+ char *cp;
+ size_t len1 = 0, len2 = 0;
+
+ if (s1)
+ len1 = strlen (s1);
+ if (s2)
+ len2 = strlen (s2);
+
+ cp = mh_xmalloc (len1 + len2 + 1);
+
+ /* Copy s1 and free it */
+ if (s1) {
+ memcpy (cp, s1, len1);
+ free (s1);
+ }
+
+ /* Copy s2 */
+ if (s2)
+ memcpy (cp + len1, s2, len2);
+
+ /* Now NULL terminate the string */
+ cp[len1 + len2] = '\0';
+
+ return cp;
+}
+
+/*
+** folder_exists
+** Check to see if a folder exists.
+*/
+int
+folder_exists(char *folder)
+{
+ struct stat st;
+ int exists = 0;
+
+ if (stat (folder, &st) == -1) {
+ /*
+ ** The folder either doesn't exist, or we hit an error.
+ ** Either way return a failure.
+ */
+ exists = 0;
+ } else {
+ /* We can see a folder with the right name */
+ exists = 1;
+ }
+
+ return exists;
+}
+
+
+/*
+** create_folder
+** Check to see if a folder exists, if not, prompt the user to create it.
+*/
+void
+create_folder(char *folder, int autocreate, void (*done_callback)(int))
+{
+ struct stat st;
+ extern int errno;
+ char *cp;
+
+ if (stat (folder, &st) == -1) {
+ if (errno != ENOENT)
+ adios (folder, "error on folder");
+ if (autocreate == 0) {
+ /* ask before creating folder */
+ cp = concat ("Create folder \"", folder, "\"? ", NULL);
+ if (!getanswer (cp))
+ done_callback (1);
+ free (cp);
+ } else if (autocreate == -1) {
+ /* do not create, so exit */
+ done_callback (1);
+ }
+ if (!makedir (folder))
+ adios (NULL, "unable to create folder %s", folder);
+ }
+}
+
+/*
+** num_digits
+** Return the number of digits in a nonnegative integer.
+*/
+int
+num_digits (int n)
+{
+ int ndigits = 0;