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.
Hard limit. Anyone can lower a hard limit; only privileged users can raise it.
Soft limit. Anyone can raise a soft limit up to the value of the hard limit.
Print all limits.
Maximum socket buffer size.
Maximum size of core files.
Maximum kilobytes of data segment or heap.
Maximum scheduling priority (“nice”).
Maximum size of files (the default option).
Maximum number of pending signals.
Maximum size of address space that can be locked in memory.
Maximum kilobytes of physical memory. (Not effective on all Linux systems.)
Maximum number of file descriptors.
Maximum size of pipe buffers in 512-byte blocks. (May not be set.)
Maximum number of bytes in POSIX message queues.
Maximum real-time scheduling priority.
Maximum stack size.
Maximum CPU seconds.
Maximum number of threads.
Maximum number of processes a single user can have.
Maximum kilobytes of virtual memory.
Maximum number of file locks