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 \0 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. Subsequent 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 \0 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, 4.3BSD, ISO 9899

strtok_r()
    POSIX.1c

SEE ALSO
index(3), memchr(3), rindex(3), strchr(3), strpbrk(3), strsep(3), strspn(3), strstr(3)