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#!/usr/bin/perl |
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# $Id$ |
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|
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# This program manages a child process started with POE::Wheel::Run. |
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# Wheel::Run is a lot like IPC::Run but event driven. Because it |
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# doesn't block, though, it can be instantiated several times to drive |
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# many child processes. |
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# |
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# This sample runs a single process, nethack, as its test program. It |
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# adds two "features" to stock nethack: |
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# |
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# 1. It changes all "@" characters to random colors. It's annoying, |
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# but it lets you know the program's working. |
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# |
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# 2. Ctrl+C sends a string of random movement commands to the child |
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# process. This causes your player to go a little berzerk. |
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|
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use warnings; |
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use strict; |
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|
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sub PROGRAM () { "nethack" } |
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|
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use POSIX; |
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use POE qw( Wheel::ReadWrite Wheel::Run Filter::Stream ); |
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|
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### Handle the _start event. This sets things in motion. |
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|
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sub handle_start { |
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my ( $kernel, $heap ) = @_[ KERNEL, HEAP ]; |
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|
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# Set a signal handler. |
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|
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$kernel->sig( CHLD => "got_sigchld" ); |
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|
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# Save the original terminal settings so they can be restored later. |
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|
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$heap->{stdin_tio} = POSIX::Termios->new(); |
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$heap->{stdin_tio}->getattr(0); |
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$heap->{stdout_tio} = POSIX::Termios->new(); |
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$heap->{stdout_tio}->getattr(1); |
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$heap->{stderr_tio} = POSIX::Termios->new(); |
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$heap->{stderr_tio}->getattr(2); |
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|
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# Put the terminal into raw input mode. Otherwise discrete |
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# keystrokes will not be read immediately. |
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|
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my $tio = POSIX::Termios->new(); |
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$tio->getattr(0); |
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my $lflag = $tio->getlflag; |
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$lflag &= ~( ECHO | ECHOE | ECHOK | ECHONL | ICANON | IEXTEN | ISIG ); |
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$tio->setlflag($lflag); |
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my $iflag = $tio->getiflag; |
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$iflag &= ~( BRKINT | INPCK | ISTRIP | IXON ); |
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$tio->setiflag($iflag); |
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my $cflag = $tio->getcflag; |
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$cflag &= ~( CSIZE | PARENB ); |
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$tio->setcflag($cflag); |
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$tio->setattr( 0, TCSANOW ); |
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|
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# Start the terminal reader/writer. |
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|
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$heap->{stdio} = POE::Wheel::ReadWrite->new |
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( InputHandle => \*STDIN, |
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OutputHandle => \*STDOUT, |
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InputEvent => "got_terminal_stdin", |
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Filter => POE::Filter::Stream->new(), |
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); |
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|
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# Start the asynchronous child process. |
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|
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$heap->{program} = POE::Wheel::Run->new |
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( Program => PROGRAM, |
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Conduit => "pty", |
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StdoutEvent => "got_child_stdout", |
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Filter => POE::Filter::Stream->new(), |
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); |
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} |
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|
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### Handle the _stop event. This restores the original terminal |
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### settings when we're done. That's very important. |
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|
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sub handle_stop { |
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my $heap = $_[HEAP]; |
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$heap->{stdin_tio}->setattr( 0, TCSANOW ); |
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$heap->{stdout_tio}->setattr( 1, TCSANOW ); |
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$heap->{stderr_tio}->setattr( 2, TCSANOW ); |
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} |
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|
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### Handle terminal STDIN. Send it to the background program's STDIN. |
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### If the user presses ^C, then also go berserk a little. |
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|
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sub handle_terminal_stdin { |
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my ( $heap, $input ) = @_[ HEAP, ARG0 ]; |
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|
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while ( $input =~ m/\003/g ) { |
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my $count = int( 5 + rand(10) ); |
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my $random_walk = ''; |
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$random_walk .= int( rand(9) + 1 ) while $count--; |
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$random_walk =~ tr[5][]d; |
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substr( $input, pos($input) - 1, 1 ) = $random_walk; |
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} |
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$heap->{program}->put($input); |
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} |
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|
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### Handle STDOUT from the child program. Send it to the terminal's |
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### STDOUT. Oh, and do something silly like change the foreground |
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### color of "@" characters to something random. :) |
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|
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sub handle_child_stdout { |
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my ( $heap, $input ) = @_[ HEAP, ARG0 ]; |
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my $color = int rand 8; |
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$input =~ s/\@/\e[3${color}m\@\e[0m/g; |
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$heap->{stdio}->put($input); |
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} |
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|
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### Handle SIGCHLD. Shut down if the exiting child process was the |
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### one we've been managing. |
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|
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sub handle_sigchld { |
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my ( $heap, $child_pid ) = @_[ HEAP, ARG1 ]; |
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if ( $child_pid == $heap->{program}->PID ) { |
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delete $heap->{program}; |
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delete $heap->{stdio}; |
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} |
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return 0; |
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} |
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|
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### Start a session to encapsulate the previous features. |
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|
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POE::Session->create |
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( inline_states => |
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{ _start => \&handle_start, |
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_stop => \&handle_stop, |
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got_terminal_stdin => \&handle_terminal_stdin, |
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got_child_stdout => \&handle_child_stdout, |
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got_sigchld => \&handle_sigchld, |
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}, |
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); |
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|
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### Start POE's main loop, which runs the session until it's done. |
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|
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$poe_kernel->run(); |
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exit 0; |
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