reading binary from a socket

philiotis has asked for the wisdom of the Perl Monks concerning the following question:

I can write binary to a socket that successfully gets processed by the server. When the server replies, again in binary, my client hangs. I tried using echo to debugg but again the same issue (works fine with ASCII). Below is part of the code:

 
#!/opt/perl5/bin/perl

use strict;
use Socket;

my $messageCounter = 0;
my $message;
my $reply;
my $length;
my $protocol = getprotobyname('tcp');
my $socketCreated;
my $remoteHost = "XXXXXX";
my $packed_ip;
my $remotePort = XXXX;
my $portAddress;
#BINARY OUTPUT FILE DEBUGGING ONLY
my $binfilename = "BINARY_OUTPUT_FILE";
my $open_binName = sprintf(">%s", $binfilename);

open(BIN_FILE, $open_binName) || die "can't open BIN_FILE: $!";
        
#Open Socket
$socketCreated =socket(SocketHandle,PF_INET,SOCK_STREAM ,$protocol);
        
$packed_ip = inet_aton($remoteHost);
$portAddress = sockaddr_in($remotePort, $packed_ip);
        
#Open Connection
connect(SocketHandle, $portAddress) || die print "Could not Establish 
+a Connection\n";
print "Connection Successfully Established\n";
        
#enable buffering 
select((select(SocketHandle), $| = 1)[0]);
    
$messageCounter++;
$message = DCPLogin($messageCounter); # returns the binary string
print SocketHandle $message;

#hangs here

while($length=sysread(SocketHandle, $reply, 1024)){ 
    print BIN_FILE $reply;
}#end while

        
close(BIN_FILE) || die "couldn't close BIN_FILE: $!";        #debuggin
+g only    
closeConn();    #function that closes the connection
[download]

Comment on reading binary from a socket Download Code

Replies are listed 'Best First'.
Re: reading binary from a socket by insensate (Hermit) on Nov 07, 2002 at 21:36 UTC
What happens when you add the following line? `open(BIN_FILE, $open_binName) \|\| die "can't open BIN_FILE: $!"; binmode BIN_FILE;` [download]	[reply] [d/l]
Re: Re: reading binary from a socket by philiotis (Initiate) on Nov 07, 2002 at 23:18 UTC
nothing I already tried that	[reply]
Re: reading binary from a socket by iburrell (Chaplain) on Nov 08, 2002 at 00:10 UTC
What do you mean hangs? Does it reach the read loop? Or do you mean that it never exits? One problem could be that your server doesn't close the socket. The read loop won't exit until the socket is closed (and sysread returns zero). One way to check this is put a "print STDERR" inside the loop. Another is to unbuffer output to BIN_FILE and see if anything shows up in it.	[reply]