strpack.c

来自「Many C samples. It is a good sample for 」· C语言 代码 · 共 40 行

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

    strpack(dst, src, set, c)
    copies characters from src to dst, stopping when it finds a NUL.  If
    c is NUL, characters in set are not copied to dst.  If c is not NUL,
    sequences of characters from set are copied as a single c.
    strpack(d, s, " \t", ' ') can be used to compress white space,
    strpack(d, s, " \t", NUL) to eliminate it.  To translate  characters
    in  set to c without compressing runs, see strtrans(). The result is
    the address of the NUL byte now terminating dst.  Note that dst  may
    safely be the same as src.
*/

#include "strings.h"
#include "_str2set.h"

char *strpack(dst, src, set, c)
    register _char_ *dst, *src;
    char *set;
    register int c;
    {
	register int chr;

	_str2set(set);
	while (chr = *src++) {
	    if (_set_vec[chr] == _set_ctr) {
		while ((chr = *src++) && _set_vec[chr] == _set_ctr) ;
		if (c) *dst++ = c;	/* 1. If you don't want trailing */
		if (!chr) break;	/* 2. things turned into "c", swap */
	    }				/* lines 1 and 2. */
	    *dst++ = chr;
	}
	*dst = 0;
	return dst;
    }