Merge pull request #117 from gbowne1/klibc-strncpy

[klibc] implment strncpy function

klibc/include/string.h

@@ -10,5 +10,6 @@ extern void* memset(void* dst, int c, size_t n);
 
 extern size_t strlen(const char *s);
 extern int strcmp(const char *s1, const char *s2);
+extern char *strncpy(char *dst, const char *src, size_t n);
 
 #endif  // CLASSICOS_KLIBC_STRING_H

klibc/src/string.c

@@ -105,3 +105,19 @@ int strcmp(const char* s1, const char* s2) {
 
     return d;
 }
+
+char *strncpy(char *dst, const char *src, size_t n) {
+    char *q = dst;
+    const char *p = src;
+    char ch;
+
+    while (n) {
+        n--;
+        *q++ = ch = *p++;
+        if (!ch) break;
+    }
+
+    memset(q, 0, n);
+
+    return dst;
+}