Question

I am writing a perl script to start vnc session.

Firsr I need to rsh to a server then load a module, next execute the “vncserver -otp”.

my $mod=`module load turbovnc-1.0.0; vncserver -otp 2> tmp_vnc.log`;

my $launch=`rsh $host /"$mod/"`;

print $launch;

But it does not work, any suggestions??

Thanks!!

Answer 1

Did you mean to use backticks in your first line?

my $mod=`module load turbovnc-1.0.0; vncserver -otp 2> tmp_vnc.log`;

This sets $mod to be the output of this sequence of commands, like running

(module load turbovnc-1.0.0; vncserver -otp 2> tmp_vnc.log) | rsh $host

from the shell. You probably wanted to say

my $mod='module load turbovnc-1.0.0; vncserver -otp 2> tmp_vnc.log';

which will set you up to run those specific commands on the remote host, and execute

rsh $host "module load turbovnc-1.0.0; vncserver -otp 2> tmp_vnc.log"

---

It also looks like in the rsh command that you are trying to escape the quotation marks with forward slashes. In Perl (and in everything else as far as I know), use a backslash to escape a special character.

my $launch=`rsh $host /"$mod/"`;    # / wrong /
my $launch=`rsh $host \"$mod\"`;    # \ right \
my $launch=`rsh $host "$mod"`;      # right, esc is not reqd in this case