.\" Copyright (c) 1980 The Regents of the University of California.
.\" Redistribution and use in source and binary forms are permitted
.\" provided that the above copyright notice and this paragraph are
.\" duplicated in all such forms and that any documentation,
.\" advertising materials, and other materials related to such
.\" distribution and use acknowledge that the software was developed
.\" by the University of California, Berkeley. The name of the
.\" University may not be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
.\" @(#)getrlimit.2 6.5 (Berkeley) %G%
getrlimit, setrlimit \- control maximum system resource consumption
#include <sys/resource.h>
Limits on the consumption of system resources by the current process
and each process it creates may be obtained with the
parameter is one of the following:
the maximum amount of cpu time (in seconds) to be used by
the largest size, in bytes, of any single file that may be created.
the maximum size, in bytes, of the data segment for a process;
this defines how far a program may extend its break with the
the maximum size, in bytes, of the stack segment for a process;
this defines how far a program's stack segment may be extended.
Stack extension is performed automatically by the system.
the largest size, in bytes, of a
file that may be created.
the maximum size, in bytes, to which a process's resident set size may
grow. This imposes a limit on the amount of physical memory
to be given to a process; if memory is tight, the system will
prefer to take memory from processes that are exceeding their
declared resident set size.
A resource limit is specified as a soft limit and a hard limit. When a
soft limit is exceeded a process may receive a signal (for example, if
the cpu time or file size is exceeded), but it will be allowed to
continue execution until it reaches the hard limit (or modifies
structure is used to specify the hard and soft limits on a resource,
int rlim_cur; /* current (soft) limit */
int rlim_max; /* hard limit */
Only the super-user may raise the maximum limits. Other users
within the range from 0 to
An \*(lqinfinite\*(rq value for a limit is defined as RLIM_INFINITY
(0x7\&f\&f\&f\&f\&f\&f\&f).
Because this information is stored in the per-process information,
this system call must be executed directly by the shell if it
is to affect all future processes created by the shell;
is thus a built-in command to
The system refuses to extend the data or stack space when the limits
would be exceeded in the normal way: a
call fails if the data space limit is reached.
When the stack limit is reached, the process receives
a segmentation fault (SIGSEGV); if this signal is not
caught by a handler using the signal stack, this signal
A file I/O operation that would create a file larger that the process'
soft limit will cause the write to fail and a signal SIGXFSZ to be
generated; this normally terminates the process, but may be caught. When
the soft cpu time limit is exceeded, a signal SIGXCPU is sent to the
A 0 return value indicates that the call succeeded, changing
or returning the resource limit. A return value of \-1 indicates
that an error occurred, and an error code is stored in the global
The address specified for \fIrlp\fP is invalid.
[EPERM] The limit specified to \fIsetrlimit\fP would have
raised the maximum limit value, and the caller is not the super-user.
csh(1), quota(2), sigvec(2), sigstack(2)
projects / unix-history / blob