1 files changed, 173 insertions, 0 deletions
diff --git a/lib/string.c b/lib/string.c
new file mode 100644
index 0000000..0e8fbeb
--- /dev/null
+++ b/lib/string.c
@@ -0,0 +1,173 @@
+#include <string.h>
+
+void* memchr(const void* s, int c, size_t n) {
+  unsigned char *p = (unsigned char*) s;
+  while(n--) {
+    if(*p != (unsigned char) c) {
+      p++;
+    } else {
+      return p;
+    }
+  }
+  return 0;
+}
+
+int memcmp(const void* s1, const void* s2, size_t n) {
+  const unsigned char* p1 = (const unsigned char*) s1;
+  const unsigned char* p2 = (const unsigned char*) s2;
+  while(n--) {
+    if(*p1 != *p2) {
+      return *p1 - *p2;
+    } else {
+      p1++, p2++;
+    }
+  }
+  return 0;
+}
+
+void* memcpy(void* dest, const void* src, size_t n) {
+  char *dp = (char*) dest;
+  const char *sp = (const char*) src;
+  while(n--) *dp++ = *sp++;
+  return dest;
+}
+
+void* memmove(void* dest, const void* src, size_t n) {
+  unsigned char tmp[n];
+  memcpy(tmp, src, n);
+  memcpy(dest, tmp, n);
+  return dest;
+}
+
+void* memset(void* s, int c, size_t n) {
+  unsigned char* p = (unsigned char*) s;
+  while(n--) *p++ = (unsigned char) c;
+  return s;
+}
+
+size_t strlen(const char* str) {
+  const char* s;
+  for(s = str; *s; ++s) {}
+  return (s - str);
+}
+
+char* strcat(char* dest, const char* src) {
+  size_t dest_len = strlen(dest);
+  size_t i;
+
+  for(i = 0; src[i] != '\0'; i++) {
+    dest[dest_len + i] = src[i];
+  }
+  dest[dest_len + i] = '\0';
+  return dest;
+}
+
+char* strncat(char* dest, const char* src, size_t n) {
+  size_t dest_len = strlen(dest);
+  size_t i;
+
+  for(i = 0; i < n && src[i] != '\0'; i++) {
+    dest[dest_len + i] = src[i];
+  }
+  dest[dest_len + i] = '\0';
+  return dest;
+}
+
+char* strchr(const char* s, int c) {
+  while(*s != (char) c) {
+    if(!*s++) return 0;
+  }
+  return (char*) s;
+}
+
+char* strrchr(char* s, int c) {
+  char* ret = 0;
+  do {
+    if(*s == (char) c) ret = s;
+  } while(*s++);
+  return ret;
+}
+
+int strcmp(const char* s1, const char* s2) {
+  while(*s1 && (*s1 == *s2)) s1++, s2++;
+  return *(const unsigned char*) s1 - *(const unsigned char*) s2;
+}
+
+int strncmp(const char* s1, const char* s2, size_t n) {
+  while(n--) {
+    if(*s1++ != *s2++) {
+      return *(unsigned char*) (s1 - 1) - *(unsigned char*) (s2 - 1);
+    }
+  }
+  return 0;
+}
+
+char* strcpy(char* dest, const char* src) {
+  char* ret = dest;
+  while(*dest++ = *src++);
+  return ret;
+}
+
+char* strncpy(char* dest, const char* src, size_t n) {
+  char* ret = dest;
+  do {
+    if(!n--) return ret;
+  } while (*dest++ = *src++);
+  while(n--) *dest++ = 0;
+  return ret;
+}
+
+size_t strcspn(const char* s1, const char* s2) {
+  size_t ret = 0;
+  while(*s1) {
+    if(strchr(s2, *s1)) {
+      return ret;
+    } else {
+      s1++, ret++;
+    }
+  }
+  return ret;
+}
+
+size_t strspn(const char* s1, const char* s2) {
+  size_t ret = 0;
+  while(*s1 && strchr(s2, *s1++)) ret++;
+  return ret;
+}
+
+char* strpbrk(const char* s1, const char* s2) {
+  while(*s1) {
+    if(strchr(s2, *s1++)) return (char*) --s1;
+  }
+  return 0;
+}
+
+char* strstr(const char* s1, const char* s2) {
+  size_t n = strlen(s2);
+  while(*s1) {
+    if(!memcmp(s1++, s2, n)) {
+      return (char*) (s1 - 1);
+    }
+  }
+  return 0;
+}
+
+char* strtok(char* str, const char* delim) {
+  static char* p = 0;
+  if(str) {
+    p = str;
+  } else if(!p) {
+    return 0;
+  }
+  str = p + strspn(p, delim);
+  p = str + strcspn(str, delim);
+  if(p == str) return p = 0;
+  p = *p ? *p = 0, p + 1 : 0;
+  return str;
+}
+
+size_t strxfrm(char* dest, const char* src, size_t n) {
+  size_t n2 = strlen(src);
+  if(n > n2) strcpy(dest, src);
+  return n2;
+}