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.TH ULIMIT "1P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH 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.

.SH NAME

ulimit

\(em set or report file size limit

.SH SYNOPSIS

.LP

.nf

ulimit \fB[\fR\(mif\fB] [\fIblocks\fB]\fR

.fi

.SH DESCRIPTION

The

.IR 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.

.SH OPTIONS

The

.IR ulimit

utility shall conform to the Base Definitions volume of POSIX.1\(hy2008,

.IR "Section 12.2" ", " "Utility Syntax Guidelines".

.P

The following option shall be supported:

.IP "\fB\(mif\fP" 10

Set (or report, if no

.IR blocks

operand is present), the file size limit in blocks. The

.BR \(mif

option shall also be the default case.

.SH OPERANDS

The following operand shall be supported:

.IP "\fIblocks\fR" 10

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

.SH STDIN

Not used.

.SH "INPUT FILES"

None.

.SH "ENVIRONMENT VARIABLES"

The following environment variables shall affect the execution of

.IR ulimit :

.IP "\fILANG\fP" 10

Provide a default value for the internationalization variables that are

unset or null. (See the Base Definitions volume of POSIX.1\(hy2008,

.IR "Section 8.2" ", " "Internationalization Variables"

for the precedence of internationalization variables used to determine

the values of locale categories.)

.IP "\fILC_ALL\fP" 10

If set to a non-empty string value, override the values of all the

other internationalization variables.

.IP "\fILC_CTYPE\fP" 10

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).

.IP "\fILC_MESSAGES\fP" 10

.br

Determine the locale that should be used to affect the format and

contents of diagnostic messages written to standard error.

.IP "\fINLSPATH\fP" 10

Determine the location of message catalogs for the processing of

.IR LC_MESSAGES .

.SH "ASYNCHRONOUS EVENTS"

Default.

.SH STDOUT

The standard output shall be used when no

.IR 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:

.sp

.RS 4

.nf

\fB

"%d\en", <\fInumber of 512-byte blocks\fR>

.fi \fR

.P

.RE

.P

If there is no current limit on the number of blocks, in the POSIX

locale the following format shall be used:

.sp

.RS 4

.nf

\fB

"unlimited\en"

.fi \fR

.P

.RE

.SH STDERR

The standard error shall be used only for diagnostic messages.

.SH "OUTPUT FILES"

None.

.SH "EXTENDED DESCRIPTION"

None.

.SH "EXIT STATUS"

The following exit values shall be returned:

.IP "\00" 6

Successful completion.

.IP >0 6

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

.SH "CONSEQUENCES OF ERRORS"

Default.

.LP

.IR "The following sections are informative."

.SH "APPLICATION USAGE"

Since

.IR 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:

.sp

.RS 4

.nf

\fB

nohup ulimit \(mif 10000

env ulimit 10000

.fi \fR

.P

.RE

.P

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

.P

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.

.SH EXAMPLES

Set the file size limit to 51\|200 bytes:

.sp

.RS 4

.nf

\fB

ulimit \(mif 100

.fi \fR

.P

.RE

.SH RATIONALE

None.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

The Base Definitions volume of POSIX.1\(hy2008,

.IR "Chapter 8" ", " "Environment Variables",

.IR "Section 12.2" ", " "Utility Syntax Guidelines"

.P

The System Interfaces volume of POSIX.1\(hy2008,

.IR "\fIulimit\fR\^(\|)"

.SH 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 .