ULIMIT - Manpage

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ulimit --help

ulimit --help
ulimit: ulimit [-SHabcdefiklmnpqrstuvxPRT] [limit]
    Modify shell resource limits.
    
    Provides control over the resources available to the shell and processes
    it creates, on systems that allow such control.
    
    Options:
      -S	use the `soft' resource limit
      -H	use the `hard' resource limit
      -a	all current limits are reported
      -b	the socket buffer size
      -c	the maximum size of core files created
      -d	the maximum size of a process's data segment
      -e	the maximum scheduling priority (`nice')
      -f	the maximum size of files written by the shell and its children
      -i	the maximum number of pending signals
      -k	the maximum number of kqueues allocated for this process
      -l	the maximum size a process may lock into memory
      -m	the maximum resident set size
      -n	the maximum number of open file descriptors
      -p	the pipe buffer size
      -q	the maximum number of bytes in POSIX message queues
      -r	the maximum real-time scheduling priority
      -s	the maximum stack size
      -t	the maximum amount of cpu time in seconds
      -u	the maximum number of user processes
      -v	the size of virtual memory
      -x	the maximum number of file locks
      -P	the maximum number of pseudoterminals
      -R	the maximum time a real-time process can run before blocking
      -T	the maximum number of threads
    
    Not all options are available on all platforms.
    
    If LIMIT is given, it is the new value of the specified resource; the
    special LIMIT values `soft', `hard', and `unlimited' stand for the
    current soft limit, the current hard limit, and no limit, respectively.
    Otherwise, the current value of the specified resource is printed.  If
    no option is given, then -f is assumed.
    
    Values are in 1024-byte increments, except for -t, which is in seconds,
    -p, which is in increments of 512 bytes, and -u, which is an unscaled
    number of processes.
    
    Exit Status:
    Returns success unless an invalid option is supplied or an error occurs.


Manpage

ulimit(3)                                                                                  Library Functions Manual                                                                                 ulimit(3)

NAME
       ulimit - get and set user limits

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <ulimit.h>

       [[deprecated]] long ulimit(int cmd, long newlimit);

DESCRIPTION
       Warning: this routine is obsolete.  Use getrlimit(2), setrlimit(2), and sysconf(3) instead.  For the shell command ulimit, see bash(1).

       The ulimit() call will get or set some limit for the calling process.  The cmd argument can have one of the following values.

       UL_GETFSIZE
              Return the limit on the size of a file, in units of 512 bytes.

       UL_SETFSIZE
              Set the limit on the size of a file.

       3      (Not implemented for Linux.)  Return the maximum possible address of the data segment.

       4      (Implemented but no symbolic constant provided.)  Return the maximum number of files that the calling process can open.

RETURN VALUE
       On success, ulimit() returns a nonnegative value.  On error, -1 is returned, and errno is set to indicate the error.

ERRORS
       EPERM  An unprivileged process tried to increase a limit.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                                                                                                                                  │ Attribute     │ Value   │
       ├───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ulimit()                                                                                                                                                                   │ Thread safety │ MT-Safe │
       └───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS
       SVr4, POSIX.1-2001.  POSIX.1-2008 marks ulimit() as obsolete.

SEE ALSO
       bash(1), getrlimit(2), setrlimit(2), sysconf(3)

Linux man-pages 6.03                                                                              2022-12-15                                                                                        ulimit(3)