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All Rights Reserved. .\" Portions Copyright (c) 2003, Sun Microsystems, Inc. All Rights Reserved. .\" Copyright 2014 Garrett D'Amore .\" .TH MBRLEN 3C "February 17, 2023" .SH NAME mbrlen, mbrlen_l \- get number of bytes in a character (restartable) .SH SYNOPSIS .nf #include \fBsize_t\fR \fBmbrlen\fR(\fBconst char *restrict\fR \fIs\fR, \fBsize_t\fR \fIn\fR, \fBmbstate_t *restrict\fR \fIps\fR); .fi .LP .nf #include #include \fBsize_t\fR \fBmbrlen_l\fR(\fBconst char *restrict\fR \fIs\fR, \fBsize_t\fR \fIn\fR, \fBmbstate_t *restrict\fR \fIps\fR, \fBlocale_t\fR \fIloc\fR); .fi .SH DESCRIPTION If \fIs\fR is not a null pointer, \fBmbrlen()\fR and \fBmbrlen_l()\fR determine the number of bytes constituting the character pointed to by \fIs\fR. The call .nf .IP \fBmbrlen\fR(\fIs\fR, \fIn\fR, \fIps\fR); .fi .LP is equivalent to: .nf .IP mbstate_t internal; \fBmbrtowc\fR(NULL, \fIs\fR, \fIn\fR, \fIps\fR != NULL ? \fIps\fR : &internal); .fi .LP If \fIps\fR is a null pointer, the \fBmbrlen()\fR and \fBmbrlen_l()\fR functions use their own internal \fBmbstate_t\fR object, which is initialized at program startup to the initial conversion state. Otherwise, the \fBmbstate_t\fR object pointed to by \fIps\fR is used to completely describe the current conversion state of the associated character sequence. The implementation will behave as if no function defined in the Reference Manual calls \fBmbrlen()\fR. .LP The behavior of \fBmbrlen()\fR is affected by the \fBLC_CTYPE\fR category of the current locale. See \fBenviron\fR(7). The behavior of \fBmbrlen_l()\fR does not use the current environment and instead uses the locale specified by \fBloc\fR. .SH RETURN VALUES The \fBmbrlen()\fR and \fBmbrlen_l()\fR functions return the first of the following that applies: .sp .ne 2 .na \fB\fB0\fR\fR .ad .RS 17n If the next \fIn\fR or fewer bytes complete the character that corresponds to the null wide-character. .RE .sp .ne 2 .na \fB\fBpositive\fR\fR .ad .RS 17n If the next \fIn\fR or fewer bytes complete a valid character; the value returned is the number of bytes that complete the character. .RE .sp .ne 2 .na \fB\fB(size_t)\(mi2\fR\fR .ad .RS 17n If the next \fIn\fR bytes contribute to an incomplete but potentially valid character, and all \fIn\fR bytes have been processed. When \fIn\fR has at least the value of the \fBMB_CUR_MAX\fR macro, this case can only occur if \fIs\fR points at a sequence of redundant shift sequences (for implementations with state-dependent encodings). .RE .sp .ne 2 .na \fB\fB(size_t)\(mi1\fR\fR .ad .RS 17n If an encoding error occurs, in which case the next \fIn\fR or fewer bytes do not contribute to a complete and valid character. In this case, \fBEILSEQ\fR is stored in \fBerrno\fR and the conversion state is undefined. .RE .SH ERRORS The \fBmbrlen()\fR and \fBmbrlen_l()\fR functions may fail if: .sp .ne 2 .na \fB\fBEINVAL\fR\fR .ad .RS 10n The \fIps\fR argument points to an object that contains an invalid conversion state. .RE .sp .ne 2 .na \fB\fBEILSEQ\fR\fR .ad .RS 10n Invalid character sequence is detected. .RE .SH ATTRIBUTES See \fBattributes\fR(7) for descriptions of the following attributes: .TS box; c | c l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE _ Interface Stability See below. _ MT-Level MT-Safe .TE .LP The .B mbrlen() function is Standard. The .B mbrlen_l() function is Uncommitted. .SH SEE ALSO .BR mbrtowc (3C), .BR mbsinit (3C), .BR newlocale (3C), .BR setlocale (3C), .BR attributes (7), .BR environ (7), .BR standards (7) .SH NOTES If \fIps\fR is not a null pointer, \fBmbrlen()\fR uses the \fBmbstate_t\fR object pointed to by \fIps\fR and the function can be used safely in multithreaded applications, as long as \fBsetlocale\fR(3C) is not being called to change the locale or a per-thread locale has been installed on the calling thread with \fBuselocale\fR(3C). If \fIps\fR is a null pointer, \fBmbrlen()\fR uses its internal \fBmbstate_t\fR object and the function is Unsafe in multithreaded applications.