"!": history search mode that matches only the start of strings

The gtk entry must be emtpy before pressing "!"

It enters a special (history) search mode that only
matches the start of strings, a reverse search

hit CTRL-R or CTRL-S to extend search backwards or forwards

README.md

@@ -23,7 +23,8 @@ Features
 
     * CTRL-R to search backwards through history.
     * CTRL-S to search forward through history.
-    * Esc to cancel search (only once).
+    * "!" enters a special search mode, matching only the start of strings.
+    -- Esc to cancel search (only once).
 
     * URL handlers allowing you to enter lines like "http://www.google.com"
       to start your favorite browser on www.google.com.

data/gmrun.1

@@ -45,7 +45,7 @@ The command to run when Ctrl+Enter is pressed with a command entered. The entere
 see /etc/gmrunrc for more info
 .TP
 .B History
-Number of entered commands which should be kept in gmrun's history(~/.gmrun_history). Using the Up and Down arrow keys within the gmrun window will cycle through the history. You can search backwards through the history with Ctrl+R, and forward with Ctrl+S. To cancel a search, hit the \fIESC\fP key. Otherwise, after you have found the history item you wish to run, hit Enter.
+Number of entered commands which should be kept in gmrun's history(~/.gmrun_history). Using the Up and Down arrow keys within the gmrun window will cycle through the history. You can search backwards through the history with Ctrl+R, and forward with Ctrl+S. Hit "!" to enter a special search that matches only the start of strings. To cancel a search, hit the \fIESC\fP key. Otherwise, after you have found the history item you wish to run, hit Enter.
 .TP
 .B ShowLast
 Whether to show the last command as initial text, or an empty textarea (1 or 0).

src/gtkcompletionline.c

@@ -807,18 +807,28 @@ static void search_history (GtkCompletionLine* cl, int next)
          history_current_item = history_search_first_func (cl->hist);
       }
 
+      int search_str_len = 0;
+      int search_match_start = cl->hist_search_match_start;
+      if (search_match_start) {  /* ! */
+         search_str_len = strlen (search_str);
+      }
+
       while (1)
       {
          const char * s = NULL;
          if (history_current_item) {
-            s = strstr (history_current_item, search_str);
+            if (search_match_start) { /* ! */
+               if (strncmp (history_current_item, search_str, search_str_len) == 0) {
+                  s = history_current_item;
+               }
+            } else { /* CTRL-R / CTRL-S */
+               s = strstr (history_current_item, search_str);
+            }
          }
          if (s) {
-            if (strstr (history_current_item, search_str)) {
-               gtk_entry_set_text (GTK_ENTRY(cl), history_current_item);
-               g_signal_emit_by_name (G_OBJECT(cl), "search_letter");
-               return;
-            }
+            gtk_entry_set_text (GTK_ENTRY(cl), history_current_item);
+            g_signal_emit_by_name (G_OBJECT(cl), "search_letter");
+            return;
          }
          history_current_item = history_search_next_func (cl->hist);
          if (history_current_item == NULL) {
@@ -1006,6 +1016,7 @@ on_key_press(GtkCompletionLine *cl, GdkEventKey *event, gpointer data)
             if (cl->hist_search_mode == FALSE) {
                gtk_entry_set_text (GTK_ENTRY (cl), "");
                cl->hist_search_mode = TRUE;
+               cl->hist_search_match_start = FALSE;
                cl->hist_word[0] = 0;
                cl->hist_word_count = 0;
                g_signal_emit_by_name(G_OBJECT(cl), "search_mode");
@@ -1016,6 +1027,22 @@ on_key_press(GtkCompletionLine *cl, GdkEventKey *event, gpointer data)
             return TRUE; /* stop signal emission */
          } else goto ordinary;
 
+      case GDK_KEY_exclam:
+         if (cl->hist_search_mode == FALSE) {
+           const char * entry_text = gtk_entry_get_text (GTK_ENTRY (cl));
+           if (!*entry_text) {
+              history_search_first_func = history_last;
+              history_search_next_func  = history_prev;
+              cl->hist_search_mode = TRUE;
+              cl->hist_search_match_start = TRUE;
+              cl->hist_word[0] = 0;
+              cl->hist_word_count = 0;
+              g_signal_emit_by_name (G_OBJECT(cl), "search_mode");
+              return TRUE; /* stop signal emission */ 
+           }
+         }
+         goto ordinary;
+
       case GDK_KEY_BackSpace:
          if (cl->hist_search_mode == TRUE) {
             if (cl->hist_word[0]) {

src/gtkcompletionline.h

@@ -45,6 +45,7 @@ struct _GtkCompletionLine
  
    HistoryFile * hist;
    gboolean hist_search_mode;
+   gboolean hist_search_match_start;
    char hist_word[1024]; /* history search: word that is being typed */
    int hist_word_count;  /* history search: word that is being typed */