1 files changed, 27 insertions, 0 deletions
diff --git a/src/stdio/vasprintf.c b/src/stdio/vasprintf.c
new file mode 100644
index 0000000..f2bbc7a
--- /dev/null
+++ b/src/stdio/vasprintf.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+#define GUESS 240U
+
+int vasprintf(char **s, const char *fmt, va_list ap)
+{
+	va_list ap2;
+	char *a;
+	int l=GUESS;
+
+	if (!(a=malloc(GUESS))) return -1;
+
+	va_copy(ap2, ap);
+	l=vsnprintf(a, GUESS, fmt, ap2);
+	va_end(ap2);
+
+	if (l<GUESS) {
+		char *b = realloc(a, l+1U);
+		*s = b ? b : a;
+		return l;
+	}
+	free(a);
+	if (l<0 || !(*s=malloc(l+1U))) return -1;
+	return vsnprintf(*s, l+1U, fmt, ap);
+}