core: add cut of string in evaluation of expressions

The syntax is: ${cut:max,suffix,string}.
The string is cut after max chars. If the string is cut, the optional suffix is
added after.

doc/en/weechat_plugin_api.en.adoc

@@ -2035,11 +2035,19 @@ expanded to last):
   `+prefix<TAB>message+` +
   `+©+`
 
-| `+${hide:x,value}+` |
-  String with hidden chars (all chars in `value` replaced by `x`). |
+| `+${hide:x,string}+` |
+  String with hidden chars (all chars in `string` replaced by `x`). |
   `+${hide:*,password}+` |
   `+********+`
 
+| `+${cut:max,suffix,string}+` +
+  (_WeeChat ≥ 1.8_) |
+  String with `max` chars displayed, and optional `suffix` if string is cut. |
+  `+${cut:4,…,this is a test}+` +
+  `+${cut:2,>>,àéçôî}+` |
+  `+this…+` +
+  `+àé>>+`
+
 | `+${re:N}+` |
   Regex captured group: `0` = whole string matching, `1` to `99` = group
   captured, `+++` = last group captured. |

doc/fr/weechat_plugin_api.fr.adoc

@@ -2077,12 +2077,20 @@ première étendue à la dernière) :
   `+préfixe<TAB>message+` +
   `+©+`
 
-| `+${hide:x,valeur}+` |
-  Chaîne avec les caractères masqués (tous les caractères dans `valeur`
-  remplacés par `x`. |
+| `+${hide:x,chaîne}+` |
+  Chaîne avec les caractères masqués (tous les caractères dans `chaîne`
+  remplacés par `x`). |
   `+${hide:*,mot_de_passe}+` |
   `+************+`
 
+| `+${cut:max,suffixe,chaîne}+` +
+  (_WeeChat ≥ 1.8_) |
+  Chaîne avec `max` caractères affichés, et un `suffixe` facultatif si la chaîne est coupée. |
+  `+${cut:4,…,ceci est un test}+` +
+  `+${cut:2,>>,àéçôî}+` |
+  `+ceci…+` +
+  `+àé>>+`
+
 | `+${re:N}+` |
   Groupe regex capturé : `0` = toute la chaîne correspondante,
   `1` à `99` = groupe capturé, `+++` = dernier groupe capturé. |

doc/it/weechat_plugin_api.it.adoc

@@ -2113,11 +2113,19 @@ expanded to last):
   `+prefix<TAB>message+` +
   `+©+`
 
-| `+${hide:x,value}+` |
-  String with hidden chars (all chars in `value` replaced `x`). |
+| `+${hide:x,string}+` |
+  String with hidden chars (all chars in `string` replaced `x`). |
   `+${hide:*,password}+` |
   `+********+`
 
+| `+${cut:max,suffix,string}+` +
+  (_WeeChat ≥ 1.8_) |
+  String with `max` chars displayed, and optional `suffix` if string is cut. |
+  `+${cut:4,…,this is a test}+` +
+  `+${cut:2,>>,àéçôî}+` |
+  `+this…+` +
+  `+àé>>+`
+
 | `+${re:N}+` |
   Regex captured group: `0` = whole string matching, `1` to `99` = group
   captured, `+++` = last group captured. |

doc/ja/weechat_plugin_api.ja.adoc

@@ -2041,11 +2041,20 @@ char *weechat_string_eval_expression (const char *expr,
   `+prefix<TAB>message+` +
   `+©+`
 
-| `+${hide:x,value}+` |
-  隠す文字を含むテキスト (`value` に含まれる文字をすべて `x` で置換) |
+| `+${hide:x,string}+` |
+  隠す文字を含むテキスト (`string` に含まれる文字をすべて `x` で置換) |
   `+${hide:*,password}+` |
  `+********+`
 
+// TRANSLATION MISSING
+| `+${cut:max,suffix,string}+` +
+  (_WeeChat バージョン 1.8 以上で利用可_) |
+  String with `max` chars displayed, and optional `suffix` if string is cut. |
+  `+${cut:4,…,this is a test}+` +
+  `+${cut:2,>>,àéçôî}+` |
+  `+this…+` +
+  `+àé>>+`
+
 | `+${re:N}+` |
   正規表現のキャプチャグループ: `0` = マッチするすべての文字列、`1` から `99` =
   キャプチャされたグループ、`+++` = 最後にキャプチャされたグループ |

src/core/wee-string.c

@@ -51,6 +51,7 @@
 #include "wee-eval.h"
 #include "wee-hashtable.h"
 #include "wee-utf8.h"
+#include "../gui/gui-chat.h"
 #include "../gui/gui-color.h"
 #include "../plugins/plugin.h"
 
@@ -91,6 +92,45 @@ string_strndup (const char *string, int length)
     return result;
 }
 
+/*
+ * Cuts a string after max "length" chars, adds an optional suffix
+ * after the string if it is cut.
+ *
+ * Note: result must be freed after use.
+ */
+
+char *
+string_cut (const char *string, int length, const char *cut_suffix)
+{
+    int length_result, length_cut_suffix;
+    char *result;
+    const char *ptr_string;
+
+    ptr_string = gui_chat_string_add_offset (string, length);
+    if (!ptr_string[0])
+    {
+        /* no cut */
+        return strdup (string);
+    }
+
+    if (cut_suffix && cut_suffix[0])
+    {
+        length_cut_suffix = strlen (cut_suffix);
+        length_result = (ptr_string - string) + length_cut_suffix + 1;
+        result = malloc (length_result);
+        if (!result)
+            return NULL;
+        memcpy (result, string, ptr_string - string);
+        memcpy (result + (ptr_string - string), cut_suffix,
+                length_cut_suffix + 1);
+        return result;
+    }
+    else
+    {
+        return string_strndup (string, ptr_string - string);
+    }
+}
+
 /*
  * Converts string to lower case (locale independent).
  */

src/core/wee-string.h

@@ -36,6 +36,8 @@ struct t_string_dyn
 struct t_hashtable;
 
 extern char *string_strndup (const char *string, int length);
+extern char *string_cut (const char *string, int length,
+                         const char *cut_suffix);
 extern void string_tolower (char *string);
 extern void string_toupper (char *string);
 extern int string_strcasecmp (const char *string1, const char *string2);

tests/unit/core/test-eval.cpp

@@ -218,6 +218,16 @@ TEST(Eval, EvalExpression)
     WEE_CHECK_EVAL("********", "${hide:*,password}");
     WEE_CHECK_EVAL("\u2603\u2603\u2603", "${hide:${esc:\u2603},abc}");
 
+    /* test cut of chars */
+    WEE_CHECK_EVAL("", "${cut:0,,}");
+    WEE_CHECK_EVAL("", "${cut:0,+,}");
+    WEE_CHECK_EVAL("", "${cut:0,,test}");
+    WEE_CHECK_EVAL("+", "${cut:0,+,test}");
+    WEE_CHECK_EVAL("te", "${cut:2,,test}");
+    WEE_CHECK_EVAL("te+", "${cut:2,+,test}");
+    WEE_CHECK_EVAL("éà", "${cut:2,,éàô}");
+    WEE_CHECK_EVAL("éà+", "${cut:2,+,éàô}");
+
     /* test color */
     WEE_CHECK_EVAL(gui_color_get_custom ("green"), "${color:green}");
     WEE_CHECK_EVAL(gui_color_get_custom ("*214"), "${color:*214}");