How to iterate over arguments in a Bash script

Question

I have a complex command that I\'d like to make a shell/bash script of. I can write it in terms of $1 easily:

foo $1 args -o $1.ext
         


        

Answer 1

Amplifying on baz's answer, if you need to enumerate the argument list with an index (such as to search for a specific word), you can do this without copying the list or mutating it.

Say you want to split an argument list at a double-dash ("--") and pass the arguments before the dashes to one command, and the arguments after the dashes to another:

 toolwrapper() {
   for i in $(seq 1 $#); do
     [[ "${!i}" == "--" ]] && break
   done || return $? # returns error status if we don't "break"

   echo "dashes at $i"
   echo "Before dashes: ${@:1:i-1}"
   echo "After dashes: ${@:i+1:$#}"
 }

Results should look like this:

 $ toolwrapper args for first tool -- and these are for the second
 dashes at 5
 Before dashes: args for first tool
 After dashes: and these are for the second