draft transfer implementation

deps/asprintf/asprintf.c

@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "asprintf.h"
+
+int vasprintf(char **strp, const char *fmt, va_list ap) {
+	int size, res;
+
+	va_list cp;
+	va_copy(cp, ap);
+	size = vsnprintf(NULL, 0, fmt, cp);
+	va_end(cp);
+	if (size < 0)
+		return -1;
+
+	*strp = (char *)malloc(size + 1);
+	if (*strp == NULL)
+		return -1;
+
+	res = vsnprintf(*strp, size + 1, fmt, ap);
+	if (res < 0) {
+		free(*strp);
+		return -1;
+	}
+
+	return res;
+}
+
+int asprintf(char **s, const char *fmt, ...) {
+	int ret;
+
+	va_list ap;
+	va_start(ap, fmt);
+	ret = vasprintf(s, fmt, ap);
+	va_end(ap);
+	return ret;
+}