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108 lines
3.3 KiB
Plaintext
108 lines
3.3 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "MBRLEN" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" mbrlen
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.SH NAME
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mbrlen \- get number of bytes in a character (restartable)
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.SH SYNOPSIS
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.LP
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\fB#include <wchar.h>
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.br
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.sp
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size_t mbrlen(const char *restrict\fP \fIs\fP\fB, size_t\fP \fIn\fP\fB,
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.br
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\ \ \ \ \ \ mbstate_t *restrict\fP \fIps\fP\fB);
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.br
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\fP
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.SH DESCRIPTION
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.LP
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If \fIs\fP is not a null pointer, \fImbrlen\fP() shall determine the
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number of bytes constituting the character pointed to by
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\fIs\fP. It shall be equivalent to:
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.sp
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.RS
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.nf
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\fBmbstate_t internal;
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mbrtowc(NULL, s, n, ps != NULL ? ps : &internal);
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\fP
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.fi
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.RE
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.LP
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If \fIps\fP is a null pointer, the \fImbrlen\fP() function shall use
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its own internal \fBmbstate_t\fP object, which is
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initialized at program start-up to the initial conversion state. Otherwise,
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the \fBmbstate_t\fP object pointed to by \fIps\fP
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shall be used to completely describe the current conversion state
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of the associated character sequence. The implementation shall
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behave as if no function defined in this volume of IEEE\ Std\ 1003.1-2001
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calls \fImbrlen\fP().
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.LP
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The behavior of this function is affected by the \fILC_CTYPE\fP category
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of the current locale.
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.SH RETURN VALUE
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.LP
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The \fImbrlen\fP() function shall return the first of the following
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that applies:
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.TP 7
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0
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If the next \fIn\fP or fewer bytes complete the character that corresponds
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to the null wide character.
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.TP 7
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\fIpositive\fP
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If the next \fIn\fP or fewer bytes complete a valid character; the
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value returned shall be the number of bytes that complete
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the character.
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.TP 7
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(\fBsize_t\fP)-2
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If the next \fIn\fP bytes contribute to an incomplete but potentially
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valid character, and all \fIn\fP bytes have been
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processed. When \fIn\fP has at least the value of the {MB_CUR_MAX}
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macro, this case can only occur if \fIs\fP points at a
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sequence of redundant shift sequences (for implementations with state-dependent
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encodings).
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.TP 7
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(\fBsize_t\fP)-1
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If an encoding error occurs, in which case the next \fIn\fP or fewer
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bytes do not contribute to a complete and valid
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character. In this case, [EILSEQ] shall be stored in \fIerrno\fP and
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the conversion state is undefined.
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.sp
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.SH ERRORS
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.LP
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The \fImbrlen\fP() function may fail if:
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.TP 7
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.B EINVAL
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\fIps\fP points to an object that contains an invalid conversion state.
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.TP 7
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.B EILSEQ
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Invalid character sequence is detected.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fImbsinit\fP() , \fImbrtowc\fP() , the Base Definitions volume of
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IEEE\ Std\ 1003.1-2001, \fI<wchar.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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