| .\" Copyright (c) Bruno Haible <haible@clisp.cons.org> |
| .\" |
| .\" %%%LICENSE_START(GPLv2+_DOC_ONEPARA) |
| .\" This is free documentation; you can redistribute it and/or |
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| .\" published by the Free Software Foundation; either version 2 of |
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| .\" %%%LICENSE_END |
| .\" |
| .\" 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 MBRLEN 3 2021-03-22 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| mbrlen \- determine number of bytes in next multibyte character |
| .SH SYNOPSIS |
| .nf |
| .B #include <wchar.h> |
| .PP |
| .BI "size_t mbrlen(const char *restrict " s ", size_t " n , |
| .BI " mbstate_t *restrict " ps ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR mbrlen () |
| function inspects at most |
| .I n |
| bytes of the multibyte |
| string starting at |
| .I s |
| and extracts the next complete multibyte character. |
| It updates the shift state |
| .IR *ps . |
| If the multibyte character is not the |
| null wide character, it returns the number of bytes that were consumed from |
| .IR s . |
| If the multibyte character is the null wide character, it resets the |
| shift state |
| .I *ps |
| to the initial state and returns 0. |
| .PP |
| If the |
| .IR n |
| bytes starting at |
| .I s |
| do not contain a complete multibyte |
| character, |
| .BR mbrlen () |
| returns |
| .IR "(size_t)\ \-2" . |
| This can happen even if |
| .I n |
| >= |
| .IR MB_CUR_MAX , |
| if the multibyte string contains redundant shift |
| sequences. |
| .PP |
| If the multibyte string starting at |
| .I s |
| contains an invalid multibyte |
| sequence before the next complete character, |
| .BR mbrlen () |
| returns |
| .IR "(size_t)\ \-1" |
| and sets |
| .I errno |
| to |
| .BR EILSEQ . |
| In this case, |
| the effects on |
| .I *ps |
| are undefined. |
| .PP |
| If |
| .I ps |
| is NULL, a static anonymous state known only to the |
| .BR mbrlen () |
| function is used instead. |
| .SH RETURN VALUE |
| The |
| .BR mbrlen () |
| function returns the number of bytes |
| parsed from the multibyte |
| sequence starting at |
| .IR s , |
| if a non-null wide character was recognized. |
| It returns 0, if a null wide character was recognized. |
| It returns |
| .I "(size_t)\ \-1" |
| and sets |
| .I errno |
| to |
| .BR EILSEQ , |
| if an invalid multibyte sequence was |
| encountered. |
| It returns |
| .IR "(size_t)\ \-2" |
| if it couldn't parse a complete multibyte |
| character, meaning that |
| .I n |
| should be increased. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .ad l |
| .nh |
| .TS |
| allbox; |
| lbx lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR mbrlen () |
| T} Thread safety MT-Unsafe race:mbrlen/!ps |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008, C99. |
| .SH NOTES |
| The behavior of |
| .BR mbrlen () |
| depends on the |
| .B LC_CTYPE |
| category of the |
| current locale. |
| .SH SEE ALSO |
| .BR mbrtowc (3) |