+/* utils.h -- utility prototypes
+ */
+
+/* Call malloc(3), exiting on NULL return. */
+void *mh_xmalloc(size_t size);
+
+/* Call realloc(3), exiting on NULL return. */
+void *mh_xrealloc(void *ptr, size_t size);
+
+/* Call calloc(3), exiting on NULL return. */
+void *mh_xcalloc(size_t nelem, size_t elsize);
+
+/* Duplicate a NUL-terminated string, exit on failure. */
+char *mh_xstrdup(const char *src);
+
+/* Call free(3), if ptr isn't NULL. */
+void mh_xfree(void *ptr);
+
+/* Set p to point to newly allocated, uninitialised, memory. */
+#define NEW(p) ((p) = mh_xmalloc(sizeof *(p)))
+
+/* Set p to point to newly allocated, zeroed, memory. */
+#define NEW0(p) ((p) = mh_xcalloc(1, sizeof *(p)))
+
+char *pwd(void);
+char *add(const char *, char *);
+char *addlist(char *, const char *);
+int folder_exists(const char *);
+void create_folder(char *, int, void (*)(int));
+int num_digits(int);
+
+/*
+ * A vector of char array, used to hold a list of string message numbers
+ * or command arguments.
+ */
+
+struct msgs_array {
+ int max, size;
+ char **msgs;
+};
+
+/*
+ * Same as msgs_array, but for a vector of ints
+ */
+
+struct msgnum_array {
+ int max, size;
+ int *msgnums;
+};