util: Add xasprintf portable asprintf variant
Include a portable asprintf variant that works on any C99
conforming platform.
Signed-off-by: Pantelis Antoniou <[email protected]>
Signed-off-by: David Gibson <[email protected]>
diff --git a/util.c b/util.c
index fb124ee..3550f86 100644
--- a/util.c
+++ b/util.c
@@ -46,6 +46,36 @@
return d;
}
+/* based in part from (3) vsnprintf */
+int xasprintf(char **strp, const char *fmt, ...)
+{
+ int n, size = 128; /* start with 128 bytes */
+ char *p;
+ va_list ap;
+
+ /* initial pointer is NULL making the fist realloc to be malloc */
+ p = NULL;
+ while (1) {
+ p = xrealloc(p, size);
+
+ /* Try to print in the allocated space. */
+ va_start(ap, fmt);
+ n = vsnprintf(p, size, fmt, ap);
+ va_end(ap);
+
+ /* If that worked, return the string. */
+ if (n > -1 && n < size)
+ break;
+ /* Else try again with more space. */
+ if (n > -1) /* glibc 2.1 */
+ size = n + 1; /* precisely what is needed */
+ else /* glibc 2.0 */
+ size *= 2; /* twice the old size */
+ }
+ *strp = p;
+ return strlen(p);
+}
+
char *join_path(const char *path, const char *name)
{
int lenp = strlen(path);
