mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-20 11:11:24 +00:00
128 lines
3.7 KiB
Groff
128 lines
3.7 KiB
Groff
.\" 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 April 19, 1994
|
|
.Dt FGETLN 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm fgetln
|
|
.Nd get a line from a stream
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In stdio.h
|
|
.Ft char *
|
|
.Fn fgetln "FILE *stream" "size_t *len"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn fgetln
|
|
function
|
|
returns a pointer to the next line from the stream referenced by
|
|
.Fa stream .
|
|
This line is
|
|
.Em not
|
|
a C string as it does not end with a terminating
|
|
.Dv NUL
|
|
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 fgetln
|
|
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 fgetln
|
|
function
|
|
may also fail and set
|
|
.Va errno
|
|
for any of the errors specified for the routines
|
|
.Xr fflush 3 ,
|
|
.Xr malloc 3 ,
|
|
.Xr read 2 ,
|
|
.Xr stat 2 ,
|
|
or
|
|
.Xr realloc 3 .
|
|
.Sh SEE ALSO
|
|
.Xr ferror 3 ,
|
|
.Xr fgets 3 ,
|
|
.Xr fopen 3 ,
|
|
.Xr putc 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn fgetln
|
|
function first appeared in
|
|
.Bx 4.4 .
|