NetBSD/usr.sbin/sup/source/skipto.c

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1993-05-21 18:52:16 +04:00
/*
* Copyright (c) 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the rights
* to redistribute these changes.
*/
/************************************************************************
* skipover and skipto -- skip over characters in string
*
* Usage: p = skipto (string,charset);
* p = skipover (string,charset);
*
* char *p,*charset,*string;
*
* Skipto returns a pointer to the first character in string which
* is in the string charset; it "skips until" a character in charset.
* Skipover returns a pointer to the first character in string which
* is not in the string charset; it "skips over" characters in charset.
************************************************************************
* HISTORY
* 26-Jun-81 David Smith (drs) at Carnegie-Mellon University
* Skipover, skipto rewritten to avoid inner loop at expense of space.
*
* 20-Nov-79 Steven Shafer (sas) at Carnegie-Mellon University
* Skipover, skipto adapted for VAX from skip() and skipx() on the PDP-11
* (from Ken Greer). The names are more mnemonic.
*
* Sindex adapted for VAX from indexs() on the PDP-11 (thanx to Ralph
* Guggenheim). The name has changed to be more like the index()
* and rindex() functions from Bell Labs; the return value (pointer
* rather than integer) has changed partly for the same reason,
* and partly due to popular usage of this function.
*/
static unsigned char tab[256] = {
0};
char *skipto (string,charset)
unsigned char *string, *charset;
{
register unsigned char *setp,*strp;
tab[0] = 1; /* Stop on a null, too. */
for (setp=charset; *setp; setp++) tab[*setp]=1;
for (strp=string; tab[*strp]==0; strp++) ;
for (setp=charset; *setp; setp++) tab[*setp]=0;
return ((char *)strp);
}
char *skipover (string,charset)
unsigned char *string, *charset;
{
register unsigned char *setp,*strp;
tab[0] = 0; /* Do not skip over nulls. */
for (setp=charset; *setp; setp++) tab[*setp]=1;
for (strp=string; tab[*strp]; strp++) ;
for (setp=charset; *setp; setp++) tab[*setp]=0;
return ((char *)strp);
}