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[thirdparty/man-pages.git] / man3 / wcstok.3

.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
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.\" References consulted:
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.\"   ISO/IEC 9899:1999
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.TH WCSTOK 3  1999-07-25 "GNU" "Linux Programmer's Manual"
.SH NAME
wcstok \- split wide-character string into tokens
.SH SYNOPSIS
.nf
.B #include <wchar.h>
.sp
.BI "wchar_t *wcstok(wchar_t *" wcs ", const wchar_t *" delim ", wchar_t **" ptr );
.fi
.SH DESCRIPTION
The \fBwcstok\fP() function is the wide-character equivalent of the
\fBstrtok\fP() function,
with an added argument to make it multithread-safe.
It can be used
to split a wide-character string \fIwcs\fP into tokens, where a token is
defined as a substring not containing any wide-characters from \fIdelim\fP.
.PP
The search starts at \fIwcs\fP, if \fIwcs\fP is not NULL,
or at \fI*ptr\fP, if \fIwcs\fP is NULL.
First, any delimiter wide-characters are skipped, i.e. the
pointer is advanced beyond any wide-characters which occur in \fIdelim\fP.
If the end of the wide-character string is now
reached, \fBwcstok\fP() returns NULL, to indicate that no tokens
were found, and stores an appropriate value in \fI*ptr\fP,
so that subsequent calls to \fBwcstok\fP() will continue to return NULL.
Otherwise, the \fBwcstok\fP() function recognizes the beginning of a token
and returns a pointer to it, but before doing that, it zero-terminates the
token by replacing the next wide-character which occurs in \fIdelim\fP with
a L'\\0' character, and it updates \fI*ptr\fP so that subsequent calls will
continue searching after the end of recognized token.
.SH "RETURN VALUE"
The \fBwcstok\fP() function returns a pointer to the next token,
or NULL if no further token was found.
.SH NOTES
The original \fIwcs\fP wide-character string is destructively modified during
the operation.
.SH EXAMPLE
The following code loops over the tokens contained in a wide-character string.
.sp
.nf
wchar_t *wcs = ...;
wchar_t *token;
wchar_t *state;
for (token = wcstok(wcs, " \\t\\n", &state);
    token != NULL;
    token = wcstok(NULL, " \\t\\n", &state)) {
    ...
}
.fi
.SH "CONFORMING TO"
C99.
.SH "SEE ALSO"
.BR strtok (3),
.BR wcschr (3)