1 files changed, 40 insertions, 0 deletions
diff --git a/src/string/strncat.c b/src/string/strncat.c
new file mode 100644
index 00000000..34800069
--- /dev/null
+++ b/src/string/strncat.c
@@ -0,0 +1,40 @@
+#include <string.h>
+#include "nonstd/assert.h"
+
+/** concatenate bounded string **/
+char * strncat(char * restrict s1, const char * restrict s2, size_t n)
+{
+	char *append = NULL;
+	size_t i;
+
+	ASSERT_NONNULL(s1);
+	ASSERT_NONNULL(s2);
+	ASSERT_NOOVERLAP(s1, s2, strlen(s1) + strlen(s2));
+
+	append = s1 + strlen(s1);
+
+	for (i = 0; i < n; i++) {
+		append[i] = s2[i];
+		if (append[i] == '\0') {
+			break;
+		}
+	}
+
+	if (append[i - 1] != '\0') {
+		append[i] = '\0';
+	}
+
+	return s1;
+}
+
+/***
+appends a copy of the frist ARGUMENT(n) bytes of the string
+at ARGUMENT(s2) to the end of the string at ARGUMENT(s1). The first byte of ARGUMENT(s2) will
+overwrite the terminating null character of ARGUMENT(s1). No characters after the
+first CHAR(\0) will be copied. The resulting string will always be null
+terminated.
+***/
+/*
+	RETURN_ALWAYS(ARGUMENT(s1));
+STDC(1)
+*/