av_string: add av_asprintf().

1 files changed, 26 insertions, 0 deletions

diff --git a/libavutil/avstring.c b/libavutil/avstring.c
index b573dd6761..4cebbe04a6 100644
--- a/libavutil/avstring.c
+++ b/libavutil/avstring.c
@@ -91,6 +91,32 @@ size_t av_strlcatf(char *dst, size_t size, const char *fmt, ...)
     return len;
 }
 
+char *av_asprintf(const char *fmt, ...)
+{
+    char *p = NULL;
+    va_list va;
+    int len;
+
+    va_start(va, fmt);
+    len = vsnprintf(NULL, 0, fmt, va);
+    va_end(va);
+    if (len < 0)
+        goto end;
+
+    p = av_malloc(len + 1);
+    if (!p)
+        goto end;
+
+    va_start(va, fmt);
+    len = vsnprintf(p, len + 1, fmt, va);
+    va_end(va);
+    if (len < 0)
+        av_freep(&p);
+
+end:
+    return p;
+}
+
 char *av_d2str(double d)
 {
     char *str= av_malloc(16);