LXR linux/arch/x86/boot/string.c

   1/* -*- linux-c -*- ------------------------------------------------------- *
   2 *
   3 *   Copyright (C) 1991, 1992 Linus Torvalds
   4 *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5 *
   6 *   This file is part of the Linux kernel, and is made available under
   7 *   the terms of the GNU General Public License version 2.
   8 *
   9 * ----------------------------------------------------------------------- */
  10
  11/*
  12 * Very basic string functions
  13 */
  14
  15#include "boot.h"
  16
  17int strcmp(const char *str1, const char *str2)
  18{
  19        const unsigned char *s1 = (const unsigned char *)str1;
  20        const unsigned char *s2 = (const unsigned char *)str2;
  21        int delta = 0;
  22
  23        while (*s1 || *s2) {
  24                delta = *s2 - *s1;
  25                if (delta)
  26                        return delta;
  27                s1++;
  28                s2++;
  29        }
  30        return 0;
  31}
  32
  33size_t strnlen(const char *s, size_t maxlen)
  34{
  35        const char *es = s;
  36        while (*es && maxlen) {
  37                es++;
  38                maxlen--;
  39        }
  40
  41        return (es - s);
  42}
  43
  44unsigned int atou(const char *s)
  45{
  46        unsigned int i = 0;
  47        while (isdigit(*s))
  48                i = i * 10 + (*s++ - '0');
  49        return i;
  50}
  51