mirror of https://github.com/mkerrisk/man-pages
84 lines
2.6 KiB
Groff
84 lines
2.6 KiB
Groff
.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
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.\"
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.\" This is free documentation; you can redistribute it and/or
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.\" modify it under the terms of the GNU General Public License as
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.\" published by the Free Software Foundation; either version 2 of
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.\" the License, or (at your option) any later version.
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.\"
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.\" References consulted:
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.\" GNU glibc-2 source code and manual
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.\" Dinkumware C library reference http://www.dinkumware.com/
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.\" OpenGroup's Single Unix specification http://www.UNIX-systems.org/online.html
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.\" ISO/IEC 9899:1999
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.\"
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.TH WCSTOMBS 3 1999-07-25 "GNU" "Linux Programmer's Manual"
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.SH NAME
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wcstombs \- convert a wide-character string to a multibyte string
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.SH SYNOPSIS
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.nf
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.B #include <stdlib.h>
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.sp
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.BI "size_t wcstombs(char *" dest ", const wchar_t *" src ", size_t " n );
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.fi
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.SH DESCRIPTION
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If \fIdest\fP is not a NULL pointer, the
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.BR wcstombs ()
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function converts
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the wide-character string \fIsrc\fP to a multibyte string starting at
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\fIdest\fP.
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At most \fIn\fP bytes are written to \fIdest\fP.
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The conversion
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starts in the initial state.
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The conversion can stop for three reasons:
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.PP
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1. A wide character has been encountered that can not be represented as a
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multibyte sequence (according to the current locale).
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In this case
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.I (size_t)\ \-1
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is returned.
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.PP
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2. The length limit forces a stop.
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In this case the number of bytes written to
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\fIdest\fP is returned, but the shift state at this point is lost.
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.PP
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3. The wide-character string has been completely converted, including the
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terminating L\(aq\\0\(aq.
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In this case the conversion ends in the initial state.
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The number of bytes written to \fIdest\fP,
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excluding the terminating \(aq\\0\(aq byte, is returned.
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.PP
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The programmer must ensure that there is room for at least \fIn\fP bytes
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at \fIdest\fP.
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.PP
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If \fIdest\fP is NULL, \fIn\fP is ignored, and the conversion proceeds as
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above, except that the converted bytes are not written out to memory,
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and that no length limit exists.
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.PP
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In order to avoid the case 2 above, the programmer should make sure \fIn\fP
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is greater or equal to \fIwcstombs(NULL,src,0)+1\fP.
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.SH "RETURN VALUE"
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The
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.BR wcstombs ()
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function returns the number of bytes that make up the
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converted part of multibyte sequence, not including the terminating null byte.
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If a wide character was encountered which could not be
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converted,
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.I (size_t)\ \-1
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is returned.
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.SH "CONFORMING TO"
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C99.
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.SH NOTES
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The behavior of
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.BR wcstombs ()
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depends on the
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.B LC_CTYPE
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category of the
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current locale.
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.PP
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The function
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.BR wcsrtombs (3)
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provides a thread safe interface to
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the same functionality.
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.SH "SEE ALSO"
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.BR wcsrtombs (3)
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