MBTOWC(3) Linux Programmer's Manual MBTOWC(3)NAMEmbtowc - convert a multibyte sequence to a wide character
SYNOPSIS
#include <stdlib.h>
int mbtowc(wchar_t *pwc, const char *s, size_t n);
DESCRIPTION
The main case for this function is when s is not NULL and pwc is not
NULL. In this case, the mbtowc() function inspects at most n bytes of
the multibyte string starting at s, extracts the next complete multi‐
byte character, converts it to a wide character and stores it at *pwc.
It updates an internal shift state known only to the mbtowc() function.
If s does not point to a null byte ('\0'), it returns the number of
bytes that were consumed from s, otherwise it returns 0.
If the n bytes starting at s do not contain a complete multibyte char‐
acter, or if they contain an invalid multibyte sequence, mbtowc()
returns -1. This can happen even if n >= MB_CUR_MAX, if the multibyte
string contains redundant shift sequences.
A different case is when s is not NULL but pwc is NULL. In this case,
the mbtowc() function behaves as above, except that it does not store
the converted wide character in memory.
A third case is when s is NULL. In this case, pwc and n are ignored.
The mbtowc() function resets the shift state, only known to this func‐
tion, to the initial state, and returns nonzero if the encoding has
nontrivial shift state, or zero if the encoding is stateless.
RETURN VALUE
If s is not NULL, the mbtowc() function returns the number of consumed
bytes starting at s, or 0 if s points to a null byte, or -1 upon fail‐
ure.
If s is NULL, the mbtowc() function returns nonzero if the encoding has
nontrivial shift state, or zero if the encoding is stateless.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
┌──────────┬───────────────┬────────────────┐
│Interface │ Attribute │ Value │
├──────────┼───────────────┼────────────────┤
│mbtowc() │ Thread safety │ MT-Unsafe race │
└──────────┴───────────────┴────────────────┘
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
NOTES
The behavior of mbtowc() depends on the LC_CTYPE category of the cur‐
rent locale.
This function is not multithread safe. The function mbrtowc(3) pro‐
vides a better interface to the same functionality.
SEE ALSOMB_CUR_MAX(3), mblen(3), mbrtowc(3), mbstowcs(3), wcstombs(3),
wctomb(3)COLOPHON
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description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2016-10-08 MBTOWC(3)
