Add fgetwln(), a wide character version of fgetln().

1 files changed, 120 insertions, 0 deletions

diff --git a/lib/libc/stdio/fgetwln.3 b/lib/libc/stdio/fgetwln.3
new file mode 100644
index 0000000..282b03a
--- /dev/null
+++ b/lib/libc/stdio/fgetwln.3
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+.\" Copyright (c) 1990, 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     @(#)fgetln.3	8.3 (Berkeley) 4/19/94
+.\" $FreeBSD$
+.\"
+.Dd July 16, 2004
+.Dt FGETWLN 3
+.Os
+.Sh NAME
+.Nm fgetln
+.Nd get a line of wide characters from a stream
+.Sh LIBRARY
+.Lb libc
+.Sh SYNOPSIS
+.In stdio.h
+.In wchar.h
+.Ft wchar_t *
+.Fn fgetwln "FILE * restrict stream" "size_t * restrict len"
+.Sh DESCRIPTION
+The
+.Fn fgetwln
+function
+returns a pointer to the next line from the stream referenced by
+.Fa stream .
+This line is
+.Em not
+a standard wide character string as it does not end with a terminating
+null wide character.
+The length of the line, including the final newline,
+is stored in the memory location to which
+.Fa len
+points.
+(Note, however, that if the line is the last
+in a file that does not end in a newline,
+the returned text will not contain a newline.)
+.Sh RETURN VALUES
+Upon successful completion a pointer is returned;
+this pointer becomes invalid after the next
+.Tn I/O
+operation on
+.Fa stream
+(whether successful or not)
+or as soon as the stream is closed.
+Otherwise,
+.Dv NULL
+is returned.
+The
+.Fn fgetwln
+function
+does not distinguish between end-of-file and error; the routines
+.Xr feof 3
+and
+.Xr ferror 3
+must be used
+to determine which occurred.
+If an error occurs, the global variable
+.Va errno
+is set to indicate the error.
+The end-of-file condition is remembered, even on a terminal, and all
+subsequent attempts to read will return
+.Dv NULL
+until the condition is
+cleared with
+.Xr clearerr 3 .
+.Pp
+The text to which the returned pointer points may be modified,
+provided that no changes are made beyond the returned size.
+These changes are lost as soon as the pointer becomes invalid.
+.Sh ERRORS
+.Bl -tag -width Er
+.It Bq Er EBADF
+The argument
+.Fa stream
+is not a stream open for reading.
+.El
+.Pp
+The
+.Fn fgetwln
+function
+may also fail and set
+.Va errno
+for any of the errors specified for the routines
+.Xr mbrtowc 3 ,
+.Xr realloc 3 ,
+or
+.Xr read 2 .
+.Sh SEE ALSO
+.Xr ferror 3 ,
+.Xr fgetln 3 ,
+.Xr fgetws 3 ,
+.Xr fopen 3