newlib-cygwin/newlib/libc/string/strtok.c

91 lines
2.8 KiB
C

/*
FUNCTION
<<strtok>>, <<strtok_r>>, <<strsep>>---get next token from a string
INDEX
strtok
INDEX
strtok_r
INDEX
strsep
SYNOPSIS
#include <string.h>
char *strtok(char *restrict <[source]>,
const char *restrict <[delimiters]>);
char *strtok_r(char *restrict <[source]>,
const char *restrict <[delimiters]>,
char **<[lasts]>);
char *strsep(char **<[source_ptr]>, const char *<[delimiters]>);
DESCRIPTION
The <<strtok>> function is used to isolate sequential tokens in a
null-terminated string, <<*<[source]>>>. These tokens are delimited
in the string by at least one of the characters in <<*<[delimiters]>>>.
The first time that <<strtok>> is called, <<*<[source]>>> should be
specified; subsequent calls, wishing to obtain further tokens from
the same string, should pass a null pointer instead. The separator
string, <<*<[delimiters]>>>, must be supplied each time and may
change between calls.
The <<strtok>> function returns a pointer to the beginning of each
subsequent token in the string, after replacing the separator
character itself with a null character. When no more tokens remain,
a null pointer is returned.
The <<strtok_r>> function has the same behavior as <<strtok>>, except
a pointer to placeholder <<*<[lasts]>>> must be supplied by the caller.
The <<strsep>> function is similar in behavior to <<strtok>>, except
a pointer to the string pointer must be supplied <<<[source_ptr]>>> and
the function does not skip leading delimiters. When the string starts
with a delimiter, the delimiter is changed to the null character and
the empty string is returned. Like <<strtok_r>> and <<strtok>>, the
<<*<[source_ptr]>>> is updated to the next character following the
last delimiter found or NULL if the end of string is reached with
no more delimiters.
RETURNS
<<strtok>>, <<strtok_r>>, and <<strsep>> all return a pointer to the
next token, or <<NULL>> if no more tokens can be found. For
<<strsep>>, a token may be the empty string.
NOTES
<<strtok>> is unsafe for multi-threaded applications. <<strtok_r>>
and <<strsep>> are thread-safe and should be used instead.
PORTABILITY
<<strtok>> is ANSI C.
<<strtok_r>> is POSIX.
<<strsep>> is a BSD extension.
<<strtok>>, <<strtok_r>>, and <<strsep>> require no supporting OS subroutines.
QUICKREF
strtok ansi impure
*/
/* undef STRICT_ANSI so that strtok_r prototype will be defined */
#undef __STRICT_ANSI__
#include <string.h>
#include <stdlib.h>
#include <_ansi.h>
#include <reent.h>
#ifndef _REENT_ONLY
extern char *__strtok_r (char *, const char *, char **, int);
char *
strtok (register char *__restrict s,
register const char *__restrict delim)
{
struct _reent *reent = _REENT;
_REENT_CHECK_MISC(reent);
return __strtok_r (s, delim, &(_REENT_STRTOK_LAST(reent)), 1);
}
#endif