PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

NAME

       ulimit — set or report file size limit

SYNOPSIS

       ulimit [-f] [blocks]

DESCRIPTION

       The  ulimit utility shall set or report the file-size writing limit imposed on files written by the shell
       and its child processes (files of any size may be read). Only a process with appropriate  privileges  can
       increase the limit.

OPTIONS

       The  ulimit  utility  shall conform to the Base Definitions volume of POSIX.1‐2017, Section 12.2, Utility
       Syntax Guidelines.

       The following option shall be supported:

       -f        Set (or report, if no blocks operand is present), the file size limit in blocks. The -f  option
                 shall also be the default case.

OPERANDS

       The following operand shall be supported:

       blocks    The number of 512-byte blocks to use as the new file size limit.

STDIN

       Not used.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of ulimit:

       LANG      Provide a default value for the internationalization variables that are unset or null. (See the
                 Base  Definitions  volume  of POSIX.1‐2017, Section 8.2, Internationalization Variables for the
                 precedence  of  internationalization  variables  used  to  determine  the  values   of   locale
                 categories.)

       LC_ALL    If  set  to a non-empty string value, override the values of all the other internationalization
                 variables.

       LC_CTYPE  Determine the locale for the interpretation of sequences of bytes of text  data  as  characters
                 (for example, single-byte as opposed to multi-byte characters in arguments).

       LC_MESSAGES
                 Determine  the  locale  that  should  be  used  to affect the format and contents of diagnostic
                 messages written to standard error.

       NLSPATH   Determine the location of message catalogs for the processing of LC_MESSAGES.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       The standard output shall be used when no blocks operand is present. If the current number of  blocks  is
       limited, the number of blocks in the current limit shall be written in the following format:

           "%d\n", <number of 512-byte blocks>

       If  there  is no current limit on the number of blocks, in the POSIX locale the following format shall be
       used:

           "unlimited\n"

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0    Successful completion.

       >0    A request for a higher limit was rejected or an error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       Since ulimit affects the current shell execution environment, it is always provided as  a  shell  regular
       built-in. If it is called in a separate utility execution environment, such as one of the following:

           nohup ulimit -f 10000
           env ulimit 10000

       it does not affect the file size limit of the caller's environment.

       Once  a  limit has been decreased by a process, it cannot be increased (unless appropriate privileges are
       involved), even back to the original system limit.

EXAMPLES

       Set the file size limit to 51200 bytes:

           ulimit -f 100

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of POSIX.1‐2017, Chapter 8,  Environment  Variables,  Section  12.2,  Utility
       Syntax Guidelines

       The System Interfaces volume of POSIX.1‐2017, ulimit()

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                        ULIMIT(1POSIX)