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strtok(3) [freebsd man page]

STRTOK(3)						   BSD Library Functions Manual 						 STRTOK(3)

strtok, strtok_r -- string tokens LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <string.h> char * strtok(char *str, const char *sep); char * strtok_r(char *str, const char *sep, char **last); DESCRIPTION
This interface is obsoleted by strsep(3). The strtok() function is used to isolate sequential tokens in a null-terminated string, str. These tokens are separated in the string by at least one of the characters in sep. The first time that strtok() is called, str should be specified; subsequent calls, wishing to obtain further tokens from the same string, should pass a null pointer instead. The separator string, sep, must be supplied each time, and may change between calls. The implementation will behave as if no library function calls strtok(). The strtok_r() function is a reentrant version of strtok(). The context pointer last must be provided on each call. The strtok_r() function may also be used to nest two parsing loops within one another, as long as separate context pointers are used. The strtok() and strtok_r() functions return a pointer to the beginning of each subsequent token in the string, after replacing the token itself with a NUL character. When no more tokens remain, a null pointer is returned. EXAMPLES
The following uses strtok_r() to parse two strings using separate contexts: char test[80], blah[80]; char *sep = "\/:;=-"; char *word, *phrase, *brkt, *brkb; strcpy(test, "This;is.a:test:of=the/string\tokenizer-function."); for (word = strtok_r(test, sep, &brkt); word; word = strtok_r(NULL, sep, &brkt)) { strcpy(blah, "blah:blat:blab:blag"); for (phrase = strtok_r(blah, sep, &brkb); phrase; phrase = strtok_r(NULL, sep, &brkb)) { printf("So far we're at %s:%s ", word, phrase); } } SEE ALSO
memchr(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3), strspn(3), strstr(3), wcstok(3) STANDARDS
The strtok() function conforms to ISO/IEC 9899:1990 (``ISO C90''). AUTHORS
Wes Peters <>, Softweyr LLC Based on the FreeBSD 3.0 implementation. BUGS
The System V strtok(), if handed a string containing only delimiter characters, will not alter the next starting point, so that a call to strtok() with a different (or empty) delimiter string may return a non-NULL value. Since this implementation always alters the next starting point, such a sequence of calls would always return NULL. BSD
November 27, 1998 BSD

Check Out this Related Man Page

STRTOK(3)						     Linux Programmer's Manual							 STRTOK(3)

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)

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