strnrpt.c

来自「Many C samples. It is a good sample for 」· C语言 代码 · 共 34 行

/*  File   : strnrpt.c
    Author : Richard A. O'Keefe.
    Updated: 20 April 1984
    Defines: strnrpt()

    strnrpt(dst, n, src, k) "RePeaTs" the string src into dst  k  times,
    but  will  truncate  the  result at n characters if necessary.  E.g.
    strnrpt(dst, 7, "hack ", 2) will move "hack ha" to dst  WITHOUT  the
    closing  NUL.   The  result  is  the number of characters moved, not
    counting the closing NUL.  Equivalent to strrpt-ing into an infinite
    buffer and then strnmov-ing the result.
*/

#include "strings.h"

int strnrpt(dst, n, src, k)
    register char *dst;
    register int n;
    char *src;
    int k;
    {
	char *save;

	for (save = dst; --k >= 0; dst--) {
	    register char *p;
	    for (p = src; ; ) {
		if (--n < 0) return dst-save;
		if (!(*dst++ = *p++)) break;
	    }
	}
	return dst-save;
    }