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:

        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 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 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 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 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 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 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 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 .