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



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult 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 IEEE Std 1003.1-2001,  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  IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of international-
              ization 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 stan-
              dard 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 num-
       ber 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 System Interfaces volume of IEEE Std 1003.1-2001, ulimit()

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                    ULIMIT(1P)