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Diffstat (limited to 'man/man3/fwide.3')
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diff --git a/man/man3/fwide.3 b/man/man3/fwide.3 new file mode 100644 index 000000000..006520aae --- /dev/null +++ b/man/man3/fwide.3 @@ -0,0 +1,92 @@ +.\" 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 fwide 3 (date) "Linux man-pages (unreleased)" +.SH NAME +fwide \- set and determine the orientation of a FILE stream +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <wchar.h> +.P +.BI "int fwide(FILE *" stream ", int " mode ); +.fi +.P +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR fwide (): +.nf + _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE + || _POSIX_C_SOURCE >= 200112L +.fi +.SH DESCRIPTION +When \fImode\fP is zero, the +.BR fwide () +function determines the current +orientation of \fIstream\fP. +It returns a positive value if \fIstream\fP is +wide-character oriented, that is, if wide-character I/O is permitted but char +I/O is disallowed. +It returns a negative value if \fIstream\fP is byte oriented\[em]that is, +if char I/O is permitted but wide-character I/O is disallowed. +It +returns zero if \fIstream\fP has no orientation yet; in this case the next +I/O operation might change the orientation (to byte oriented if it is a char +I/O operation, or to wide-character oriented if it is a wide-character I/O +operation). +.P +Once a stream has an orientation, it cannot be changed and persists until +the stream is closed. +.P +When \fImode\fP is nonzero, the +.BR fwide () +function first attempts to set +\fIstream\fP's orientation (to wide-character oriented +if \fImode\fP is greater than 0, or +to byte oriented if \fImode\fP is less than 0). +It then returns a value denoting the +current orientation, as above. +.SH RETURN VALUE +The +.BR fwide () +function returns the stream's orientation, after possibly +changing it. +A positive return value means wide-character oriented. +A negative return value means byte oriented. +A return value of zero means undecided. +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +POSIX.1-2001, C99. +.SH NOTES +Wide-character output to a byte oriented stream can be performed through the +.BR fprintf (3) +function with the +.B %lc +and +.B %ls +directives. +.P +Char oriented output to a wide-character oriented stream can be performed +through the +.BR fwprintf (3) +function with the +.B %c +and +.B %s +directives. +.SH SEE ALSO +.BR fprintf (3), +.BR fwprintf (3) |