Initial Upload

string.c

@@ -0,0 +1,103 @@
+#include "types.h"
+#include "x86.h"
+
+void* memset(void *dst, int c, uint n) {
+    if ((int)dst % 4 == 0 && n % 4 == 0) {
+        c &= 0xFF;
+        stosl(dst, (c << 24) | (c << 16) | (c << 8) | c, n / 4);
+    }
+    else {
+        stosb(dst, c, n);
+    }
+    return dst;
+}
+
+int memcmp(const void *v1, const void *v2, uint n) {
+    const uchar *s1, *s2;
+
+    s1 = v1;
+    s2 = v2;
+    while (n-- > 0) {
+        if (*s1 != *s2) {
+            return *s1 - *s2;
+        }
+        s1++, s2++;
+    }
+
+    return 0;
+}
+
+void* memmove(void *dst, const void *src, uint n) {
+    const char *s;
+    char *d;
+
+    s = src;
+    d = dst;
+    if (s < d && s + n > d) {
+        s += n;
+        d += n;
+        while (n-- > 0) {
+            *--d = *--s;
+        }
+    }
+    else {
+        while (n-- > 0) {
+            *d++ = *s++;
+        }
+    }
+
+    return dst;
+}
+
+// memcpy exists to placate GCC.  Use memmove.
+void* memcpy(void *dst, const void *src, uint n) {
+    return memmove(dst, src, n);
+}
+
+int strncmp(const char *p, const char *q, uint n) {
+    while (n > 0 && *p && *p == *q) {
+        n--, p++, q++;
+    }
+    if (n == 0) {
+        return 0;
+    }
+    return (uchar) * p - (uchar) * q;
+}
+
+char* strncpy(char *s, const char *t, int n) {
+    char *os;
+
+    os = s;
+    while (n-- > 0 && (*s++ = *t++) != 0) {
+        ;
+    }
+    while (n-- > 0) {
+        *s++ = 0;
+    }
+    return os;
+}
+
+// Like strncpy but guaranteed to NUL-terminate.
+char* safestrcpy(char *s, const char *t, int n) {
+    char *os;
+
+    os = s;
+    if (n <= 0) {
+        return os;
+    }
+    while (--n > 0 && (*s++ = *t++) != 0) {
+        ;
+    }
+    *s = 0;
+    return os;
+}
+
+int strlen(const char *s) {
+    int n;
+
+    for (n = 0; s[n]; n++) {
+        ;
+    }
+    return n;
+}
+