It seems cmd or print methods of Net::Telnet package can handle at most 255 characters. Beyond that the command is truncated. The behaviour is reproducible both on Solaris 8 and AIX 5.1. with latest versions of perl and Telnet package.

Suspect the problem with _put method where it calls syswrite. Has anybody found any similar problem? Is it a feature of telnet protocol or a genuine bug? I couldn't find any logged bug for this scenerio.

Our current approach is to break the command string to smaller chunks and send again and again using put function. But a preferable way would be to specify max command length as a parameter like timeout.

A test program is pasted 

################
#!/spare/perl/bin/perl

use Net::Telnet;
my $t = new Net::Telnet(Host=> "myhost", Timeout=> 20);
$t->login("mylogin", "mypasswd");
@lines = $t->cmd("echo ddddddddddddddddddddddddddddddddddddddddddddddd
+ddddddddddddddddddddeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+eeeeeeeeeeeeeeebbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+);
print @lines;
###########################

[download]
Could somebody enlighten me on this issue?

Thanks and regards,

Debashish.

In reply to Maximum length of commands in Net::Telnet package by deba

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