Rman/linux question...

I am trying to write a script to remove old or unneeded archive logs. I want this to run from cron, so I'm writing a shell script. I've looked at MANY searched pages on how to do this, none of them seem to work. What I am trying to do, which comes up repeatedly on searches is this, ignore the actual run { } stuff - it does not get that far anyway:

connect target /
connect catalog rman/secretpass@rmancat 
run {
           allocate channel c1 type disk format '/orabak/%U';
           backup tablespace users;
}

I cannot get past the "connect target /". To run this I saved the file, called archivelog. I try to execute this by doing: