1 .\" Copyright (c) 1980, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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 .\" 3. All advertising materials mentioning features or use of this software
13 .\" must display the following acknowledgement:
14 .\" This product includes software developed by the University of
15 .\" California, Berkeley and its contributors.
16 .\" 4. 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 .\" @(#)getrlimit.2 8.1 (Berkeley) 6/4/93
33 .\" $FreeBSD: src/lib/libc/sys/getrlimit.2,v 1.10.2.5 2001/12/14 18:34:00 ru Exp $
41 .Nd control maximum system resource consumption
49 .Fn getrlimit "int resource" "struct rlimit *rlp"
51 .Fn setrlimit "int resource" "const struct rlimit *rlp"
53 Limits on the consumption of system resources by the current process
54 and each process it creates may be obtained with the
56 call, and set with the
62 parameter is one of the following:
63 .Bl -tag -width RLIMIT_FSIZEAA
65 The largest size (in bytes)
67 file that may be created.
69 The maximum amount of cpu time (in seconds) to be used by
72 The maximum size (in bytes) of the data segment for a process;
73 this defines how far a program may extend its break with the
77 The largest size (in bytes) file that may be created.
79 The maximum size (in bytes) which a process may lock into memory
84 The maximum number of open files for this process.
86 The maximum number of simultaneous processes for this user id.
88 The maximum size (in bytes) to which a process's resident set size may
90 This imposes a limit on the amount of physical memory to be given to
91 a process; if memory is tight, the system will prefer to take memory
92 from processes that are exceeding their declared resident set size.
94 The maximum size (in bytes) of the stack segment for a process;
95 this defines how far a program's stack segment may be extended.
96 Stack extension is performed automatically by the system.
98 The maximum size (in bytes) of socket buffer usage for this user.
99 This limits the amount of network memory, and hence the amount of
100 mbufs, that this user may hold at any time.
103 A resource limit is specified as a soft limit and a hard limit. When a
104 soft limit is exceeded a process may receive a signal (for example, if
105 the cpu time or file size is exceeded), but it will be allowed to
106 continue execution until it reaches the hard limit (or modifies
107 its resource limit). The
109 structure is used to specify the hard and soft limits on a resource,
110 .Bd -literal -offset indent
112 rlim_t rlim_cur; /* current (soft) limit */
113 rlim_t rlim_max; /* maximum value for rlim_cur */
117 Only the super-user may raise the maximum limits. Other users
120 within the range from 0 to
122 or (irreversibly) lower
127 value for a limit is defined as
130 Because this information is stored in the per-process information,
131 this system call must be executed directly by the shell if it
132 is to affect all future processes created by the shell;
134 is thus a built-in command to
137 The system refuses to extend the data or stack space when the limits
138 would be exceeded in the normal way: a
140 call fails if the data space limit is reached.
141 When the stack limit is reached, the process receives
144 if this signal is not
145 caught by a handler using the signal stack, this signal
146 will kill the process.
148 A file I/O operation that would create a file larger that the process'
149 soft limit will cause the write to fail and a signal
152 generated; this normally terminates the process, but may be caught. When
153 the soft cpu time limit is exceeded, a signal
166 The address specified for
170 The limit specified to
173 raised the maximum limit value, and the caller is not the super-user.
185 function call appeared in