Question

I have need to execute a command in a script an arbitrary number of times with associated arbitrary parameters.

I’ve decided the script will take its cue from a parameter file (parameter.txt) where lines are of the form:

label param1 param2

For each line in parameter.txt, I’ll call the command with the specified parameters.

So far, my tinkering is moving along the lines of the following, but it’s looking messy:

while read line; do 
    echo $line | sed -r 's/[^ ]+ ([^ ]+).+/\1/' && 
        echo $line | sed -r 's/[^ ]+ [^ ]+ ([^ ]+)/\1/'
done < parameter.txt

My command is of the form:

mycmd -a param1 -b param2 > label

Could I get some suggestions how I might simplify this?

I’m doing this for a small embedded system whose ‘helper’ commands are in short supply (xargs for example isn’t available, and things like awk are hobbled busybox implementations), and I’m using version 2 (2.04g I think) of BASH.

Answer 1

while read label param1 param2; do
    mycmd -a "$param1" -b "$param2" > "$label"
done < parameter.txt