+ else
+ {
+ free (*to);
+ *to = 0;
+ }
+}
+
+/* Replace any occurrences of the string STR in ARGZ with WITH, reallocating
+ ARGZ as necessary. If REPLACE_COUNT is non-zero, *REPLACE_COUNT will be
+ incremented by number of replacements performed. */
+error_t
+argz_replace (char **argz, size_t *argz_len, const char *str, const char *with,
+ unsigned *replace_count)
+{
+ error_t err = 0;
+
+ if (str && *str)
+ {
+ char *arg = 0;
+ char *src = *argz;
+ size_t src_len = *argz_len;
+ char *dst = 0;
+ size_t dst_len = 0;
+ int delayed_copy = 1; /* True while we've avoided copying anything. */
+ size_t str_len = strlen (str), with_len = strlen (with);
+
+ while (!err && (arg = argz_next (src, src_len, arg)))
+ {
+ char *match = strstr (arg, str);
+ if (match)
+ {
+ char *from = match + str_len;
+ size_t to_len = match - arg;
+ char *to = strndup (arg, to_len);
+
+ while (to && from)
+ {
+ str_append (&to, &to_len, with, with_len);
+ if (to)
+ {
+ match = strstr (from, str);
+ if (match)
+ {
+ str_append (&to, &to_len, from, match - from);
+ from = match + str_len;
+ }
+ else
+ {
+ str_append (&to, &to_len, from, strlen (from));
+ from = 0;
+ }
+ }
+ }
+
+ if (to)
+ {
+ if (delayed_copy)
+ /* We avoided copying SRC to DST until we found a match;
+ now that we've done so, copy everything from the start
+ of SRC. */
+ {
+ if (arg > src)
+ err = argz_append (&dst, &dst_len, src, (arg - src));
+ delayed_copy = 0;
+ }
+ if (! err)
+ err = argz_add (&dst, &dst_len, to);
+ free (to);
+ }
+ else
+ err = ENOMEM;
+
+ if (replace_count)
+ (*replace_count)++;
+ }
+ else if (! delayed_copy)
+ err = argz_add (&dst, &dst_len, arg);
+ }
+
+ if (! err)
+ {
+ if (! delayed_copy)
+ /* We never found any instances of str. */
+ {
+ free (src);
+ *argz = dst;
+ *argz_len = dst_len;
+ }
+ }
+ else if (dst_len > 0)
+ free (dst);
+ }
+
+ return err;