ulimit

ULIMIT(1POSIX)              POSIX Programmer's Manual             ULIMIT(1POSIX)



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.1‐2008, 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.1‐2008, 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.1‐2008, Chapter 8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

       The System Interfaces volume of POSIX.1‐2008, ulimit()

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical
       and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008
       with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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                   2013                        ULIMIT(1POSIX)