1.\" $NetBSD: fgetwln.3,v 1.1 2005/05/14 23:51:02 christos Exp $ 2.\" $DragonFly: src/lib/libc/stdio/fgetwln.3,v 1.1 2005/07/25 00:37:41 joerg Exp $ 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)fgetln.3 8.3 (Berkeley) 4/19/94 35.\" $FreeBSD: src/lib/libc/stdio/fgetwln.3,v 1.1 2004/07/16 06:06:09 tjr Exp $ 36.\" 37.Dd July 16, 2004 38.Dt FGETWLN 3 39.Os 40.Sh NAME 41.Nm fgetwln 42.Nd get a line of wide characters from a stream 43.Sh LIBRARY 44.Lb libc 45.Sh SYNOPSIS 46.In stdio.h 47.In wchar.h 48.Ft wchar_t * 49.Fn fgetwln "FILE * restrict stream" "size_t * restrict len" 50.Sh DESCRIPTION 51The 52.Fn fgetwln 53function 54returns a pointer to the next line from the stream referenced by 55.Fa stream . 56This line is 57.Em not 58a standard wide character string as it does not end with a terminating 59null wide character. 60The length of the line, including the final newline, 61is stored in the memory location to which 62.Fa len 63points. 64(Note, however, that if the line is the last 65in a file that does not end in a newline, 66the returned text will not contain a newline.) 67.Sh RETURN VALUES 68Upon successful completion a pointer is returned; 69this pointer becomes invalid after the next 70.Tn I/O 71operation on 72.Fa stream 73(whether successful or not) 74or as soon as the stream is closed. 75Otherwise, 76.Dv NULL 77is returned. 78The 79.Fn fgetwln 80function 81does not distinguish between end-of-file and error; the routines 82.Xr feof 3 83and 84.Xr ferror 3 85must be used 86to determine which occurred. 87If an error occurs, the global variable 88.Va errno 89is set to indicate the error. 90The end-of-file condition is remembered, even on a terminal, and all 91subsequent attempts to read will return 92.Dv NULL 93until the condition is 94cleared with 95.Xr clearerr 3 . 96.Pp 97The text to which the returned pointer points may be modified, 98provided that no changes are made beyond the returned size. 99These changes are lost as soon as the pointer becomes invalid. 100.Sh ERRORS 101.Bl -tag -width Er 102.It Bq Er EBADF 103The argument 104.Fa stream 105is not a stream open for reading. 106.El 107.Pp 108The 109.Fn fgetwln 110function 111may also fail and set 112.Va errno 113for any of the errors specified for the routines 114.Xr mbrtowc 3 , 115.Xr realloc 3 , 116or 117.Xr read 2 . 118.Sh SEE ALSO 119.Xr ferror 3 , 120.Xr fgetln 3 , 121.Xr fgetws 3 , 122.Xr fopen 3 123