/* nextok.c	Mark W. Renton, MACROSTAFF, renton@pmel.noaa.gov, May 1995

"nextok" is exactly like strtok, except that it allows empty values.

 example:  ",2,,4,"  delimited by  ","  has 5 values (there are 4 commas),

 of which the 1st, 3rd, and 5th are zero-length non-NULL strings.
*/

#include <stddef.h>
#include <string.h>

char *nextok(s,delim)
	char *s, *delim;
{
	char *token;
	static char *last, *end;

	if ( s!=NULL ) {
		end = s + strlen(s) + 1;
	} else {
		if ( (s=last)==NULL )  return NULL;
	}

	if ( s==end ) { last=NULL; return NULL; } ;

	token = s;
	s += strcspn(s,",");
	*s++ = '\0' ;
	last = s;
	return token;
}