1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)fgetln.3 8.3 (Berkeley) 4/19/94 29.\" $FreeBSD: src/lib/libc/stdio/fgetln.3,v 1.10 2009/02/28 06:00:58 das Exp $ 30.\" $DragonFly: src/lib/libc/stdio/fgetln.3,v 1.2 2003/06/17 04:26:45 dillon Exp $ 31.\" 32.Dd April 19, 1994 33.Dt FGETLN 3 34.Os 35.Sh NAME 36.Nm fgetln 37.Nd get a line from a stream 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In stdio.h 42.Ft char * 43.Fn fgetln "FILE *stream" "size_t *len" 44.Sh DESCRIPTION 45The 46.Fn fgetln 47function 48returns a pointer to the next line from the stream referenced by 49.Fa stream . 50This line is 51.Em not 52a C string as it does not end with a terminating 53.Dv NUL 54character. 55The length of the line, including the final newline, 56is stored in the memory location to which 57.Fa len 58points. 59(Note, however, that if the line is the last 60in a file that does not end in a newline, 61the returned text will not contain a newline.) 62.Sh RETURN VALUES 63Upon successful completion a pointer is returned; 64this pointer becomes invalid after the next 65.Tn I/O 66operation on 67.Fa stream 68(whether successful or not) 69or as soon as the stream is closed. 70Otherwise, 71.Dv NULL 72is returned. 73The 74.Fn fgetln 75function 76does not distinguish between end-of-file and error; the routines 77.Xr feof 3 78and 79.Xr ferror 3 80must be used 81to determine which occurred. 82If an error occurs, the global variable 83.Va errno 84is set to indicate the error. 85The end-of-file condition is remembered, even on a terminal, and all 86subsequent attempts to read will return 87.Dv NULL 88until the condition is 89cleared with 90.Xr clearerr 3 . 91.Pp 92The text to which the returned pointer points may be modified, 93provided that no changes are made beyond the returned size. 94These changes are lost as soon as the pointer becomes invalid. 95.Sh ERRORS 96.Bl -tag -width Er 97.It Bq Er EBADF 98The argument 99.Fa stream 100is not a stream open for reading. 101.El 102.Pp 103The 104.Fn fgetln 105function 106may also fail and set 107.Va errno 108for any of the errors specified for the routines 109.Xr fflush 3 , 110.Xr malloc 3 , 111.Xr read 2 , 112.Xr stat 2 , 113or 114.Xr realloc 3 . 115.Sh SEE ALSO 116.Xr ferror 3 , 117.Xr fgets 3 , 118.Xr fgetwln 3 , 119.Xr fopen 3 , 120.Xr getline 3 , 121.Xr putc 3 122.Sh HISTORY 123The 124.Fn fgetln 125function first appeared in 126.Bx 4.4 . 127