Input redirection and for loop

Shell Programming and Scripting
1

Hello,

I need help with a bash script that I try to improve. I could not find answer so far, maybe because I'm not to familiar with the terminology so feel free to correct my language.

I have a script that looks like:

NODES="node_a node_b node_c"
for NODE in $NODES
do
    FILE=${NODE}.log
    
    connect << EOF > $FILE
        findVersion $NODE
EOF

    echo "$NODE completed."
 done

This works fine. My problem is that `connect' command takes long time to start and I wanted to do for loop inside the connect << EOF > ..... EOF construction so my connect command will be executed only once. The issue is that for will not work inside there and will be written to the input of connect command where it miserably fails.

Could someone suggest how can I overcome this?

THanks, PN.

2

It completely depends on how you would pass multiple commands to connect

Perhaps the following works?

connect <<EOF >$FILE
findVersion node_a
findVersion node_b
findVersion node_c
EOF
3

Thank you for reply. Of course your suggestion will work :). The problem is that my list is not limited to three entries. It's more closer to hundreds :slight_smile: It is generated automatically so hard coding it in the scripts seems to be an ugly way to go. I don't know, maybe what I'm trying to do is not possible in bash?
Thanks,
PN.

4 
for NODE in $NODES
do
  echo "    findVersion $NODE"
done | connect

However, if you want a separate log file for each node, you can't batch them like that (unless there is a way to specify a separate output file for each command inside the connect script).

5

Thank you! I think I'll use it since there is no requirement for separate logs.
PN