util: implement xstrcat

1 files changed, 16 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..4863e29
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <util.h>
+
+void
+xstrcat(char *s1, char *s2)
+{
+  size_t a = strlen(s1);
+  size_t b = strlen(s2);
+  size_t size_ab = a + b + 1;
+
+  s1 = realloc(s1, size_ab);
+
+  memcpy(s1 + a, s2, b + 1);
+}