posix man page for mkfifo

MKFIFO(P)						     POSIX Programmer's Manual							 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:

	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 Technol-
       ogy -- 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(P)