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MKFIFO(1P)                 POSIX Programmer's Manual                MKFIFO(1P)
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.
NAME
       mkfifo -- make FIFO special files
SYNOPSIS
       mkfifo [-m mode] file...
DESCRIPTION
       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 equiva-
       lent to the mkfifo() function defined in the System  Interfaces  volume
       of POSIX.1-2008, 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
       The  mkfifo  utility  shall  conform  to the Base Definitions volume of
       POSIX.1-2008, 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
       The following operand shall be supported:
       file      A pathname of the FIFO special file to be created.
STDIN
       Not used.
INPUT FILES
       None.
ENVIRONMENT VARIABLES
       The  following  environment  variables  shall  affect  the execution of
       mkfifo:
       LANG      Provide a default value for  the  internationalization  vari-
                 ables  that are unset or null. (See the Base Definitions vol-
                 ume of POSIX.1-2008, Section 8.2, Internationalization  Vari-
                 ables  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
       Default.
STDOUT
       Not used.
STDERR
       The standard error shall be used only for diagnostic messages.
OUTPUT FILES
       None.
EXTENDED DESCRIPTION
       None.
EXIT STATUS
       The following exit values shall be returned:
        0    All the specified FIFO special files were created successfully.
       >0    An error occurred.
CONSEQUENCES OF ERRORS
       Default.
       The following sections are informative.
APPLICATION USAGE
       None.
EXAMPLES
       None.
RATIONALE
       This utility was added to permit shell applications to create FIFO spe-
       cial 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 refer-
       ence to the mkfifo()  function  in  the  System  Interfaces  volume  of
       POSIX.1-2008.  For  example,  by  default, the mode of the FIFO file is
       affected by the file mode creation mask in accordance with  the  speci-
       fied  behavior  of  the  mkfifo()  function. In this way, there is less
       duplication of effort required for describing details of the file  cre-
       ation.
FUTURE DIRECTIONS
       None.
SEE ALSO
       chmod, umask
       The  Base  Definitions  volume  of POSIX.1-2008, Chapter 8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines
       The System Interfaces volume of POSIX.1-2008, mkfifo()
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 Electri-
       cal 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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                           MKFIFO(1P)