mkfifo.1p (5612B)
- '\" et
- .TH MKFIFO "1P" 2017 "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
- mkfifo
- \(em make FIFO special files
- .SH SYNOPSIS
- .LP
- .nf
- mkfifo \fB[\fR-m \fImode\fB] \fIfile\fR...
- .fi
- .SH DESCRIPTION
- The
- .IR mkfifo
- utility shall create the FIFO special files specified by the operands,
- in the order specified.
- .P
- For each
- .IR file
- operand, the
- .IR mkfifo
- utility shall perform actions equivalent to the
- \fImkfifo\fR()
- function defined in the System Interfaces volume of POSIX.1\(hy2017, called with the following arguments:
- .IP " 1." 4
- The
- .IR file
- operand is used as the
- .IR path
- argument.
- .IP " 2." 4
- The value of the bitwise-inclusive OR of S_IRUSR, S_IWUSR, S_IRGRP,
- S_IWGRP, S_IROTH, and S_IWOTH is used as the
- .IR mode
- argument. (If the
- .BR \-m
- option is specified, the value of the
- \fImkfifo\fR()
- .IR mode
- argument is unspecified, but the FIFO shall at no time have permissions
- less restrictive than the
- .BR \-m
- .IR mode
- option-argument.)
- .SH OPTIONS
- The
- .IR mkfifo
- utility shall conform to the Base Definitions volume of POSIX.1\(hy2017,
- .IR "Section 12.2" ", " "Utility Syntax Guidelines".
- .P
- The following option shall be supported:
- .IP "\fB\-m\ \fImode\fR" 10
- Set the file permission bits of the newly-created FIFO to the specified
- .IR mode
- value. The
- .IR mode
- option-argument shall be the same as the
- .IR mode
- operand defined for the
- .IR chmod
- utility. In the
- .IR symbolic_mode
- strings, the
- .IR op
- characters
- .BR '\(pl'
- and
- .BR '\-'
- shall be interpreted relative to an assumed initial mode of
- .IR a =\c
- .IR rw .
- .SH OPERANDS
- The following operand shall be supported:
- .IP "\fIfile\fR" 10
- A pathname of the FIFO special file to be created.
- .SH STDIN
- Not used.
- .SH "INPUT FILES"
- None.
- .SH "ENVIRONMENT VARIABLES"
- The following environment variables shall affect the execution of
- .IR mkfifo :
- .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\(hy2017,
- .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
- Not used.
- .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
- All the specified FIFO special files were created successfully.
- .IP >0 6
- An error occurred.
- .SH "CONSEQUENCES OF ERRORS"
- Default.
- .LP
- .IR "The following sections are informative."
- .SH "APPLICATION USAGE"
- None.
- .SH EXAMPLES
- None.
- .SH RATIONALE
- This utility was added to permit shell applications to create FIFO
- special files.
- .P
- The
- .BR \-m
- option was added to control the file mode, for consistency with the
- similar functionality provided by the
- .IR mkdir
- utility.
- .P
- Early proposals included a
- .BR \-p
- option similar to the
- .IR mkdir
- .BR \-p
- option that created intermediate directories leading up to the FIFO
- specified by the final component. This was removed because it is not
- commonly needed and is not common practice with similar utilities.
- .P
- The functionality of
- .IR mkfifo
- is described substantially through a reference to the
- \fImkfifo\fR()
- function in the System Interfaces volume of POSIX.1\(hy2017. For example, by default, the mode of the FIFO
- file is affected by the file mode creation mask in accordance with the
- specified behavior of the
- \fImkfifo\fR()
- function. In this way, there is less duplication of effort required for
- describing details of the file creation.
- .SH "FUTURE DIRECTIONS"
- None.
- .SH "SEE ALSO"
- .IR "\fIchmod\fR\^",
- .IR "\fIumask\fR\^"
- .P
- The Base Definitions volume of POSIX.1\(hy2017,
- .IR "Chapter 8" ", " "Environment Variables",
- .IR "Section 12.2" ", " "Utility Syntax Guidelines"
- .P
- The System Interfaces volume of POSIX.1\(hy2017,
- .IR "\fImkfifo\fR\^(\|)"
- .\"
- .SH 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 .
- .PP
- 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 .