Fix the -s option and add a search by regular expression syntax

- syntax change:
  - use the -s/... syntax for regular expression search
  - use the -s#... syntax for absolute positioning
  - use the -s...  syntax for prefix search
- clarify the documentation
- ensure that the words array is correctly updated after previous possible
  alterations

2 files changed, 136 insertions, 56 deletions

diff --git a/smenu.1 b/smenu.1
index ad03c4d..3afc26f 100644
--- a/smenu.1
+++ b/smenu.1
@@ -243,22 +243,31 @@ Note that if this mode each column has the same width.
 .IP "\fB-s\fP \fIpattern\fP"
 Pre-Position the cursor to the first word matching the specified pattern.
 
-\fIpattern\fP" can be:
+\fIpattern\fP can be:
 .RS
 .IP * 2
-A \fBnumber\fP giving the initial position of the cursor (counting from
-0). If this number if greater than the number of words, the cursor will
-be set on la last position.
+A "\fB#\fP" immediately followed by a \fBnumber\fP giving the initial
+position of the cursor (counting from 0). If this number if greater than
+the number of words, the cursor will be set on the latest selectable
+position.
 .IP * 2
-The string \fBlast\fP meaning that we want the initial position to be
-on the last word.
+A single "\fB#\fP" or the string \fB#last\fP to also set the initial
+cursor position at the latest selectable word position.
 .IP * 2
 A string starting with a "\fB/\fP" indicating that we want the cursor
-to be set on the first word matching the \fBprefix\fP string following
-the "\fB/\fP" (\fB/Ca\fP will match \fBCancel\fP by example).
+to be set at the position of the first word matching the given regular
+expression.
+.IP * 2
+A \fBprefix\fP string indicating that we want the cursor to be set on the
+first word matching the string given (\fBCa\fP will match \fBCancel\fP
+by example).
 .PP
-Every failure will do nothing, resulting with the cursor set on the
-first word.
+Warning, when searching for a prefix or a regular expression, smenu
+only look for them only after an eventual modification, so per example,
+the command:
+\f(CBsmenu -I/c/x/ -s/c <<< "a b c d"\fP won't find c and put the cursor
+on \fBa\fP but \f(CBsmenu -I/c/x/v -s/c <<< "a b c d"\fP will find it and
+put the cursor on the \fBx\fP substituting the \fBc\fP on screen only
 .RE
 .IP "\fB-m\fP \fImessage\fP"
 Displays a message above the window. Beware, it will truncated if it
diff --git a/smenu.c b/smenu.c
index ca1b3db..e9f043e 100644
--- a/smenu.c
+++ b/smenu.c
@@ -5512,6 +5512,8 @@ main(int argc, char *argv[])
 
     word_a[count].special_level = special_level;
 
+    /* Save the non modified word in .orig if it has been altered */
+    /* """""""""""""""""""""""""""""""""""""""""""""""""""""""""" */
     if (strcmp(word, dest) != 0)
       word_a[count].orig = word;
     else
@@ -5531,6 +5533,33 @@ main(int argc, char *argv[])
     else
       word_a[count].is_last = 0;
 
+    /* Store the new max number of bytes in a word */
+    /* """"""""""""""""""""""""""""""""""""""""""" */
+    if ((size = (int) word_len) > tab_real_max_size)
+      tab_real_max_size = (int) word_len;
+
+    /* Store the new max word width */
+    /* """""""""""""""""""""""""""" */
+    size = (int) mbstowcs(0, dest, 0);
+
+    if ((size = wcswidth((tmpw = mb_strtowcs(dest)), size)) > tab_max_size)
+      tab_max_size = size;
+
+    free(tmpw);
+
+    /* When the visual only flag is set, we keep the unaltered word so */
+    /* that it can be restituted even if its visual and searchable     */
+    /* representation may have been altered by the previous code       */
+    /* """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" */
+    if ((word_a[count].is_selectable & include_visual_only)
+        | ((!word_a[count].is_selectable) & exclude_visual_only))
+    {
+      free(word_a[count].orig);
+      word_a[count].orig = unaltered_word;
+    }
+    else
+      free(unaltered_word);
+
     /* If the word is selectable insert it in the TST tree */
     /* with its associated index in the input stream.      */
     /* """"""""""""""""""""""""""""""""""""""""""""""""""" */
@@ -5562,33 +5591,6 @@ main(int argc, char *argv[])
       free(w);
     }
 
-    /* Store the new max number of bytes in a word */
-    /* """"""""""""""""""""""""""""""""""""""""""" */
-    if ((size = (int) word_len) > tab_real_max_size)
-      tab_real_max_size = (int) word_len;
-
-    /* Store the new max word width */
-    /* """""""""""""""""""""""""""" */
-    size = (int) mbstowcs(0, dest, 0);
-
-    if ((size = wcswidth((tmpw = mb_strtowcs(dest)), size)) > tab_max_size)
-      tab_max_size = size;
-
-    free(tmpw);
-
-    /* When the visual only flag is set, we keep the unaltered word so */
-    /* that it can be restituted even if its visual and searchable     */
-    /* representation may have been altered by the previous code       */
-    /* """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" */
-    if ((word_a[count].is_selectable & include_visual_only)
-        | ((!word_a[count].is_selectable) & exclude_visual_only))
-    {
-      free(word_a[count].orig);
-      word_a[count].orig = unaltered_word;
-    }
-    else
-      free(unaltered_word);
-
     /* One more word... */
     /* """""""""""""""" */
     if (count == limits.words)
@@ -5753,38 +5755,107 @@ main(int argc, char *argv[])
     last_selectable--;
 
   if (pre_selection_index == NULL)
+    /* option -s was not used */
+    /* """""""""""""""""""""" */
     current = first_selectable;
-  else if (strcmp(pre_selection_index, "last") == 0)
-    current = last_selectable;
   else if (*pre_selection_index == '/')
   {
-    wchar_t *w;
+    /* A regular expression is expected */
+    /* """""""""""""""""""""""""""""""" */
+    regex_t re;
+    int index;
 
-    new_current = last_selectable;
-    if (NULL != tst_prefix_search(tst,
-                                  w = mb_strtowcs(pre_selection_index + 1),
-                                  tst_cb_cli))
-      current = new_current;
+    if (regcomp(&re, pre_selection_index + 1, REG_EXTENDED | REG_NOSUB) != 0)
+    {
+      fprintf(stderr, "Invalid regular expression (%s)\n", pre_selection_index);
+
+      exit(EXIT_FAILURE);
+    }
     else
-      current = first_selectable;
-    free(w);
+    {
+      int found = 0;
+      char *word;
+
+      for (index = first_selectable; index <= last_selectable; index++)
+      {
+        if (word_a[index].orig != NULL)
+          word = word_a[index].orig;
+        else
+          word = word_a[index].str;
+
+        if (regexec(&re, word, (size_t) 0, NULL, 0) == 0)
+        {
+          current = index;
+          found = 1;
+          break;
+        }
+      }
+
+      if (!found)
+        current = first_selectable;
+    }
   }
   else if (*pre_selection_index != '\0')
   {
-    current = atoi(pre_selection_index);
-    if (current >= count)
-      current = count - 1;
-    if (!word_a[current].is_selectable)
+    /* A prefix string or an index is expected */
+    /* """"""""""""""""""""""""""""""""""""""" */
+    size_t len;
+    char *ptr = pre_selection_index;
+
+    if (*ptr == '#')
     {
-      if (current > last_selectable)
+      /* An index is expected */
+      /* """""""""""""""""""" */
+      ptr++;
+
+      if (sscanf(ptr, "%d%n", &current, &len) == 1 && len == strlen(ptr))
+      {
+        /* We got an index (numeric value) */
+        /* """"""""""""""""""""""""""""""" */
+        if (current < 0)
+          current = first_selectable;
+
+        if (current >= count)
+          current = count - 1;
+
+        if (!word_a[current].is_selectable)
+        {
+          if (current > last_selectable)
+            current = last_selectable;
+          else if (current < first_selectable)
+            current = first_selectable;
+          else
+            while (current > first_selectable && !word_a[current].is_selectable)
+              current--;
+        }
+      }
+      else if (*ptr == '\0' || strcmp(ptr, "last") == 0)
+        /* We got a special index (empty or last) */
+        /* """""""""""""""""""""""""""""""""""""" */
         current = last_selectable;
-      else if (current < first_selectable)
-        current = first_selectable;
       else
-        while (current > first_selectable && !word_a[current].is_selectable)
-          current--;
+      {
+        fprintf(stderr, "Invalid index (%s)\n", ptr);
+
+        exit(EXIT_FAILURE);
+      }
+    }
+    else
+    {
+      /* A prefix is expected */
+      /* """""""""""""""""""" */
+      wchar_t *w;
+
+      new_current = last_selectable;
+      if (NULL != tst_prefix_search(tst, w = mb_strtowcs(ptr), tst_cb_cli))
+        current = new_current;
+      else
+        current = first_selectable;
+      free(w);
     }
   }
+  else
+    current = first_selectable;
 
   /* We've finished reading from stdin                               */
   /* we will now get the inputs from the controlling terminal if any */