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 works the same as the
strtok() function,
but instead of using a static buffer it uses a pointer to a user allocated
char* pointer. 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.
The identity of the delimiting character is lost.
These functions cannot be used on constant strings.
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.
- 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)
