ulimit [OPTIONS] limit


Provides control over the resources available to the shell and to processes started by it, on systems that allow such control.

Frequently used options


Report all current limits.


The maximum number of processes available to a single user.


The maximum number of file locks.


The maximum amount of memory available to the shell, in kilobytes.


Indicates that a hard limit is being specified.


Indicates that a soft limit is being specified.


View the current limits for a user:

$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 8192
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 8192
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Limits are defined on Linux as being either hard or soft limits. A hard limit is set by the superuser for a user or group of users and cannot be exceeded. A soft limit is also set by the superuser, but it may be temporarily overridden by a user if the need arises (by the user calling the ulimit command). For example, a user may have a soft limit of 100 on the maximum number of open files, with a hard limit of 1,000. If the user is running ...

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