1ULIMIT(1P) POSIX Programmer's Manual ULIMIT(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
13 ulimit — set or report file size limit
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16 ulimit [−f] [blocks]
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19 The ulimit utility shall set or report the file-size writing limit
20 imposed on files written by the shell and its child processes (files of
21 any size may be read). Only a process with appropriate privileges can
22 increase the limit.
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25 The ulimit utility shall conform to the Base Definitions volume of
26 POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
27 The following option shall be supported:
29 −f Set (or report, if no blocks operand is present), the file
31 size limit in blocks. The −f option shall also be the default
32 case.
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35 The following operand shall be supported:
36 blocks The number of 512-byte blocks to use as the new file size
38 limit.
39
41 Not used.
42
44 None.
45
47 The following environment variables shall affect the execution of
48 ulimit:
49 LANG Provide a default value for the internationalization vari‐
51 ables that are unset or null. (See the Base Definitions vol‐
52 ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
53 ables for the precedence of internationalization variables
54 used to determine the values of locale categories.)
55 LC_ALL If set to a non-empty string value, override the values of
57 all the other internationalization variables.
58 LC_CTYPE Determine the locale for the interpretation of sequences of
60 bytes of text data as characters (for example, single-byte as
61 opposed to multi-byte characters in arguments).
62 LC_MESSAGES
64 Determine the locale that should be used to affect the format
65 and contents of diagnostic messages written to standard
66 error.
67 NLSPATH Determine the location of message catalogs for the processing
69 of LC_MESSAGES.
70
72 Default.
73
75 The standard output shall be used when no blocks operand is present. If
76 the current number of blocks is limited, the number of blocks in the
77 current limit shall be written in the following format:
78 "%d\n", <number of 512-byte blocks>
80 If there is no current limit on the number of blocks, in the POSIX
82 locale the following format shall be used:
83 "unlimited\n"
85
87 The standard error shall be used only for diagnostic messages.
88
90 None.
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93 None.
94
96 The following exit values shall be returned:
97 0 Successful completion.
99 >0 A request for a higher limit was rejected or an error occurred.
101
103 Default.
104 The following sections are informative.
106
108 Since ulimit affects the current shell execution environment, it is
109 always provided as a shell regular built-in. If it is called in a sepa‐
110 rate utility execution environment, such as one of the following:
111 nohup ulimit −f 10000
113 env ulimit 10000
114 it does not affect the file size limit of the caller's environment.
116 Once a limit has been decreased by a process, it cannot be increased
118 (unless appropriate privileges are involved), even back to the original
119 system limit.
120
122 Set the file size limit to 51200 bytes:
123 ulimit −f 100
125
127 None.
128
130 None.
131
133 The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
134 Variables, Section 12.2, Utility Syntax Guidelines
135 The System Interfaces volume of POSIX.1‐2008, ulimit()
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139 Portions of this text are reprinted and reproduced in electronic form
140 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
141 -- Portable Operating System Interface (POSIX), The Open Group Base
142 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
143 cal and Electronics Engineers, Inc and The Open Group. (This is
144 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
145 event of any discrepancy between this version and the original IEEE and
146 The Open Group Standard, the original IEEE and The Open Group Standard
147 is the referee document. The original Standard can be obtained online
148 at http://www.unix.org/online.html .
149 Any typographical or formatting errors that appear in this page are
151 most likely to have been introduced during the conversion of the source
152 files to man page format. To report such errors, see https://www.ker‐
153 nel.org/doc/man-pages/reporting_bugs.html .
154IEEE/The Open Group 2013 ULIMIT(1P)