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diff --git a/man3/mbtowc.3 b/man3/mbtowc.3 new file mode 100644 index 0000000..743e5a7 --- /dev/null +++ b/man3/mbtowc.3 @@ -0,0 +1,151 @@ +'\" t +.\" Copyright (c) Bruno Haible <haible@clisp.cons.org> +.\" +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" +.\" References consulted: +.\" GNU glibc-2 source code and manual +.\" Dinkumware C library reference http://www.dinkumware.com/ +.\" OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html +.\" ISO/IEC 9899:1999 +.\" +.TH mbtowc 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +mbtowc \- convert a multibyte sequence to a wide character +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <stdlib.h> +.PP +.BI "int mbtowc(wchar_t *restrict " pwc ", const char " s "[restrict ." n "], \ +size_t " n ); +.fi +.SH DESCRIPTION +The main case for this function is when +.I s +is not NULL and +.I pwc +is +not NULL. +In this case, the +.BR mbtowc () +function inspects at most +.I n +bytes of the multibyte string starting at +.IR s , +extracts the next complete +multibyte character, converts it to a wide character and stores it at +.IR *pwc . +It updates an internal shift state known only to the +.BR mbtowc () +function. +If +.I s +does not point to a null byte (\[aq]\e0\[aq]), it returns the number +of bytes that were consumed from +.IR s , +otherwise it returns 0. +.PP +If the +.I n +bytes starting at +.I s +do not contain a complete multibyte +character, or if they contain an invalid multibyte sequence, +.BR mbtowc () +returns \-1. +This can happen even if +.I n +>= +.IR MB_CUR_MAX , +if the multibyte string contains redundant shift sequences. +.PP +A different case is when +.I s +is not NULL but +.I pwc +is NULL. +In this case, the +.BR mbtowc () +function behaves as above, except that it does not +store the converted wide character in memory. +.PP +A third case is when +.I s +is NULL. +In this case, +.I pwc +and +.I n +are +ignored. +The +.BR mbtowc () +function +.\" The Dinkumware doc and the Single UNIX specification say this, but +.\" glibc doesn't implement this. +resets the shift state, only known to this function, +to the initial state, and +returns nonzero if the encoding has nontrivial shift state, or zero if the +encoding is stateless. +.SH RETURN VALUE +If +.I s +is not NULL, the +.BR mbtowc () +function returns the number of +consumed bytes starting at +.IR s , +or 0 if +.I s +points to a null byte, +or \-1 upon failure. +.PP +If +.I s +is NULL, the +.BR mbtowc () +function +returns nonzero if the encoding +has nontrivial shift state, or zero if the encoding is stateless. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR mbtowc () +T} Thread safety MT-Unsafe race +.TE +.sp 1 +.SH VERSIONS +This function is not multithread safe. +The function +.BR mbrtowc (3) +provides +a better interface to the same functionality. +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +POSIX.1-2001, C99. +.SH NOTES +The behavior of +.BR mbtowc () +depends on the +.B LC_CTYPE +category of the +current locale. +.SH SEE ALSO +.BR MB_CUR_MAX (3), +.BR mblen (3), +.BR mbrtowc (3), +.BR mbstowcs (3), +.BR wcstombs (3), +.BR wctomb (3) |