strnend.c

来自「Many C samples. It is a good sample for 」· C语言 代码 · 共 38 行

/*  File   : strnend.c
    Author : Richard A. O'Keefe.
    Updated: 1 June 1984
    Defines: strnend()

    strnend(src, len)
    returns a pointer to just after the end of the string src, which is
    terminated by a NUL character, or by exhaustion of the length bound
    len.  That is, strnend(s,L)-s = strnlen(s,L).  s+strnlen(s,L) could
    of course be used instead, but this is sometimes clearer.
    Beware: the asm version works only if 0 <= len < 65535.
*/

#include "strings.h"

#if	VaxAsm

char *strnend(src, len)
    char *src;
    int len;
    {
	asm("locc $0,8(ap),*4(ap)");
	asm("movl r1,r0");
    }

#else  ~VaxAsm 

char *strnend(src, len)
    register char *src;
    register int len;
    {
	while (--len >= 0 && *src) src++;
	return src;
    }

#endif	VaxAsm