10-07-2003
Miniature Shell - IO Redirection and Pipe line filters
hi,
I was trying to write a miniature shell (ie, command line interpreter) to implement the features like 'IO Redirection' and 'Pipe line fileters'.
Can anyone help me with sample shell sript to implement the above features.
cheers
supong
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LEARN ABOUT DEBIAN
poe::pipe::twoway
POE::Pipe::TwoWay(3pm) User Contributed Perl Documentation POE::Pipe::TwoWay(3pm)
NAME
POE::Pipe::TwoWay - a portable API for two-way pipes
SYNOPSIS
my ($a_read, $a_write, $b_read, $b_write) = POE::Pipe::TwoWay->new();
die "couldn't create a pipe: $!" unless defined $a_read;
DESCRIPTION
Pipes are troublesome beasts because there are a few different, incompatible ways to create them, and many operating systems implement some
subset of them. Therefore it's impossible to rely on a particular method for their creation.
POE::Pipe::TwoWay will attempt to create a bidirectional pipe using an appropriate method. If that fails, it will fall back to some other
means until success or all methods have been exhausted. Some operating systems require certain exceptions, which are hardcoded into the
library.
The upshot of all this is that an application can use POE::Pipe::TwoWay to create a bidirectional pipe without worrying about the mechanism
that works in the current run-time environment.
By the way, POE::Pipe::TwoWay doesn't use POE internally, so it may be used in stand-alone applications without POE.
PUBLIC METHODS
new [TYPE]
Create a new two-way pipe, optionally constraining it to a particular TYPE of pipe. Two-way pipes have two ends, both of which can be read
from and written to. Therefore, a successful new() call will return four handles: read and write for one end, and read and write for the
other. On failure, new() sets $! to describe the error and returns nothing.
my ($a_read, $a_write, $b_read, $b_write) = POE::Pipe::TwoWay->new();
die $! unless defined $a_read;
TYPE may be one of "pipe", "socketpair", or "inet". When set, POE::Pipe::TwoWay will constrain its search to either "pipe()", a UNIX-
domain "socketpair()", or plain old sockets, respectively. Otherwise new() will try each method in order, or a particular method
predetermined to be the best one for the current operating environment.
BUGS
POE::Pipe::OneWay may block up to one second on some systems if failure occurs while trying to create "inet" sockets.
SEE ALSO
POE::Pipe, POE::Pipe::OneWay.
AUTHOR & COPYRIGHT
POE::Pipe::TwoWay is copyright 2000-2008 by Rocco Caputo. All rights reserved. POE::Pipe::TwoWay is free software; you may redistribute
it and/or modify it under the same terms as Perl itself.
perl v5.14.2 2012-05-15 POE::Pipe::TwoWay(3pm)