1 .\" Copyright (c) 1990, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" This code is derived from software contributed to Berkeley by
5 .\" Chris Torek and the American National Standards Committee X3,
6 .\" on Information Processing Systems.
8 .\" Redistribution and use in source and binary forms, with or without
9 .\" modification, are permitted provided that the following conditions
11 .\" 1. Redistributions of source code must retain the above copyright
12 .\" notice, this list of conditions and the following disclaimer.
13 .\" 2. Redistributions in binary form must reproduce the above copyright
14 .\" notice, this list of conditions and the following disclaimer in the
15 .\" documentation and/or other materials provided with the distribution.
16 .\" 3. Neither the name of the University nor the names of its contributors
17 .\" may be used to endorse or promote products derived from this software
18 .\" without specific prior written permission.
20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)fgets.3 8.1 (Berkeley) 6/4/93
33 .\" $FreeBSD: src/lib/libc/stdio/fgets.3,v 1.22 2009/02/28 06:00:58 das Exp $
40 .Nd get a line from a stream
49 This interface is made obsolete by
54 .Sx SECURITY CONSIDERATIONS
69 except that the newline character (if any) is not stored in the string.
70 It is the caller's responsibility to ensure that the input line,
71 if any, is sufficiently short to fit in the string.
73 Upon successful completion,
76 a pointer to the string.
77 If end-of-file occurs before any characters are read,
80 and the buffer contents remain unchanged.
84 and the buffer contents are indeterminate.
88 does not distinguish between end-of-file and error, and callers must use
92 to determine which occurred.
98 is not a readable stream.
103 function may also fail and set
105 for any of the errors specified for the routine
107 .Sh SECURITY CONSIDERATIONS
110 function cannot be used securely.
111 Because of its lack of bounds checking,
112 and the inability for the calling program
113 to reliably determine the length of the next incoming line,
114 the use of this function enables malicious users
115 to arbitrarily change a running program's functionality through
116 a buffer overflow attack.
117 It is strongly suggested that the
121 functions be used in all cases.