strcmp.c

来自「一个C源代码分析器」· C语言 代码 · 共 44 行

/* Copyright (C) 1991 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <string.h>
#include <memcopy.h>

/* Compare S1 and S2, returning less than, equal to or
   greater than zero if S1 is lexiographically less than,
   equal to or greater than S2.  */
int
DEFUN(strcmp, (p1, p2), CONST char *p1 AND CONST char *p2)
{
  register CONST unsigned char *s1 = (CONST unsigned char *) p1;
  register CONST unsigned char *s2 = (CONST unsigned char *) p2;
  unsigned reg_char c1, c2;

  do
    {
      c1 = (unsigned char) *s1++;
      c2 = (unsigned char) *s2++;
      if (c1 == '\0')
	return c1 - c2;
    }
  while (c1 == c2);

  return c1 - c2;
}