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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 IEEE Std 1003.1-2001, 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
       IEEE Std 1003.1-2001, 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  sym-
              bolic_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 variables
              that are unset or null. (See  the  Base  Definitions  volume  of
              IEEE Std 1003.1-2001,  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
       IEEE Std 1003.1-2001.  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  cre-
       ation.
FUTURE DIRECTIONS
       None.
SEE ALSO
       chmod(), umask(), the System Interfaces volume of IEEE Std 1003.1-2001,
       mkfifo()
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 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 .

IEEE/The Open Group                  2003                           MKFIFO(1P)