ulimit(1p) — Linux manual page

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 (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(3p)

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(1P)

Pages that refer to this page: prlimit(1), renice(1)

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