STRTOK(3)

NAME
strtok, strtok_r, strsep - get next token from a string

SYNOPSIS

#include <string.h>

char *strtok(char *restrict source, const char *restrict delimiters);

char *strtok_r(char *restrict source, const char *restrict delimiters, char **lasts);

char *strsep(char **source_ptr, const char *delimiters);

DESCRIPTION

The strtok function is used to isolate sequential tokens in a null-terminated string, *source. These tokens are delimited in the string by at least one of the characters in *delimiters. The first time that strtok is called, *source should be specified; subsequent calls, wishing to obtain further tokens from the same string, should pass a null pointer instead. The separator string, *delimiters, must be supplied each time and may change between calls.

The strtok function returns a pointer to the beginning of each subsequent token in the string, after replacing the separator character itself with a null character. When no more tokens remain, a null pointer is returned.

The strtok_r function has the same behavior as strtok, except a pointer to placeholder *lasts must be supplied by the caller.

The strsep function is similar in behavior to strtok, except a pointer to the string pointer must be supplied source_ptr and the function does not skip leading delimiters. When the string starts with a delimiter, the delimiter is changed to the null character and the empty string is returned. Like strtok_r and strtok, the *source_ptr is updated to the next character following the last delimiter found or NULL if the end of string is reached with no more delimiters.

RETURNS

strtok, strtok_r, and strsep all return a pointer to the next token, or NULL if no more tokens can be found. For strsep, a token may be the empty string.

NOTES

strtok is unsafe for multi-threaded applications. strtok_r and strsep are thread-safe and should be used instead.

PORTABILITY

strtok is ANSI C. strtok_r is POSIX. strsep is a BSD extension.

strtok, strtok_r, and strsep require no supporting OS subroutines.

AUTHORS

Steve Chamberlain
    Author.

Roland Pesch
    Author.

Red Hat Support

Jeff Johnston
    Author.

COPYRIGHT

This file documents the ANSI C library.

Copyright (C) 1992, 1993, 1994-2014 Red Hat, Inc.

libc includes software developed by the University of California, Berkeley and its contributors.

libc includes software developed by Martin Jackson, Graham Haley and Steve Chamberlain of Tadpole Technology and released to Cygnus.

libc uses floating-point conversion software developed at AT&T, which includes this copyright information:

The author of this software is David M. Gay.

Copyright (c) 1991 by AT&T.

Permission to use, copy, modify, and distribute this software for any purpose without fee is hereby granted, provided that this entire notice is included in all copies of any software which is or includes a copy or modification of this software and in all copies of the supporting documentation for such software.

THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.

Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, subject to the terms of the GNU General Public License, which includes the provision that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions.