1MKFIFO(P) POSIX Programmer's Manual MKFIFO(P)
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6 mkfifo - make FIFO special files
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9 mkfifo [-m mode] file...
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12 The mkfifo utility shall create the FIFO special files specified by the
13 operands, in the order specified.
14 For each file operand, the mkfifo utility shall perform actions equiva‐
16 lent to the mkfifo() function defined in the System Interfaces volume
17 of IEEE Std 1003.1-2001, called with the following arguments:
18 1. The file operand is used as the path argument.
20 2. The value of the bitwise-inclusive OR of S_IRUSR, S_IWUSR, S_IRGRP,
22 S_IWGRP, S_IROTH, and S_IWOTH is used as the mode argument. (If the
23 -m option is specified, the value of the mkfifo() mode argument is
24 unspecified, but the FIFO shall at no time have permissions less
25 restrictive than the -m mode option-argument.)
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28 The mkfifo utility shall conform to the Base Definitions volume of
29 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
30 The following option shall be supported:
32 -m mode
34 Set the file permission bits of the newly-created FIFO to the
35 specified mode value. The mode option-argument shall be the same
36 as the mode operand defined for the chmod utility. In the sym‐
37 bolic_mode strings, the op characters '+' and '-' shall be
38 interpreted relative to an assumed initial mode of a= rw.
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42 The following operand shall be supported:
43 file A pathname of the FIFO special file to be created.
45
48 Not used.
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51 None.
52
54 The following environment variables shall affect the execution of
55 mkfifo:
56 LANG Provide a default value for the internationalization variables
58 that are unset or null. (See the Base Definitions volume of
59 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
60 ables for the precedence of internationalization variables used
61 to determine the values of locale categories.)
62 LC_ALL If set to a non-empty string value, override the values of all
64 the other internationalization variables.
65 LC_CTYPE
67 Determine the locale for the interpretation of sequences of
68 bytes of text data as characters (for example, single-byte as
69 opposed to multi-byte characters in arguments).
70 LC_MESSAGES
72 Determine the locale that should be used to affect the format
73 and contents of diagnostic messages written to standard error.
74 NLSPATH
76 Determine the location of message catalogs for the processing of
77 LC_MESSAGES .
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81 Default.
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84 Not used.
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87 The standard error shall be used only for diagnostic messages.
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90 None.
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93 None.
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96 The following exit values shall be returned:
97 0 All the specified FIFO special files were created successfully.
99 >0 An error occurred.
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104 Default.
105 The following sections are informative.
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109 None.
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112 None.
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115 This utility was added to permit shell applications to create FIFO spe‐
116 cial files.
117 The -m option was added to control the file mode, for consistency with
119 the similar functionality provided by the mkdir utility.
120 Early proposals included a -p option similar to the mkdir -p option
122 that created intermediate directories leading up to the FIFO specified
123 by the final component. This was removed because it is not commonly
124 needed and is not common practice with similar utilities.
125 The functionality of mkfifo is described substantially through a refer‐
127 ence to the mkfifo() function in the System Interfaces volume of
128 IEEE Std 1003.1-2001. For example, by default, the mode of the FIFO
129 file is affected by the file mode creation mask in accordance with the
130 specified behavior of the mkfifo() function. In this way, there is less
131 duplication of effort required for describing details of the file cre‐
132 ation.
133
135 None.
136
138 chmod() , umask() , the System Interfaces volume of
139 IEEE Std 1003.1-2001, mkfifo()
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142 Portions of this text are reprinted and reproduced in electronic form
143 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
144 -- Portable Operating System Interface (POSIX), The Open Group Base
145 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
146 Electrical and Electronics Engineers, Inc and The Open Group. In the
147 event of any discrepancy between this version and the original IEEE and
148 The Open Group Standard, the original IEEE and The Open Group Standard
149 is the referee document. The original Standard can be obtained online
150 at http://www.opengroup.org/unix/online.html .
151IEEE/The Open Group 2003 MKFIFO(P)