IPC::Run::IO

IPC::Run::IO(3)	     User Contributed Perl Documentation      IPC::Run::IO(3)



NAME
       IPC::Run::IO -- I/O channels for IPC::Run.

SYNOPSIS
       NOT IMPLEMENTED YET ON Win32! Win32 does not allow select() on normal
       file descriptors; IPC::RUN::IO needs to use IPC::Run::Win32Helper to
       do this.

	  use IPC::Run qw( io ) ;

	  ## The sense of ’>’ and ’<’ is opposite of perl’s open(),
	  ## but agrees with IPC::Run.
	  $io = io( "filename", ’>’,  \$recv ) ;
	  $io = io( "filename", ’r’,  \$recv ) ;

	  ## Append to $recv:
	  $io = io( "filename", ’>>’, \$recv ) ;
	  $io = io( "filename", ’ra’, \$recv ) ;

	  $io = io( "filename", ’<’,  \$send ) ;
	  $io = io( "filename", ’w’,  \$send ) ;

	  $io = io( "filename", ’<<’, \$send ) ;
	  $io = io( "filename", ’wa’, \$send ) ;

	  ## Handles / IO objects that the caller opens:
	  $io = io( \*HANDLE,	’<’,  \$send ) ;

	  $f = IO::Handle->new( ... ) ; # Any subclass of IO::Handle
	  $io = io( $f, ’<’, \$send ) ;

	  require IPC::Run::IO ;
	  $io = IPC::Run::IO->new( ... ) ;

	  ## Then run(), harness(), or start():
	  run $io, ... ;

	  ## You can, of course, use io() or IPC::Run::IO->new() as an
	  ## argument to run(), harness, or start():
	  run io( ... ) ;

DESCRIPTION
       This class and module allows filehandles and filenames to be harnessed
       for I/O when used IPC::Run, independant of anything else IPC::Run is
       doing (except that errors & exceptions can affect all things that
       IPC::Run is doing).

SUBCLASSING
       INCOMPATIBLE CHANGE: due to the awkwardness introduced in ripping
       pseudohashes out of Perl, this class no longer uses the fields pragma.

TODO
       Implement bidirectionality.

AUTHOR
       Barrie Slaymaker <barries@slaysys.com>

filename
Gets/sets the filename.	 Returns the value after the name change, if any.

init
Does initialization required before this can be run.  This includes open()ing
the file, if necessary, and clearing the destination scalar if necessary.

open
If a filename was passed in, opens it.	Determines if the handle is open via
fileno().  Throws an exception on error.

open_pipe
If this is a redirection IO object, this opens the pipe in a platform inde-
pendant manner.

close
Closes the handle.  Throws an exception on failure.

fileno
Returns the fileno of the handle.  Throws an exception on failure.

mode
Returns the operator in terms of ’r’, ’w’, and ’a’.  There is a state ’ra’,
unlike Perl’s open(), which indicates that data read from the handle or file
will be appended to the output if the output is a scalar.  This is only mean-
ingful if the output is a scalar, it has no effect if the output is a subrou-
tine.

The redirection operators can be a little confusing, so here’s a reference
table:

   >	  r	 Read from handle in to process
   <	  w	 Write from process out to handle
   >>	  ra	 Read from handle in to process, appending it to existing
		 data if the destination is a scalar.
   <<	  wa	 Write from process out to handle, appending to existing
		 data if IPC::Run::IO opened a named file.

op
Returns the operation: ’<’, ’>’, ’<<’, ’>>’.  See "mode" if you want to spell
these ’r’, ’w’, etc.

binmode
Sets/gets whether this pipe is in binmode or not.  No effect off of Win32
OSs, of course, and on Win32, no effect after the harness is start()ed.

dir
Returns the first character of $self->op.  This is either "<" or ">".



perl v5.8.8			  2006-05-10		      IPC::Run::IO(3)