1.\" Copyright (c) 1988, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" %sccs.include.redist.man% 9.\" 10.\" @(#)strtok.3 8.1 (Berkeley) 06/04/93 11.\" 12.Dd 13.Dt STRTOK 3 14.Os BSD 3 15.Sh NAME 16.Nm strtok , 17.Nm strsep 18.Nd string token operations 19.Sh SYNOPSIS 20.Fd #include <string.h> 21.Ft char * 22.Fn strtok "char *str" "const char *sep" 23.Sh DESCRIPTION 24.Bf -symbolic 25This interface is obsoleted by strsep(3). 26.Ef 27.Pp 28The 29.Fn strtok 30function 31is used to isolate sequential tokens in a null-terminated string, 32.Fa str . 33These tokens are separated in the string by at least one of the 34characters in 35.Fa sep . 36The first time that 37.Fn strtok 38is called, 39.Fa str 40should be specified; subsequent calls, wishing to obtain further tokens 41from the same string, should pass a null pointer instead. 42The separator string, 43.Fa sep , 44must be supplied each time, and may change between calls. 45.Pp 46The 47.Fn strtok 48function 49returns a pointer to the beginning of each subsequent token in the string, 50after replacing the token itself with a 51.Dv NUL 52character. 53When no more tokens remain, a null pointer is returned. 54.Sh SEE ALSO 55.Xr index 3 , 56.Xr memchr 3 , 57.Xr rindex 3 , 58.Xr strchr 3 , 59.Xr strcspn 3 , 60.Xr strpbrk 3 , 61.Xr strrchr 3 , 62.Xr strsep 3 , 63.Xr strspn 3 , 64.Xr strstr 3 65.Sh STANDARDS 66The 67.Fn strtok 68function 69conforms to 70.St -ansiC . 71.Sh BUGS 72There is no way to get tokens from multiple strings simultaneously. 73.Pp 74The System V 75.Fn strtok , 76if handed a string containing only delimiter characters, 77will not alter the next starting point, so that a call to 78.Fn strtok 79with a different (or empty) delimiter string 80may return a 81.Pf non- Dv NULL 82value. 83Since this implementation always alters the next starting point, 84such a sequence of calls would always return 85.Dv NULL . 86