| .\" Copyright (c) Bruno Haible <haible@clisp.cons.org> |
| .\" |
| .\" This is free documentation; you can redistribute it and/or |
| .\" modify it under the terms of the GNU General Public License as |
| .\" published by the Free Software Foundation; either version 2 of |
| .\" the License, or (at your option) any later version. |
| .\" |
| .\" 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 MBLEN 3 1999-07-25 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| mblen \- determine number of bytes in next multibyte character |
| .SH SYNOPSIS |
| .nf |
| .B #include <stdlib.h> |
| .sp |
| .BI "int mblen(const char *" s ", size_t " n ); |
| .fi |
| .SH DESCRIPTION |
| If \fIs\fP is not a NULL pointer, the \fBmblen\fP() function inspects at most |
| \fIn\fP bytes of the multibyte string starting at \fIs\fP and extracts the |
| next complete multibyte character. It uses a static anonymous shift state only |
| known to the mblen function. If the multibyte character is not the null wide |
| character, it returns the number of bytes that were consumed from \fIs\fP. If |
| the multibyte character is the null wide character, it returns 0. |
| .PP |
| If the \fIn\fP bytes starting at \fIs\fP do not contain a complete multibyte |
| character, \fBmblen\fP() returns \fI-1\fP. This can happen even if |
| \fIn\fP >= \fIMB_CUR_MAX\fP, if the multibyte string contains redundant shift |
| sequences. |
| .PP |
| If the multibyte string starting at \fIs\fP contains an invalid multibyte |
| sequence before the next complete character, \fBmblen\fP() also returns \fI-1\fP. |
| .PP |
| If \fIs\fP is a NULL pointer, the \fBmblen\fP() 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 non-zero if the encoding has non-trivial shift state, or zero if the |
| encoding is stateless. |
| .SH "RETURN VALUE" |
| The \fBmblen\fP() function returns the number of bytes parsed from the multibyte |
| sequence starting at \fIs\fP, if a non-null wide character was recognized. |
| It returns 0, if a null wide character was recognized. It returns \-1, if an |
| invalid multibyte sequence was encountered or if it couldn't parse a complete |
| multibyte character. |
| .SH "CONFORMING TO" |
| ISO/ANSI C, UNIX98 |
| .SH "SEE ALSO" |
| .BR mbrlen (3) |
| .SH NOTES |
| The behaviour of \fBmblen\fP() depends on the LC_CTYPE category of the |
| current locale. |
| .PP |
| The function \fBmbrlen\fP() provides a better interface to the same |
| functionality. |