STRTOK(3) Linux Programmer's Manual STRTOK(3)
NAME
strtok, strtok_r - extract tokens from strings
SYNOPSIS
#include <string.h>
char *strtok(char *s, const char *delim);
char *strtok_r(char *s, const char *delim, char **ptrptr);
DESCRIPTION
A `token' is a nonempty string of characters not occurring in the string delim, followed by or by a character occurring in delim.
The strtok() function can be used to parse the string s into tokens. The first call to strtok() should have s as its first argument. Subse-
quent calls should have the first argument set to NULL. Each call returns a pointer to the next token, or NULL when no more tokens are
found.
If a token ends with a delimiter, this delimiting character is overwritten with a and a pointer to the next character is saved for the
next call to strtok(). The delimiter string delim may be different for each call.
The strtok_r() function is a reentrant version of the strtok() function, which instead of using its own static buffer, requires a pointer
to a user allocated char*. This pointer, the ptrptr parameter, must be the same while parsing the same string.
BUGS
Never use these functions. If you do, note that:
These functions modify their first argument.
These functions cannot be used on constant strings.
The identity of the delimiting character is lost.
The strtok() function uses a static buffer while parsing, so it's not thread safe. Use strtok_r() if this matters to you.
RETURN VALUE
The strtok() function returns a pointer to the next token, or NULL if there are no more tokens.
CONFORMING TO
strtok()
SVID 3, POSIX, BSD 4.3, ISO 9899
strtok_r()
POSIX.1c
SEE ALSO
index(3), memchr(3), rindex(3), strchr(3), strpbrk(3), strsep(3), strspn(3), strstr(3)
GNU
2000-02-13 STRTOK(3)