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NAMEIPC::Run::IO -- I/O channels for IPC::Run.
NOT IMPLEMENTED YET ONWin32! Win32 does not allow select() on normal file descriptors;
IPC::RUN::IOneeds 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( ... );
DESCRIPTIONThis 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.
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, if any.
- 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 IOobject, 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 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.
- 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 start()ed.
- Returns the first character of $self->op. This is either ``<'' or ``>''.
TODO:Needs confirmation that this is correct. Was previously undocumented.
I believe this is polling theIOfor 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, andTRUEif more input was gotten.