mkfifo(1p) — Linux manual page

PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

MKFIFO(1P)              POSIX Programmer's Manual             MKFIFO(1P)

PROLOG         top

       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         top

       mkfifo — make FIFO special files

SYNOPSIS         top

       mkfifo [-m mode] file...

DESCRIPTION         top

       The mkfifo utility shall create the FIFO special files specified
       by the operands, in the order specified.

       For each file operand, the mkfifo utility shall perform actions
       equivalent to the mkfifo() function defined in the System
       Interfaces volume of POSIX.1‐2017, called with the following
       arguments:

        1. The file operand is used as the path argument.

        2. 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 mode
           argument. (If the -m option is specified, the value of the
           mkfifo() mode argument is unspecified, but the FIFO shall at
           no time have permissions less restrictive than the -m mode
           option-argument.)

OPTIONS         top

       The mkfifo utility shall conform to the Base Definitions volume
       of POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.

       The following option shall be supported:

       -m mode   Set the file permission bits of the newly-created FIFO
                 to the specified mode value. The mode option-argument
                 shall be the same as the mode operand defined for the
                 chmod utility. In the symbolic_mode strings, the op
                 characters '+' and '-' shall be interpreted relative to
                 an assumed initial mode of a=rw.

OPERANDS         top

       The following operand shall be supported:

       file      A pathname of the FIFO special file to be created.

STDIN         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       The following environment variables shall affect the execution of
       mkfifo:

       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         top

       Default.

STDOUT         top

       Not used.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       The following exit values shall be returned:

        0    All the specified FIFO special files were created
             successfully.

       >0    An error occurred.

CONSEQUENCES OF ERRORS         top

       Default.

       The following sections are informative.

APPLICATION USAGE         top

       None.

EXAMPLES         top

       None.

RATIONALE         top

       This utility was added to permit shell applications to create
       FIFO special files.

       The -m option was added to control the file mode, for consistency
       with the similar functionality provided by the mkdir utility.

       Early proposals included a -p option similar to the mkdir -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.

       The functionality of mkfifo is described substantially through a
       reference to the mkfifo() function in the System Interfaces
       volume of POSIX.1‐2017. 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 mkfifo() function.
       In this way, there is less duplication of effort required for
       describing details of the file creation.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       chmod(1p), umask(1p)

       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, mkfifo(3p)

COPYRIGHT         top

       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                        MKFIFO(1P)