date and time created 91/03/06 18:09:53 by bostic

[unix-history] / usr / src / lib / libc / string / strsep.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#include <sys/cdefs.h>
#include <string.h>
#include <stdio.h>

#if defined(LIBC_SCCS) && !defined(lint)
static const char sccsid[] = "@(#)strsep.c	5.4 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

/*
 * Get next token from string *stringp, where tokens are nonempty
 * strings separated by characters from delim.  
 *
 * Writes NULs into the string at *stringp to end tokens.
 * delim need not remain constant from call to call.
 * On return, *stringp points past the last NUL written (if there might
 * be further tokens), or is NULL (if there are definitely no more tokens).
 *
 * If *stringp is NULL, strtoken returns NULL.
 */
char *
strsep(stringp, delim)
	register char **stringp;
	register const char *delim;
{
	register char *s;
	register const char *spanp;
	register int c, sc;
	char *tok;

	if ((s = *stringp) == NULL)
		return (NULL);
	for (tok = s;;) {
		c = *s++;
		spanp = delim;
		do {
			if ((sc = *spanp++) == c) {
				if (c == 0)
					s = NULL;
				else
					s[-1] = 0;
				*stringp = s;
				return (tok);
			}
		} while (sc != 0);
	}
	/* NOTREACHED */
}