##############################################################################################
# This subroutine receives command string as a first parameter and sends it to the remote host.
# Then it collects the output of the command as one big string ($CommandOutput). 
# End of the command is determined 
# by the prompt REGEX that is passed as the second argument to the function.
# showprogress argument is to control echoing of the output of the command to the terminal
# 0 - do not show, 1- verbose, 2 - show '#' sign for every new received chunk of command output 
# CommandOutput argument is to return output of the command to calling code for post-processing
# 04/14/06 Sergey A. Belous
# *******************************************************************************************
# 05/02/06 passing file handles correctly into subroutine
# 04/18/08 made as separate library for use in inline PERL PLUGINs
# 04/28/13 changed to "non-blocking select/sysread" (gco3.pl) to be able to reuse PLUGINs 
# in the GNU screen as robot filters ("Ctrl-a" ":" "exec !!. perl plugin.pl") 
# *******************************************************************************************
# example how to call:
# gco(\*STDIN,\*STDOUT,\*STDERR,"show sub aaa user $ARGV[0]\r\n","#",0, $buffer);
##############################################################################################

use IO::Select;
sub gco{
	my $myin = shift;
	my $myout = shift;
	my $myerr = shift;
	my $commandtoexecute = shift;
	my $promptregex = shift;
	my $showprogress = shift;
	#end of argument list, last one is in $_[0]
	#write command to shell and then do non-blocking non-buffered read till prompt is found
	syswrite $myout,"$commandtoexecute";
	$CommandOutput="";
	my $read_set = new IO::Select();#Create handle set for reading
	$read_set->add($myin);#add the reader handle to the set
	while()
		{
		if ($read_set->can_read(0))
				{
				sysread $myin,$greeting,10000;
				if($showprogress==1){syswrite $myerr,$greeting}
				if($showprogress==2){syswrite $myerr,"#"}
				$CommandOutput.=$greeting;
				if($CommandOutput =~/$promptregex/){last}
				}
		}
	$read_set->remove($myin);#remove the reader handle from the set
	$CommandOutput =~ s/[\r\x00]//g;#clean-up
	$_[0]=$CommandOutput;
}
1;