Use GNU macro (v)asprintf only if _GNU_SOURCE is defined

1 files changed, 38 insertions, 0 deletions

diff --git a/src/shared.c b/src/shared.c
index 2beaeb8..2f6dd5b 100644
--- a/src/shared.c
+++ b/src/shared.c
@@ -34,3 +34,41 @@ void* xreallocarray(void *ptr, size_t nmemb, size_t size) {
 
     return mem;
 }
+
+#if !defined _GNU_SOURCE
+
+int vasprintf(char **str, const char *format, va_list ap) {
+    va_list ap2;
+    int length, ret;
+
+    va_copy(ap2, ap);
+    if((length = vsnprintf(NULL, 0, format, ap2)) < 0)
+        return -1;
+    length++; // + 1 because sprintf does not count the null byte
+    va_end(ap2);
+
+    char *temp = reallocarray(*str, length, sizeof(char));
+    if(temp == NULL)
+        return -1;
+
+    if((ret = vsnprintf(temp, length, format, ap)) < 0) {
+        free(temp);
+        return -1;
+    } else {
+        *str = temp;
+    }
+    
+    return ret;
+}
+
+int asprintf(char **str, const char *format, ...) {
+    va_list ap;
+
+    va_start(ap, format);
+    int ret = vasprintf(str, format, ap);
+    va_end(ap);
+    
+    return ret;
+}
+
+#endif
\ No newline at end of file