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-rw-r--r--src/string/memcmp.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/src/string/memcmp.c b/src/string/memcmp.c
new file mode 100644
index 00000000..64dcb464
--- /dev/null
+++ b/src/string/memcmp.c
@@ -0,0 +1,34 @@
+#include <string.h>
+#include "nonstd/assert.h"
+
+/** compare memory regions **/
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+ unsigned char *p = (unsigned char*)s1;
+ unsigned char *q = (unsigned char*)s2;
+ size_t i = 0;
+
+ ASSERT_NONNULL(s1);
+ ASSERT_NONNULL(s2);
+
+ for (i = 0; i < n; i++) {
+ if (p[i] != q[i]) {
+ break;
+ }
+ }
+
+ /*
+ RETURN(NEGATIVE, ARGUMENT(s1) is less than ARGUMENT(s2));
+ RETURN(ZERO, ARGUMENT(s1) and ARGUMENT(s2) are equal);
+ RETURN(POSITIVE(), ARGUMENT(s1) is greater than ARGUMENT(s2));
+ */
+ return p[i] - q[i];
+}
+
+/***
+compares the first ARGUMENT(n) bytes of memory at ARGUMENT(s1)
+and ARGUMENT(s2).
+***/
+/*
+STDC(1)
+*/