Add permutate_all (and support functions).

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@18126 ec53bebd-3082-4978-b11e-865c3cabbd6b

appl/gssmask/common.c

@@ -49,3 +49,49 @@ store_string(krb5_storage *sp, const char *str)
     return 0;
 }
 
+static void
+add_list(char ****list, size_t *listlen, char **str, size_t len)
+{
+    size_t i;
+    *list = erealloc(*list, sizeof(**list) * (*listlen + 1));
+
+    (*list)[*listlen] = ecalloc(len, sizeof(str)/sizeof(str[0]));
+    for (i = 0; i < len; i++)
+	(*list)[*listlen][i] = str[i];
+    (*listlen)++;
+}
+
+static void
+permute(char ****list, size_t *listlen, 
+	char **str, const int start, const int len) 
+{
+    int i, j;
+
+#define SWAP(s,i,j) { char *t = str[i]; str[i] = str[j]; str[j] = t; }
+
+    for (i = start; i < len - 1; i++) {
+	for (j = i+1; j < len; j++) {
+	    SWAP(str,i,j);
+	    permute(list, listlen, str, i+1, len);
+	    SWAP(str,i,j);
+	}
+    }
+    add_list(list, listlen, str, len);
+}
+
+char ***
+permutate_all(struct getarg_strings *strings, size_t *size)
+{
+    char **list, ***all = NULL;
+    int i;
+
+    *size = 0;
+
+    list = ecalloc(strings->num_strings, sizeof(*list));
+    for (i = 0; i < strings->num_strings; i++)
+	list[i] = strings->strings[i];
+
+    permute(&all, size, list, 0, strings->num_strings);
+    free(list);
+    return all;
+}