add several useful functions grabbed from madmutt

util.h

@@ -3,6 +3,7 @@
 #ifndef AWESOME_MEM_H
 #define AWESOME_MEM_H
 
+#include <string.h>
 #include "config.h"
 
 #define ssizeof(foo)            (ssize_t)sizeof(foo)
@@ -11,6 +12,7 @@
 #define p_new(type, count)      ((type *)xmalloc(sizeof(type) * (count)))
 #define p_clear(p, count)       ((void)memset((p), 0, sizeof(*(p)) * (count)))
 #define p_realloc(pp, count)    xrealloc((void*)(pp) sizeof(**(pp) * (count)))
+#define p_dup(p, count)         xmemdup((p), sizeof(*(p)) * (count))
 
 #ifdef __GNUC__
 
@@ -63,4 +65,40 @@ xrealloc(void **ptr, ssize_t newsize)
 void eprint(const char *, ...) __attribute__ ((noreturn)) __attribute__ ((format(printf, 1, 2)));
 void spawn(Display *, awesome_config *, const char *);
 
+static inline void *xmemdup(const void *src, ssize_t size)
+{
+    return memcpy(xmalloc(size), src, size);
+}
+
+/** \brief \c NULL resistant strlen.
+ *
+ * Unlinke it's libc sibling, a_strlen returns a ssize_t, and supports its
+ * argument beeing NULL.
+ *
+ * \param[in] s the string.
+ * \return the string length (or 0 if \c s is \c NULL).
+ */
+static inline ssize_t a_strlen(const char *s)
+{
+    return s ? strlen(s) : 0;
+}
+
+
+/** \brief \c NULL resistant strdup.
+ *
+ * the a_strdup() function returns a pointer to a new string, which is a
+ * duplicate of \c s. Memory should be freed using p_delete().
+ *
+ * \warning when s is \c "", it returns NULL !
+ *
+ * \param[in] s the string to duplicate.
+ * \return a pointer to the duplicated string.
+ */
+static inline char *a_strdup(const char *s)
+{
+    ssize_t len = a_strlen(s);
+    return len ? p_dup(s, len + 1) : NULL;
+}
+
+
 #endif