|
|
| |
IPC::Run::IO(3) |
User Contributed Perl Documentation |
IPC::Run::IO(3) |
IPC::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 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( ... );
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.
- 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
independent 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 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 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 ">".
- poll
- TODO: Needs confirmation that this is correct. Was previously
undocumented.
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
gotten.
Barrie Slaymaker <barries@slaysys.com>
Implement bidirectionality.
Visit the GSP FreeBSD Man Page Interface. Output converted with ManDoc. |