IPC::Run::IO(3pm) User Contributed Perl Documentation IPC::Run::IO(3pm)NAMEIPC::Run::IO-- I/O channels for IPC::Run.
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
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 );
$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( ... );
This class and module allows filehandles and filenames to be harnessed
for I/O when used IPC::Run, independent of anything else IPC::Run is
doing (except that errors & exceptions can affect all things that
IPC::Run is doing).
INCOMPATIBLE CHANGE: due to the awkwardness introduced in ripping
pseudohashes out of Perl, this class no longer uses the fields pragma.
new I think it takes >> or << along with some other data.
TODO: Needs more thorough documentation. Patches welcome.
Gets/sets the filename. Returns the value after the name change,
Does initialization required before this can be run. This includes
open()ing the file, if necessary, and clearing the destination
scalar if necessary.
If a filename was passed in, opens it. Determines if the handle is
open via fileno(). Throws an exception on error.
If this is a redirection IO object, this opens the pipe in a
platform independent manner.
Closes the handle. Throws an exception on failure.
Returns the fileno of the handle. Throws an exception on failure.
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 meaningful if the output is a
scalar, it has no effect if the output is a subroutine.
The redirection operators can be a little confusing, so here's a
> 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.
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
dir Returns the first character of $self->op. This is either "<" or
TODO: Needs confirmation that this is correct. Was previously
I believe this is polling the IO for new input and then returns
undef if there will never be any more input, 0 if there is none
now, but there might be in the future, and TRUE if more input was
Barrie Slaymaker <firstname.lastname@example.org>
perl v5.14.2 2012-01-16 IPC::Run::IO(3pm)