Fixed memory leaks resulting from fn_interp_vars et. al.

[pspp-builds.git] / src / data / filename.c

diff --git a/src/data/filename.c b/src/data/filename.c
index 569d185d223a1313e756cb50ac2b7f7563a7bfd8..728585df11d93ab6b810e75a6990c7b833965fab 100644 (file)
--- a/src/data/filename.c
+++ b/src/data/filename.c
@@ -69,69 +69,87 @@ fn_init (void)
 \f
 /* Functions for performing operations on filenames. */
 
-/* Substitutes $variables as defined by GETENV into INPUT and returns
-   a copy of the resultant string.  Supports $var and ${var} syntaxes;
-   $$ substitutes as $. */
-char *
-fn_interp_vars (const char *input, const char *(*getenv) (const char *))
+
+/* Substitutes $variables as defined by GETENV into TARGET.
+   TARGET must be a string containing the text for which substitution 
+   is required.
+   Supports $var and ${var} syntaxes;
+   $$ substitutes as $. 
+*/
+void 
+fn_interp_vars (struct string *target, 
+                  const char *(*getenv) (const char *))
 {
-  struct string output;
+  assert (target);
 
-  if (NULL == strchr (input, '$'))
-    return xstrdup (input);
+  char *input = xmalloc(ds_length(target) + 1);
+  char *s = input;
 
-  ds_init (&output, strlen (input));
+  strcpy(input, ds_c_str(target));
+
+  if (NULL == strchr (ds_c_str(target), '$'))
+    goto done;
+
+  ds_clear(target);
 
   for (;;)
-    switch (*input)
-      {
-      case '\0':
-       return ds_c_str (&output);
+    {
+      switch (*s)
+       {
+       case '\0':
+         goto done ;
        
-      case '$':
-       input++;
-
-       if (*input == '$')
-         {
-           ds_putc (&output, '$');
-           input++;
-         }
-       else
-         {
-           int stop;
-           int start;
-           const char *value;
-
-           start = ds_length (&output);
-
-           if (*input == '(')
-             {
-               stop = ')';
-               input++;
-             }
-           else if (*input == '{')
-             {
-               stop = '}';
-               input++;
-             }
-           else
-             stop = 0;
+       case '$':
+         s++;
 
-           while (*input && *input != stop
-                  && (stop || isalpha ((unsigned char) *input)))
-             ds_putc (&output, *input++);
+         if (*s == '$')
+           {
+             ds_putc (target, '$');
+             s++;
+           }
+         else
+           {
+             int stop;
+             int start;
+             const char *value;
+
+             start = ds_length (target);
+
+             if (*s == '(')
+               {
+                 stop = ')';
+                 s++;
+               }
+             else if (*s == '{')
+               {
+                 stop = '}';
+                 s++;
+               }
+             else
+               stop = 0;
+
+             while (*s && *s != stop
+                    && (stop || isalpha ((unsigned char) *s)))
+               {
+                 ds_putc (target, *s++);
+               }
            
-           value = getenv (ds_c_str (&output) + start);
-           ds_truncate (&output, start);
-           ds_puts (&output, value);
+             value = getenv (ds_c_str (target) + start);
+             ds_truncate (target, start);
+             ds_puts (target, value);
 
-           if (stop && *input == stop)
-             input++;
-         }
+             if (stop && *s == stop)
+               s++;
+           }
 
-      default:
-       ds_putc (&output, *input++);
-      }
+       default:
+         ds_putc (target, *s++);
+       }
+    }
+
+ done:
+  free(input);
+  return;
 }
 
 #ifdef unix
@@ -218,9 +236,14 @@ fn_search_path (const char *basename, const char *path, const char *prepend)
     return fn_tilde_expand (basename);
   
   {
-    char *temp = fn_interp_vars (path, fn_getenv);
-    bp = subst_path = fn_tilde_expand (temp);
-    free (temp);
+    struct string temp;
+    ds_create(&temp, path);
+
+    fn_interp_vars(&temp, fn_getenv);
+
+    bp = subst_path = fn_tilde_expand (ds_c_str(&temp));
+
+    ds_destroy(&temp);
   }
 
   msg (VM (4), _("Searching for `%s'..."), basename);