.\" Copyright (c) 1988, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" the American National Standards Committee X3, on Information .\" Processing Systems. .\" .\" %sccs.include.redist.man% .\" .\" @(#)strtok.3 8.1 (Berkeley) 06/04/93 .\" .Dd .Dt STRTOK 3 .Os BSD 3 .Sh NAME .Nm strtok , .Nm strsep .Nd string token operations .Sh SYNOPSIS .Fd #include .Ft char * .Fn strtok "char *str" "const char *sep" .Sh DESCRIPTION .Bf -symbolic This interface is obsoleted by strsep(3). .Ef .Pp The .Fn strtok function is used to isolate sequential tokens in a null-terminated string, .Fa str . These tokens are separated in the string by at least one of the characters in .Fa sep . The first time that .Fn strtok is called, .Fa str should be specified; subsequent calls, wishing to obtain further tokens from the same string, should pass a null pointer instead. The separator string, .Fa sep , must be supplied each time, and may change between calls. .Pp The .Fn strtok function returns a pointer to the beginning of each subsequent token in the string, after replacing the token itself with a .Dv NUL character. When no more tokens remain, a null pointer is returned. .Sh SEE ALSO .Xr index 3 , .Xr memchr 3 , .Xr rindex 3 , .Xr strchr 3 , .Xr strcspn 3 , .Xr strpbrk 3 , .Xr strrchr 3 , .Xr strsep 3 , .Xr strspn 3 , .Xr strstr 3 .Sh STANDARDS The .Fn strtok function conforms to .St -ansiC . .Sh BUGS There is no way to get tokens from multiple strings simultaneously. .Pp The System V .Fn strtok , if handed a string containing only delimiter characters, will not alter the next starting point, so that a call to .Fn strtok with a different (or empty) delimiter string may return a .Pf non- Dv NULL value. Since this implementation always alters the next starting point, such a sequence of calls would always return .Dv NULL .