1GETRLIMIT(2) Linux Programmer's Manual GETRLIMIT(2)
2
6 getrlimit, setrlimit - get/set resource limits
7
9 #include <sys/time.h>
10 #include <sys/resource.h>
11 int getrlimit(int resource, struct rlimit *rlim);
13 int setrlimit(int resource, const struct rlimit *rlim);
14
16 getrlimit() and setrlimit() get and set resource limits respectively.
17 Each resource has an associated soft and hard limit, as defined by the
18 rlimit structure (the rlim argument to both getrlimit() and setr‐
19 limit()):
20 struct rlimit {
22 rlim_t rlim_cur; /* Soft limit */
23 rlim_t rlim_max; /* Hard limit (ceiling for rlim_cur) */
24 };
25 The soft limit is the value that the kernel enforces for the corre‐
27 sponding resource. The hard limit acts as a ceiling for the soft
28 limit: an unprivileged process may only set its soft limit to a value
29 in the range from 0 up to the hard limit, and (irreversibly) lower its
30 hard limit. A privileged process (under Linux: one with the
31 CAP_SYS_RESOURCE capability) may make arbitrary changes to either limit
32 value.
33 The value RLIM_INFINITY denotes no limit on a resource (both in the
35 structure returned by getrlimit() and in the structure passed to setr‐
36 limit()).
37 resource must be one of:
39 RLIMIT_AS
41 The maximum size of the process's virtual memory (address space)
42 in bytes. This limit affects calls to brk(2), mmap(2) and
43 mremap(2), which fail with the error ENOMEM upon exceeding this
44 limit. Also automatic stack expansion will fail (and generate a
45 SIGSEGV that kills the process if no alternate stack has been
46 made available via sigaltstack(2)). Since the value is a long,
47 on machines with a 32-bit long either this limit is at most 2
48 GiB, or this resource is unlimited.
49 RLIMIT_CORE
51 Maximum size of core file. When 0 no core dump files are cre‐
52 ated. When non-zero, larger dumps are truncated to this size.
53 RLIMIT_CPU
55 CPU time limit in seconds. When the process reaches the soft
56 limit, it is sent a SIGXCPU signal. The default action for this
57 signal is to terminate the process. However, the signal can be
58 caught, and the handler can return control to the main program.
59 If the process continues to consume CPU time, it will be sent
60 SIGXCPU once per second until the hard limit is reached, at
61 which time it is sent SIGKILL. (This latter point describes
62 Linux 2.2 through 2.6 behaviour. Implementations vary in how
63 they treat processes which continue to consume CPU time after
64 reaching the soft limit. Portable applications that need to
65 catch this si