,Zeichenkette")
-  7. Länge einer Zeichenkette (Format: "length:xxx" oder "lengthscr:xxx")
-  8. eine Farbe (Format: "color:xxx", siehe "Anleitung für API Erweiterung", Funktion "color")
-  9. ein Modifizierer (Format: "info:Name,Argumente", Argumente sind optional)
-  10. eine Info (Format: "Info:Name,Argumente", Argumente sind optional)
-  11. aktuelles Datum/Uhrzeit (Format: "date" oder "date:format")
-  12. eine Umgebungsvariable (Format: "env:XXX")
-  13. ein Dreifachoperand (Format: "if:Bedingung?Wert_falls_wahr:Wert_falls_unwahr")
-  14. Ergebnis eines Ausdrucks mit Klammern und Operatoren + - * / // % ** (Format: "calc:xxx")
-  15. eine Option (Format: "file.section.option")
-  16. eine lokale Variable eines Buffers
-  17. ein(e) hdata - Name/Variable (der Wert wird automatisch in eine Zeichenkette konvertiert), standardmäßig wird für "window" und "buffer" das aktuelle Fenster/Buffer verwendet.
-Das Format für hdata kann wie folgt aufgebaut sein:
-  hdata.var1.var2...: startet mit hdata (der Pointer muss bekannt sein) und fragt eine Variable nach der anderen ab (weitere hdata können folgen)
-  hdata[list].var1.var2...: startet hdata mittels einer Liste, zum Beispiel:
-    ${buffer[gui_buffers].full_name}: der vollständige Name des ersten Buffers, in der verknüpften Liste aller Buffer
-    ${plugin[weechat_plugins].name}: Name der ersten Erweiterung, in der verknüpften Liste aller Erweiterungen
-  hdata[pointer].var1.var2...: startet hdata mittels einem Pointer, zum Beispiel:
-    ${buffer[0x1234abcd].full_name}: vollständiger Name eines Buffers und des dazugehörigen Pointers (kann in triggern benutzt werden)
-Die vorhandenen Namen für hdata und Variablen sind in der "Anleitung für API Erweiterung", Bereich "weechat_hdata_get". beschrieben
-
-Beispiele (einfache Zeichenketten):
+Some variables are replaced in expression, using the format ${variable}, variable can be, by order of priority:
+  1. an evaluated sub-string (format: "eval:xxx")
+  2. a string with escaped chars (format: "esc:xxx" or "\xxx")
+  3. a string with chars to hide (format: "hide:char,string")
+  4. a string with max chars (format: "cut:max,suffix,string" or "cut:+max,suffix,string")
+     or max chars displayed on screen (format: "cutscr:max,suffix,string" or "cutscr:+max,suffix,string")
+  5. a reversed string (format: "rev:xxx" or "revscr:xxx")
+  6. a repeated string (format: "repeat:count,string")
+  7. length of a string (format: "length:xxx" or "lengthscr:xxx")
+  8. a color (format: "color:xxx", see "Plugin API reference", function "color")
+  9. a modifier (format: "modifier:name,data,string")
+  10. an info (format: "info:name,arguments", arguments are optional)
+  11. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  12. current date/time (format: "date" or "date:format")
+  13. an environment variable (format: "env:XXX")
+  14. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  15. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  16. an option (format: "file.section.option")
+  17. a local variable in buffer
+  18. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+Format for hdata can be one of following:
+  hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
+  hdata[list].var1.var2...: start with a hdata using a list, for example:
+    ${buffer[gui_buffers].full_name}: full name of first buffer in linked list of buffers
+    ${plugin[weechat_plugins].name}: name of first plugin in linked list of plugins
+  hdata[pointer].var1.var2...: start with a hdata using a pointer, for example:
+    ${buffer[0x1234abcd].full_name}: full name of the buffer with this pointer (can be used in triggers)
+For name of hdata and variables, please look at "Plugin API reference", function "weechat_hdata_get".
+
+Examples (simple strings):
   /eval -n ${info:version}                       ==> 0.4.3
   /eval -n ${env:HOME}                           ==> /home/user
   /eval -n ${weechat.look.scroll_amount}         ==> 3
-  /eval -n ${sec.data.freenode_password}         ==> geheim
+  /eval -n ${sec.data.freenode_password}         ==> secret
   /eval -n ${window}                             ==> 0x2549aa0
   /eval -n ${window.buffer}                      ==> 0x2549320
   /eval -n ${window.buffer.full_name}            ==> core.weechat
@@ -1365,18 +1366,20 @@ Beispiele (einfache Zeichenketten):
   /eval -n ${repeat:5,-}                         ==> -----
   /eval -n ${length:test}                        ==> 4
   /eval -n ${calc:(5+2)*3}                       ==> 21
-
-Beispiele (Bedingungen):
-  /eval -n -c ${window.buffer.number} > 2  ==> 0
-  /eval -n -c ${window.win_width} > 100    ==> 1
-  /eval -n -c (8 > 12) || (5 > 2)          ==> 1
-  /eval -n -c (8 > 12) && (5 > 2)          ==> 0
-  /eval -n -c abcd =~ ^ABC                 ==> 1
-  /eval -n -c abcd =~ (?-i)^ABC            ==> 0
-  /eval -n -c abcd =~ (?-i)^abc            ==> 1
-  /eval -n -c abcd !~ abc                  ==> 0
-  /eval -n -c abcd =* a*d                  ==> 1
-  /eval -n -c abcd =- bc                   ==> 1
+  /eval -n ${base_encode:64,test}                ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}            ==> test
+
+Examples (conditions):
+  /eval -n -c ${window.buffer.number} > 2 ==> 0
+  /eval -n -c ${window.win_width} > 100   ==> 1
+  /eval -n -c (8 > 12) || (5 > 2)         ==> 1
+  /eval -n -c (8 > 12) && (5 > 2)         ==> 0
+  /eval -n -c abcd =~ ^ABC                ==> 1
+  /eval -n -c abcd =~ (?-i)^ABC           ==> 0
+  /eval -n -c abcd =~ (?-i)^abc           ==> 1
+  /eval -n -c abcd !~ abc                 ==> 0
+  /eval -n -c abcd =* a*d                 ==> 1
+  /eval -n -c abcd =- bc                  ==> 1
 ----
 
 [[command_weechat_filter]]
diff --git a/doc/en/includes/autogen_user_commands.en.adoc b/doc/en/includes/autogen_user_commands.en.adoc
index 802291c37..745577b9c 100644
--- a/doc/en/includes/autogen_user_commands.en.adoc
+++ b/doc/en/includes/autogen_user_commands.en.adoc
@@ -1330,13 +1330,14 @@ Some variables are replaced in expression, using the format ${variable}, variabl
   8. a color (format: "color:xxx", see "Plugin API reference", function "color")
   9. a modifier (format: "modifier:name,data,string")
   10. an info (format: "info:name,arguments", arguments are optional)
-  11. current date/time (format: "date" or "date:format")
-  12. an environment variable (format: "env:XXX")
-  13. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  14. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  15. an option (format: "file.section.option")
-  16. a local variable in buffer
-  17. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  11. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  12. current date/time (format: "date" or "date:format")
+  13. an environment variable (format: "env:XXX")
+  14. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  15. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  16. an option (format: "file.section.option")
+  17. a local variable in buffer
+  18. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list, for example:
@@ -1365,6 +1366,8 @@ Examples (simple strings):
   /eval -n ${repeat:5,-}                         ==> -----
   /eval -n ${length:test}                        ==> 4
   /eval -n ${calc:(5+2)*3}                       ==> 21
+  /eval -n ${base_encode:64,test}                ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}            ==> test
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/en/weechat_plugin_api.en.adoc b/doc/en/weechat_plugin_api.en.adoc
index 297d6228b..b6bbddb37 100644
--- a/doc/en/weechat_plugin_api.en.adoc
+++ b/doc/en/weechat_plugin_api.en.adoc
@@ -2594,6 +2594,26 @@ expanded to last):
   `+1.0+` +
   `+lightblue+`
 
+| `+${base_encode:base,xxx}+` +
+  _(WeeChat ≥ 2.9)_ |
+  String encoded in base 16, 32 or 64. |
+  `+${base_encode:16,test string}+` +
+  `+${base_encode:32,test string}+` +
+  `+${base_encode:64,test string}+` |
+  `+7465737420737472696E67+` +
+  `+ORSXG5BAON2HE2LOM4======+` +
+  `+dGVzdCBzdHJpbmc=+`
+
+| `+${base_decode:base,xxx}+` +
+  _(WeeChat ≥ 2.9)_ |
+  String decoded from base 16, 32 or 64. |
+  `+${base_decode:16,7465737420737472696E67}+` +
+  `+${base_decode:32,ORSXG5BAON2HE2LOM4======}+` +
+  `+${base_decode:64,dGVzdCBzdHJpbmc=}+` |
+  `+test string+` +
+  `+test string+` +
+  `+test string+`
+
 | `+${date}+` +
   `+${date:xxx}+` +
   _(WeeChat ≥ 1.3)_ |
diff --git a/doc/fr/includes/autogen_user_commands.fr.adoc b/doc/fr/includes/autogen_user_commands.fr.adoc
index 2b137074c..505bac1f5 100644
--- a/doc/fr/includes/autogen_user_commands.fr.adoc
+++ b/doc/fr/includes/autogen_user_commands.fr.adoc
@@ -1330,13 +1330,14 @@ Des variables sont remplacées dans l'expression, en utilisant le format ${varia
   8. une couleur (format : "color:xxx", voir la "Référence API extension", fonction "color")
   9. un modificateur (format : "modifier:nom,données,chaîne")
   10. une info (format : "info:nom,paramètres", les paramètres sont optionnels)
-  11. la date/heure courante (format : "date" ou "date:format")
-  12. une variable d'environnement (format : "env:XXX")
-  13. un opérateur ternaire (format : "if:condition?valeur_si_vrai:valeur_si_faux")
-  14. le résultat d'une expression avec parenthèses et les opérateurs + - * / // % ** (format: "calc:xxx")
-  15. une option (format : "fichier.section.option")
-  16. une variable locale du tampon
-  17. un hdata/variable (la valeur est automatiquement convertie en chaîne), par défaut "window" et "buffer" pointent vers la fenêtre et le tampon courants.
+  11. une chaîne encodée/decodée en base 16, 32 ou 64 (format : "base_encode:base,xxx" ou "base_decode:base,xxx")
+  12. la date/heure courante (format : "date" ou "date:format")
+  13. une variable d'environnement (format : "env:XXX")
+  14. un opérateur ternaire (format : "if:condition?valeur_si_vrai:valeur_si_faux")
+  15. le résultat d'une expression avec parenthèses et les opérateurs + - * / // % ** (format: "calc:xxx")
+  16. une option (format : "fichier.section.option")
+  17. une variable locale du tampon
+  18. un hdata/variable (la valeur est automatiquement convertie en chaîne), par défaut "window" et "buffer" pointent vers la fenêtre et le tampon courants.
 Le format du hdata peut être le suivant :
   hdata.var1.var2... : démarrer avec un hdata (le pointeur doit être connu), et demander les variables l'une après l'autre (d'autres hdata peuvent être suivis)
   hdata[liste].var1.var2... : démarrer avec un hdata en utilisant une liste, par exemple :
@@ -1365,6 +1366,8 @@ Exemples (chaînes simples) :
   /eval -n ${repeat:5,-}                         ==> -----
   /eval -n ${length:test}                        ==> 4
   /eval -n ${calc:(5+2)*3}                       ==> 21
+  /eval -n ${base_encode:64,test}                ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}            ==> test
 
 Exemples (conditions) :
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/fr/weechat_plugin_api.fr.adoc b/doc/fr/weechat_plugin_api.fr.adoc
index 20cb2f0bb..b6892d6fc 100644
--- a/doc/fr/weechat_plugin_api.fr.adoc
+++ b/doc/fr/weechat_plugin_api.fr.adoc
@@ -2640,6 +2640,27 @@ première étendue à la dernière) :
   `+1.0+` +
   `+lightblue+`
 
+| `+${base_encode:base,xxx}+` +
+  _(WeeChat ≥ 2.9)_ |
+  Chaîne encodée en base 16, 32 ou 64. |
+  `+${base_encode:16,test string}+` +
+  `+${base_encode:32,test string}+` +
+  `+${base_encode:64,test string}+` |
+  `+7465737420737472696E67+` +
+  `+ORSXG5BAON2HE2LOM4======+` +
+  `+dGVzdCBzdHJpbmc=+`
+
+// TRANSLATION MISSING
+| `+${base_decode:base,xxx}+` +
+  _(WeeChat ≥ 2.9)_ |
+  Chaîne décodée depuis base 16, 32 ou 64. |
+  `+${base_decode:16,7465737420737472696E67}+` +
+  `+${base_decode:32,ORSXG5BAON2HE2LOM4======}+` +
+  `+${base_decode:64,dGVzdCBzdHJpbmc=}+` |
+  `+test string+` +
+  `+test string+` +
+  `+test string+`
+
 | `+${date}+` +
   `+${date:xxx}+` +
   _(WeeChat ≥ 1.3)_ |
diff --git a/doc/it/includes/autogen_user_commands.it.adoc b/doc/it/includes/autogen_user_commands.it.adoc
index cf41d11cf..f8a904031 100644
--- a/doc/it/includes/autogen_user_commands.it.adoc
+++ b/doc/it/includes/autogen_user_commands.it.adoc
@@ -1330,13 +1330,14 @@ Some variables are replaced in expression, using the format ${variable}, variabl
   8. a color (format: "color:xxx", see "Plugin API reference", function "color")
   9. a modifier (format: "modifier:name,data,string")
   10. an info (format: "info:name,arguments", arguments are optional)
-  11. current date/time (format: "date" or "date:format")
-  12. an environment variable (format: "env:XXX")
-  13. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  14. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  15. an option (format: "file.section.option")
-  16. a local variable in buffer
-  17. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  11. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  12. current date/time (format: "date" or "date:format")
+  13. an environment variable (format: "env:XXX")
+  14. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  15. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  16. an option (format: "file.section.option")
+  17. a local variable in buffer
+  18. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list, for example:
@@ -1365,6 +1366,8 @@ Examples (simple strings):
   /eval -n ${repeat:5,-}                         ==> -----
   /eval -n ${length:test}                        ==> 4
   /eval -n ${calc:(5+2)*3}                       ==> 21
+  /eval -n ${base_encode:64,test}                ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}            ==> test
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/it/weechat_plugin_api.it.adoc b/doc/it/weechat_plugin_api.it.adoc
index 2e68892e0..9ebed0c14 100644
--- a/doc/it/weechat_plugin_api.it.adoc
+++ b/doc/it/weechat_plugin_api.it.adoc
@@ -2701,6 +2701,28 @@ expanded to last):
   `+1.0+` +
   `+lightblue+`
 
+// TRANSLATION MISSING
+| `+${base_encode:base,xxx}+` +
+  _(WeeChat ≥ 2.9)_ |
+  String encoded in base 16, 32 or 64. |
+  `+${base_encode:16,test string}+` +
+  `+${base_encode:32,test string}+` +
+  `+${base_encode:64,test string}+` |
+  `+7465737420737472696E67+` +
+  `+ORSXG5BAON2HE2LOM4======+` +
+  `+dGVzdCBzdHJpbmc=+`
+
+// TRANSLATION MISSING
+| `+${base_decode:base,xxx}+` +
+  _(WeeChat ≥ 2.9)_ |
+  String decoded from base 16, 32 or 64. |
+  `+${base_decode:16,7465737420737472696E67}+` +
+  `+${base_decode:32,ORSXG5BAON2HE2LOM4======}+` +
+  `+${base_decode:64,dGVzdCBzdHJpbmc=}+` |
+  `+test string+` +
+  `+test string+` +
+  `+test string+`
+
 | `+${date}+` +
   `+${date:xxx}+` +
   _(WeeChat ≥ 1.3)_ |
diff --git a/doc/ja/includes/autogen_user_commands.ja.adoc b/doc/ja/includes/autogen_user_commands.ja.adoc
index 4cccd9cf1..90e0d0fdc 100644
--- a/doc/ja/includes/autogen_user_commands.ja.adoc
+++ b/doc/ja/includes/autogen_user_commands.ja.adoc
@@ -1330,13 +1330,14 @@ Some variables are replaced in expression, using the format ${variable}, variabl
   8. a color (format: "color:xxx", see "Plugin API reference", function "color")
   9. a modifier (format: "modifier:name,data,string")
   10. an info (format: "info:name,arguments", arguments are optional)
-  11. current date/time (format: "date" or "date:format")
-  12. an environment variable (format: "env:XXX")
-  13. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  14. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  15. an option (format: "file.section.option")
-  16. a local variable in buffer
-  17. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  11. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  12. current date/time (format: "date" or "date:format")
+  13. an environment variable (format: "env:XXX")
+  14. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  15. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  16. an option (format: "file.section.option")
+  17. a local variable in buffer
+  18. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list, for example:
@@ -1365,6 +1366,8 @@ Examples (simple strings):
   /eval -n ${repeat:5,-}                         ==> -----
   /eval -n ${length:test}                        ==> 4
   /eval -n ${calc:(5+2)*3}                       ==> 21
+  /eval -n ${base_encode:64,test}                ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}            ==> test
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/doc/ja/weechat_plugin_api.ja.adoc b/doc/ja/weechat_plugin_api.ja.adoc
index 17279d34d..cba0bc1cc 100644
--- a/doc/ja/weechat_plugin_api.ja.adoc
+++ b/doc/ja/weechat_plugin_api.ja.adoc
@@ -2619,6 +2619,28 @@ str5 = weechat.string_eval_expression("password=abc password=def", {}, {}, optio
   `+1.0+` +
   `+lightblue+`
 
+// TRANSLATION MISSING
+| `+${base_encode:base,xxx}+` +
+  _(WeeChat バージョン 2.9 以上で利用可)_ |
+  String encoded in base 16, 32 or 64. |
+  `+${base_encode:16,test string}+` +
+  `+${base_encode:32,test string}+` +
+  `+${base_encode:64,test string}+` |
+  `+7465737420737472696E67+` +
+  `+ORSXG5BAON2HE2LOM4======+` +
+  `+dGVzdCBzdHJpbmc=+`
+
+// TRANSLATION MISSING
+| `+${base_decode:base,xxx}+` +
+  _(WeeChat バージョン 2.9 以上で利用可)_ |
+  String decoded from base 16, 32 or 64. |
+  `+${base_decode:16,7465737420737472696E67}+` +
+  `+${base_decode:32,ORSXG5BAON2HE2LOM4======}+` +
+  `+${base_decode:64,dGVzdCBzdHJpbmc=}+` |
+  `+test string+` +
+  `+test string+` +
+  `+test string+`
+
 | `+${date}+` +
   `+${date:xxx}+` +
   _(WeeChat バージョン 1.3 以上で利用可)_ |
diff --git a/doc/pl/includes/autogen_user_commands.pl.adoc b/doc/pl/includes/autogen_user_commands.pl.adoc
index a10add604..38ffdc88e 100644
--- a/doc/pl/includes/autogen_user_commands.pl.adoc
+++ b/doc/pl/includes/autogen_user_commands.pl.adoc
@@ -1329,13 +1329,14 @@ Some variables are replaced in expression, using the format ${variable}, variabl
   8. a color (format: "color:xxx", see "Plugin API reference", function "color")
   9. a modifier (format: "modifier:name,data,string")
   10. an info (format: "info:name,arguments", arguments are optional)
-  11. current date/time (format: "date" or "date:format")
-  12. an environment variable (format: "env:XXX")
-  13. a ternary operator (format: "if:condition?value_if_true:value_if_false")
-  14. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
-  15. an option (format: "file.section.option")
-  16. a local variable in buffer
-  17. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
+  11. a base 16/32/64 encoded/decoded string (format: "base_encode:base,xxx" or "base_decode:base,xxx")
+  12. current date/time (format: "date" or "date:format")
+  13. an environment variable (format: "env:XXX")
+  14. a ternary operator (format: "if:condition?value_if_true:value_if_false")
+  15. result of an expression with parentheses and operators + - * / // % ** (format: "calc:xxx")
+  16. an option (format: "file.section.option")
+  17. a local variable in buffer
+  18. a hdata name/variable (the value is automatically converted to string), by default "window" and "buffer" point to current window/buffer.
 Format for hdata can be one of following:
   hdata.var1.var2...: start with a hdata (pointer must be known), and ask variables one after one (other hdata can be followed)
   hdata[list].var1.var2...: start with a hdata using a list, for example:
@@ -1364,6 +1365,8 @@ Examples (simple strings):
   /eval -n ${repeat:5,-}                         ==> -----
   /eval -n ${length:test}                        ==> 4
   /eval -n ${calc:(5+2)*3}                       ==> 21
+  /eval -n ${base_encode:64,test}                ==> dGVzdA==
+  /eval -n ${base_decode:64,dGVzdA==}            ==> test
 
 Examples (conditions):
   /eval -n -c ${window.buffer.number} > 2 ==> 0
diff --git a/po/cs.po b/po/cs.po
index fc7b6ffa2..f1c879d8f 100644
--- a/po/cs.po
+++ b/po/cs.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Ondřej Súkup <mimi.vx@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1604,15 +1604,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1649,6 +1651,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/de.po b/po/de.po
index 72bb580e2..066fde122 100644
--- a/po/de.po
+++ b/po/de.po
@@ -24,7 +24,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-05-08 19:58+0200\n"
 "Last-Translator: Nils Görs <weechatter@arcor.de>\n"
 "Language-Team: German <kde-i18n-de@kde.org>\n"
@@ -1684,6 +1684,7 @@ msgstr ""
 "[-n|-s] [-d] <expression> || [-n] [-d] -c <expression1> <operator> "
 "<expression2>"
 
+#, fuzzy
 msgid ""
 "        -n: display result without sending it to buffer (debug mode)\n"
 "        -s: split expression before evaluating it (many commands can be "
@@ -1747,15 +1748,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1792,6 +1795,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/es.po b/po/es.po
index 4e0441000..d14ae6a4d 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Elián Hanisch <lambdae2@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1634,15 +1634,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1679,6 +1681,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/fr.po b/po/fr.po
index 34c975d4c..36af31b9a 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: 2020-05-16 14:36+0200\n"
-"PO-Revision-Date: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
+"PO-Revision-Date: 2020-05-21 09:19+0200\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
 "Language: fr\n"
@@ -1717,15 +1717,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1762,6 +1764,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
@@ -1842,15 +1846,17 @@ msgstr ""
 "  9. un modificateur (format : \"modifier:nom,données,chaîne\")\n"
 "  10. une info (format : \"info:nom,paramètres\", les paramètres sont "
 "optionnels)\n"
-"  11. la date/heure courante (format : \"date\" ou \"date:format\")\n"
-"  12. une variable d'environnement (format : \"env:XXX\")\n"
-"  13. un opérateur ternaire (format : \"if:condition?valeur_si_vrai:"
+"  11. une chaîne encodée/decodée en base 16, 32 ou 64 (format : "
+"\"base_encode:base,xxx\" ou \"base_decode:base,xxx\")\n"
+"  12. la date/heure courante (format : \"date\" ou \"date:format\")\n"
+"  13. une variable d'environnement (format : \"env:XXX\")\n"
+"  14. un opérateur ternaire (format : \"if:condition?valeur_si_vrai:"
 "valeur_si_faux\")\n"
-"  14. le résultat d'une expression avec parenthèses et les opérateurs + - "
+"  15. le résultat d'une expression avec parenthèses et les opérateurs + - "
 "* / // % ** (format: \"calc:xxx\")\n"
-"  15. une option (format : \"fichier.section.option\")\n"
-"  16. une variable locale du tampon\n"
-"  17. un hdata/variable (la valeur est automatiquement convertie en chaîne), "
+"  16. une option (format : \"fichier.section.option\")\n"
+"  17. une variable locale du tampon\n"
+"  18. un hdata/variable (la valeur est automatiquement convertie en chaîne), "
 "par défaut \"window\" et \"buffer\" pointent vers la fenêtre et le tampon "
 "courants.\n"
 "Le format du hdata peut être le suivant :\n"
@@ -1889,6 +1895,8 @@ msgstr ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Exemples (conditions) :\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/hu.po b/po/hu.po
index 3a0e65c30..118425c22 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Andras Voroskoi <voroskoi@frugalware.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1522,15 +1522,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1567,6 +1569,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/it.po b/po/it.po
index 8bc76277d..1004640ad 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Esteban I. Ruiz Moreno <exio4.com@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1617,15 +1617,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1662,6 +1664,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/ja.po b/po/ja.po
index b63e1a5d4..03bdfb54d 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: AYANOKOUZI, Ryuunosuke <i38w7i3@yahoo.co.jp>\n"
 "Language-Team: Japanese <https://github.com/l/weechat/tree/master/"
@@ -1674,15 +1674,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1719,6 +1721,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/pl.po b/po/pl.po
index 4a8352b2f..39faacba9 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Krzysztof Korościk <soltys@soltys.info>\n"
 "Language-Team: Polish <kde-i18n-doc@kde.org>\n"
@@ -1710,15 +1710,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1755,6 +1757,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/pt.po b/po/pt.po
index de9141d17..ee8408c5a 100644
--- a/po/pt.po
+++ b/po/pt.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Vasco Almeida <vascomalmeida@sapo.pt>\n"
 "Language-Team: Portuguese <>\n"
@@ -1676,15 +1676,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1721,6 +1723,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/pt_BR.po b/po/pt_BR.po
index ffdf68845..7081391a7 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-18 11:34+0200\n"
 "Last-Translator: Eduardo Elias <camponez@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1680,15 +1680,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1725,6 +1727,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/ru.po b/po/ru.po
index 0459e2718..f8df6dac6 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2020-04-28 16:40+0200\n"
 "Last-Translator: Aleksey V Zapparov AKA ixti <ixti@member.fsf.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1544,15 +1544,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1589,6 +1591,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/tr.po b/po/tr.po
index de3801a3a..6335c4d8f 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: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2019-11-03 08:38+0100\n"
 "Last-Translator: Hasan Kiran <sunder67@hotmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1375,15 +1375,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1420,6 +1422,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/po/weechat.pot b/po/weechat.pot
index 6fbaae2ef..b448bfe5d 100644
--- a/po/weechat.pot
+++ b/po/weechat.pot
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2020-05-16 14:36+0200\n"
+"POT-Creation-Date: 2020-05-21 09:18+0200\n"
 "PO-Revision-Date: 2014-08-16 10:27+0200\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -1377,15 +1377,17 @@ msgid ""
 "\"color\")\n"
 "  9. a modifier (format: \"modifier:name,data,string\")\n"
 "  10. an info (format: \"info:name,arguments\", arguments are optional)\n"
-"  11. current date/time (format: \"date\" or \"date:format\")\n"
-"  12. an environment variable (format: \"env:XXX\")\n"
-"  13. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
+"  11. a base 16/32/64 encoded/decoded string (format: \"base_encode:base,xxx"
+"\" or \"base_decode:base,xxx\")\n"
+"  12. current date/time (format: \"date\" or \"date:format\")\n"
+"  13. an environment variable (format: \"env:XXX\")\n"
+"  14. a ternary operator (format: \"if:condition?value_if_true:value_if_false"
 "\")\n"
-"  14. result of an expression with parentheses and operators + - * / // % ** "
+"  15. result of an expression with parentheses and operators + - * / // % ** "
 "(format: \"calc:xxx\")\n"
-"  15. an option (format: \"file.section.option\")\n"
-"  16. a local variable in buffer\n"
-"  17. a hdata name/variable (the value is automatically converted to "
+"  16. an option (format: \"file.section.option\")\n"
+"  17. a local variable in buffer\n"
+"  18. a hdata name/variable (the value is automatically converted to "
 "string), by default \"window\" and \"buffer\" point to current window/"
 "buffer.\n"
 "Format for hdata can be one of following:\n"
@@ -1422,6 +1424,8 @@ msgid ""
 "  /eval -n ${repeat:5,-}                         ==> -----\n"
 "  /eval -n ${length:test}                        ==> 4\n"
 "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+"  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+"  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
 "\n"
 "Examples (conditions):\n"
 "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/src/core/wee-command.c b/src/core/wee-command.c
index 962d69f97..acde2d3cc 100644
--- a/src/core/wee-command.c
+++ b/src/core/wee-command.c
@@ -7435,15 +7435,17 @@ command_init ()
            "  9. a modifier (format: \"modifier:name,data,string\")\n"
            "  10. an info (format: \"info:name,arguments\", arguments are "
            "optional)\n"
-           "  11. current date/time (format: \"date\" or \"date:format\")\n"
-           "  12. an environment variable (format: \"env:XXX\")\n"
-           "  13. a ternary operator (format: "
+           "  11. a base 16/32/64 encoded/decoded string (format: "
+           "\"base_encode:base,xxx\" or \"base_decode:base,xxx\")\n"
+           "  12. current date/time (format: \"date\" or \"date:format\")\n"
+           "  13. an environment variable (format: \"env:XXX\")\n"
+           "  14. a ternary operator (format: "
            "\"if:condition?value_if_true:value_if_false\")\n"
-           "  14. result of an expression with parentheses and operators "
+           "  15. result of an expression with parentheses and operators "
            "+ - * / // % ** (format: \"calc:xxx\")\n"
-           "  15. an option (format: \"file.section.option\")\n"
-           "  16. a local variable in buffer\n"
-           "  17. a hdata name/variable (the value is automatically converted "
+           "  16. an option (format: \"file.section.option\")\n"
+           "  17. a local variable in buffer\n"
+           "  18. a hdata name/variable (the value is automatically converted "
            "to string), by default \"window\" and \"buffer\" point to current "
            "window/buffer.\n"
            "Format for hdata can be one of following:\n"
@@ -7481,6 +7483,8 @@ command_init ()
            "  /eval -n ${repeat:5,-}                         ==> -----\n"
            "  /eval -n ${length:test}                        ==> 4\n"
            "  /eval -n ${calc:(5+2)*3}                       ==> 21\n"
+           "  /eval -n ${base_encode:64,test}                ==> dGVzdA==\n"
+           "  /eval -n ${base_decode:64,dGVzdA==}            ==> test\n"
            "\n"
            "Examples (conditions):\n"
            "  /eval -n -c ${window.buffer.number} > 2 ==> 0\n"
diff --git a/src/core/wee-eval.c b/src/core/wee-eval.c
index c80322031..4d64c641f 100644
--- a/src/core/wee-eval.c
+++ b/src/core/wee-eval.c
@@ -423,6 +423,7 @@ eval_string_info (const char *text)
     char *value, *info_name;
 
     value = NULL;
+
     ptr_arguments = strchr (text, ',');
     if (ptr_arguments)
     {
@@ -430,7 +431,10 @@ eval_string_info (const char *text)
         ptr_arguments++;
     }
     else
+    {
         info_name = strdup (text);
+    }
+
     if (info_name)
     {
         value = hook_info_get (NULL, info_name, ptr_arguments);
@@ -441,6 +445,104 @@ eval_string_info (const char *text)
 }
 
 /*
+ * Encodes a string in base 16, 32, or 64.
+ *
+ * Note: result must be freed after use.
+ */
+
+char *
+eval_string_base_encode (const char *text)
+{
+    const char *ptr_string;
+    char *value, *base, *error, *result;
+    long number;
+    int length;
+
+    base = NULL;
+    result = NULL;
+
+    ptr_string = strchr (text, ',');
+    if (!ptr_string)
+        goto end;
+
+    base = string_strndup (text, ptr_string - text);
+    if (!base)
+        goto end;
+
+    number = strtol (base, &error, 10);
+    if (!error || error[0])
+        goto end;
+
+    ptr_string++;
+    length = strlen (ptr_string);
+    result = malloc ((length * 4) + 1);
+    if (!result)
+        goto end;
+
+    if (string_base_encode (number, ptr_string, length, result) < 0)
+    {
+        free (result);
+        result = NULL;
+    }
+
+end:
+    value = strdup ((result) ? result : "");
+    if (base)
+        free (base);
+    if (result)
+        free (result);
+    return value;
+}
+
+/*
+ * Decodes a string encoded in base 16, 32, or 64.
+ *
+ * Note: result must be freed after use.
+ */
+
+char *
+eval_string_base_decode (const char *text)
+{
+    const char *ptr_string;
+    char *value, *base, *error, *result;
+    long number;
+
+    base = NULL;
+    result = NULL;
+
+    ptr_string = strchr (text, ',');
+    if (!ptr_string)
+        goto end;
+
+    base = string_strndup (text, ptr_string - text);
+    if (!base)
+        goto end;
+
+    number = strtol (base, &error, 10);
+    if (!error || error[0])
+        goto end;
+
+    ptr_string++;
+    result = malloc (strlen (ptr_string) + 1);
+    if (!result)
+        goto end;
+
+    if (string_base_decode (number, ptr_string, result) < 0)
+    {
+        free (result);
+        result = NULL;
+    }
+
+end:
+    value = strdup ((result) ? result : "");
+    if (base)
+        free (base);
+    if (result)
+        free (result);
+    return value;
+}
+
+/*
  * Returns a date.
  *
  * Note: result must be freed after use.
@@ -805,13 +907,15 @@ end:
  *  10. a color (format: color:xxx)
  *  11. a modifier (format: modifier:name,data,xxx)
  *  12. an info (format: info:name,arguments)
- *  13. current date/time (format: date or date:xxx)
- *  14. an environment variable (format: env:XXX)
- *  15. a ternary operator (format: if:condition?value_if_true:value_if_false)
- *  16. calculate result of an expression (format: calc:xxx)
- *  17. an option (format: file.section.option)
- *  18. a buffer local variable
- *  19. a hdata variable (format: hdata.var1.var2 or hdata[list].var1.var2
+ *  13. a base 16/32/64 encoded/decoded string (format: base_encode:base,xxx
+ *      or base_decode:base,xxx)
+ *  14. current date/time (format: date or date:xxx)
+ *  15. an environment variable (format: env:XXX)
+ *  16. a ternary operator (format: if:condition?value_if_true:value_if_false)
+ *  17. calculate result of an expression (format: calc:xxx)
+ *  18. an option (format: file.section.option)
+ *  19. a buffer local variable
+ *  20. a hdata variable (format: hdata.var1.var2 or hdata[list].var1.var2
  *                        or hdata[ptr].var1.var2)
  *
  * See /help in WeeChat for examples.
@@ -931,11 +1035,17 @@ eval_replace_vars_cb (void *data, const char *text)
     if (strncmp (text, "info:", 5) == 0)
         return eval_string_info (text + 5);
 
-    /* 13. current date/time */
+    /* 13. base_encode/base_decode */
+    if (strncmp (text, "base_encode:", 12) == 0)
+        return eval_string_base_encode (text + 12);
+    if (strncmp (text, "base_decode:", 12) == 0)
+        return eval_string_base_decode (text + 12);
+
+    /* 14. current date/time */
     if ((strncmp (text, "date", 4) == 0) && (!text[4] || (text[4] == ':')))
         return eval_string_date (text + 4);
 
-    /* 14. environment variable */
+    /* 15. environment variable */
     if (strncmp (text, "env:", 4) == 0)
     {
         ptr_value = getenv (text + 4);
@@ -943,18 +1053,18 @@ eval_replace_vars_cb (void *data, const char *text)
             return strdup (ptr_value);
     }
 
-    /* 15: ternary operator: if:condition?value_if_true:value_if_false */
+    /* 16: ternary operator: if:condition?value_if_true:value_if_false */
     if (strncmp (text, "if:", 3) == 0)
         return eval_string_if (text + 3, eval_context);
 
     /*
-     * 16. calculate the result of an expression
+     * 17. calculate the result of an expression
      * (with number, operators and parentheses)
      */
     if (strncmp (text, "calc:", 5) == 0)
         return calc_expression (text + 5);
 
-    /* 17. option: if found, return this value */
+    /* 18. option: if found, return this value */
     if (strncmp (text, "sec.data.", 9) == 0)
     {
         ptr_value = hashtable_get (secure_hashtable_data, text + 9);
@@ -984,7 +1094,7 @@ eval_replace_vars_cb (void *data, const char *text)
         }
     }
 
-    /* 18. local variable in buffer */
+    /* 19. local variable in buffer */
     ptr_buffer = hashtable_get (eval_context->pointers, "buffer");
     if (ptr_buffer)
     {
@@ -993,7 +1103,7 @@ eval_replace_vars_cb (void *data, const char *text)
             return strdup (ptr_value);
     }
 
-    /* 19. hdata */
+    /* 20. hdata */
     return eval_string_hdata (text, eval_context);
 }
 
diff --git a/tests/unit/core/test-core-eval.cpp b/tests/unit/core/test-core-eval.cpp
index 65f6a0c76..6126a6dd6 100644
--- a/tests/unit/core/test-core-eval.cpp
+++ b/tests/unit/core/test-core-eval.cpp
@@ -563,6 +563,22 @@ TEST(CoreEval, EvalExpression)
     /* test info */
     WEE_CHECK_EVAL(version_get_version (), "${info:version}");
 
+    /* test base_encode */
+    WEE_CHECK_EVAL("", "${base_encode:}");
+    WEE_CHECK_EVAL("", "${base_encode:0,xxx}");
+    WEE_CHECK_EVAL("", "${base_encode:100,test string}");
+    WEE_CHECK_EVAL("7465737420737472696E67", "${base_encode:16,test string}");
+    WEE_CHECK_EVAL("ORSXG5BAON2HE2LOM4======", "${base_encode:32,test string}");
+    WEE_CHECK_EVAL("dGVzdCBzdHJpbmc=", "${base_encode:64,test string}");
+
+    /* test base_decode */
+    WEE_CHECK_EVAL("", "${base_decode:}");
+    WEE_CHECK_EVAL("", "${base_decode:0,xxx}");
+    WEE_CHECK_EVAL("", "${base_decode:100,test string}");
+    WEE_CHECK_EVAL("test string", "${base_decode:16,7465737420737472696E67}");
+    WEE_CHECK_EVAL("test string", "${base_decode:32,ORSXG5BAON2HE2LOM4======}");
+    WEE_CHECK_EVAL("test string", "${base_decode:64,dGVzdCBzdHJpbmc=}");
+
     /* test date */
     WEE_CHECK_EVAL("", "${date:}");
     value = eval_expression ("${date}", pointers, extra_vars, options);