mkfifo(P)                                             mkfifo(P)





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  equivalent  to the mkfifo() function defined in
       the System Interfaces  volume  of  IEEE Std 1003.1-2001,
       called with the following arguments:

       The file operand is used as the path argument.

       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 op-
              erand  defined for the chmod utility. In the sym-
              bolic_mode strings, the op characters '+' and '-'
              shall  be interpreted relative to an assumed ini-
              tial mode of a= rw.


OPERANDS
       The following operand shall be supported:

       file   A pathname of the FIFO special file  to  be  cre-
              ated.


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 internationaliza-
              tion  variables  that are unset or null. (See the
              Base Definitions volume of  IEEE Std 1003.1-2001,
              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 mes-
              sages 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 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 Sys-
       tem Interfaces volume of IEEE Std 1003.1-2001. For exam-
       ple, 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
       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 Operat-
       ing System Interface (POSIX), The Open Group Base Speci-
       fications Issue 6, Copyright (C) 2001-2003 by the Insti-
       tute 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.open-
       group.org/unix/online.html .



POSIX                         2003                    mkfifo(P)
