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TCP Client is not working

by Rahul Gupta (Sexton)
on Aug 22, 2013 at 12:52 UTC ( #1050523=perlquestion: print w/ replies, xml ) Need Help??
Rahul Gupta has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I have developed code for remote communication with TCP.

Client code is

#!perl -w use strict; use IO::Socket::INET; my $channel_id = open_channel("127.0.0.1", "7777"); send_command($channel_id, "dir"); sub open_channel { # create a connecting socket my $host = shift; my $port = shift; if ( $host !~ m/(\d+)\.(\d+)\.(\d+).(\d+)/i ) { print "IP Address:'$host' is not a Valid IP-Address."; return 139; } my $socket = new IO::Socket::INET ( PeerHost => $host, PeerPort => $port, Proto => 'tcp', ); die "cannot connect to the server $!\n" unless $socket; if ( !defined $socket ) { print "Opening TCP Channel to host: $host and Port: $port Fail +ed !!"; return 138; } else { $socket->send("Check Connectivity"); while (1) { my $recieved_data= <$socket>; if ( defined $recieved_data ) { chomp($recieved_data); if ($recieved_data =~ /Connected to TCP socket server/ +i){ print "TCP Connection established with Channel id: + '$socket'\n"; return $socket; } else{ print "Cannot craete connection with server\n"; return 137; } } } #$socket->close(); } } sub send_command { my $channel_id = shift; my $command_to_send = shift; print "In send_command sub-routine:-Channel_id: '$channel_id' and + command: '$command_to_send'"; $| = 1; chomp($command_to_send); print $channel_id $command_to_send."\n"; while (1) { my $recieved_data = <$channel_id>; if ( defined $recieved_data ) { chomp($recieved_data); print "recieved_data=======>$recieved_data\n"; if ( $recieved_data =~ m/^done/i ) { return 0; } } } #$channel_id->close(); }

server code is:

#!/usr/bin/perl -w use strict; use IO::Socket::INET; my $Receiving_Port = 7777; # flush after every write $| = 1; my ( $socket, $received_data ); my ( $peeraddress, $peerport ); $socket = new IO::Socket::INET ( LocalHost => '127.0.0.1', LocalPort => $Receiving_Port, Proto => 'tcp', Listen => 5, Reuse => 1 ) or die "ERROR in Socket Creation : $!\n"; $socket->listen(); $socket->autoflush(1); print "TCP Server Started\n"; my $addr; while (1) { $addr = $socket->accept(); print "$addr\n"; $peeraddress = $addr->peerhost(); $peerport = $addr->peerport() ; if ( $^O !~ m/mswin32/i ) { $SIG{CHLD} = 'IGNORE'; } while (<$addr>) { # Read all messages from client # Print received message $received_data = $_; chomp($received_data); my $exitCode = RunCommand( $received_data, $peeraddress, $peer +port ); #exit $exitCode; } } $socket->close(); sub RunCommand { my $Command_To_Send = shift; my $send_ip = shift; my $peerport = shift; # file handler which will have response values. my $fileHandler; print "Executing: '$Command_To_Send'\n"; print "Output on: '$send_ip:$peerport'\n"; if ( $Command_To_Send =~ m/Check Connectivity/i ) { print $addr "Connected to TCP socket server\n"; return 0; } if ( $Command_To_Send =~ m/\x03|\x1A/i ) { return 0; } # and assign it to fileHandler. my @pid = open( $fileHandler, '-|', "$Command_To_Send 2>&1" ); if ( $^O !~ m/mswin32/i ) { #Traversing pid array. foreach (@pid) { print "'$Command_To_Send' PID: $_\n"; print $addr "Process ID = $_\n"; } } if ( $#pid == -1 ) { warn "Cannot Open Command !!\n"; print $addr "'$Command_To_Send' Unable to Start\n"; } my $ofh = select $fileHandler; $| = 1; select $ofh; print $addr "Sending Command '$Command_To_Send'\n"; while (<$fileHandler>) { print $addr $_; } print $addr "\n"; print $addr "normal-exit\n"; print $addr "done\n"; # Traversing pid array. foreach (@pid) { my $curr_pid = $_; if ( $^O !~ m/mswin32/i ) { kill 9, $curr_pid; } } close($fileHandler); return 0; }

Whenever i am executing the code ,it stucks at this point:

TCP Connection established with Channel id: 'IO::Socket::INET=GLOB(0x3 +494d8c)' In send_command sub-routine:-Channel_id: 'IO::Socket::INET=GLOB(0x349 +4d8c)' and command: 'dir'

Can anyone help me to resolve this issue.

Thanks in advance

Comment on TCP Client is not working
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Re: TCP Client is not working
by golux (Pilgrim) on Aug 22, 2013 at 13:52 UTC
    Hi Rahul Gupta,

    When you write to the socket from the client, be sure to put a newline at the end:

    $socket->send("Check Connectivity\n");

    That makes the program seem to work for me, all the way to:

    recieved_data=======>Sending Command 'dir' recieved_data=======>client.pl server.pl recieved_data=======> recieved_data=======>normal-exit recieved_data=======>done

    which it wasn't getting to before.

    say  substr+lc crypt(qw $i3 SI$),4,5

      Thanks for you reply.

      It worked for me :-)

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