byte_rchr.c

来自「linux下qmail的源码 本人加了一些注释」· C语言 代码 · 共 24 行

#include "byte.h"

unsigned int byte_rchr(s,n,c)
char *s;
register unsigned int n;
int c;
{
  register char ch;
  register char *t;
  register char *u;

  ch = c;
  t = s;
  u = 0;
  for (;;) {
    if (!n) break; if (*t == ch) u = t; ++t; --n;
    if (!n) break; if (*t == ch) u = t; ++t; --n;
    if (!n) break; if (*t == ch) u = t; ++t; --n;
    if (!n) break; if (*t == ch) u = t; ++t; --n;
  }
  if (!u) u = t;
  return u - s;
}