init commit

src/string/memcmp.c

@@ -0,0 +1,11 @@
+#include <string.h>
+
+int memcmp(const void *vl, const void *vr, size_t n)
+{
+    const unsigned char *l = vl, *r = vr;
+    for (size_t i = 0; i < n; i++) {
+        if (l[i] != r[i])
+            return l[i] - r[i];
+    }
+    return 0;
+}

src/string/memcpy.c

@@ -0,0 +1,10 @@
+#include <string.h>
+
+void *memcpy(void *restrict dest, const void *restrict src, size_t n)
+{
+    unsigned char *d = dest;
+    const unsigned char *s = src;
+    for (size_t i = 0; i < n; i++)
+        d[i] = s[i];
+    return dest;
+}

src/string/memset.c

@@ -0,0 +1,9 @@
+#include <string.h>
+
+void *memset(void *dest, int c, size_t n)
+{
+    unsigned char *d = dest;
+    for (size_t i = 0; i < n; i++)
+        d[i] = (unsigned char)c;
+    return dest;
+}

src/string/strcmp.c

@@ -0,0 +1,7 @@
+#include <string.h>
+
+int strcmp(const char *l, const char *r)
+{
+    while (*l && *l == *r) l++, r++;
+    return *(unsigned char *)l - *(unsigned char *)r;
+}

src/string/strlen.c

@@ -0,0 +1,8 @@
+#include <string.h>
+
+size_t strlen(const char *s)
+{
+    const char *p = s;
+    while (*p) p++;
+    return p - s;
+}