musl/src/string/strsep.c

#define _GNU_SOURCE
#include <string.h>

char *strsep(char **str, const char *sep)
{
	char *s = *str, *end;
	if (!s) return NULL;
	end = s + strcspn(s, sep);
	if (*end) *end++ = 0;
	else end = 0;
	*str = end;
	return s;
}