Linux in a Nutshell, 6th Edition

Name

ulimit

Synopsis

ulimit [options] [n]

Print the value of one or more resource limits, or, if n is specified, set a resource limit to n. Resource limits can be either hard (-H) or soft (-S). By default, ulimit sets both limits or prints the soft limit. The options determine which resource is acted on.

Options

-H

Hard limit. Anyone can lower a hard limit; only privileged users can raise it.

-S

Soft limit. Anyone can raise a soft limit up to the value of the hard limit.

-a

Print all limits.

-b

Maximum socket buffer size.

-c

Maximum size of core files.

-d

Maximum kilobytes of data segment or heap.

-e

Maximum scheduling priority (“nice”).

-f

Maximum size of files (the default option).

-i

Maximum number of pending signals.

-l

Maximum size of address space that can be locked in memory.

-m

Maximum kilobytes of physical memory. (Not effective on all Linux systems.)

-n

Maximum number of file descriptors.

-p

Maximum size of pipe buffers in 512-byte blocks. (May not be set.)

-q

Maximum number of bytes in POSIX message queues.

-r

Maximum real-time scheduling priority.

-s

Maximum stack size.

-t

Maximum CPU seconds.

-T

Maximum number of threads.

-u

Maximum number of processes a single user can have.

-v

Maximum kilobytes of virtual memory.

-x

Maximum number of file locks