How can I iterate through options provided to a shell script through a command line?

Question

I have a script that can be provided with [the potential] to have an unknown quantity of known arguments

That is, I know ALL the arguments that can be provided, but as they are all optional, they may not be getting provided all the time.

I have written this code (below), how can I send all the arguments provided to the 'setOptions' function? once they.are there I can iterate through them and process whats needed, but I don't have a clue how to pass them to the function.

Basically the case just checks to see if B or anything else is provided, if B then thats fine, but anything else needs to be iterated through and tested.

at the moment Im able to test if the value is a B or not and from there... well you can see.

  # request statement
  echo  "Enter 'B' to build or the name of test you wish to run."
  read testOptions
  # check the options
  case $testOptions in
    B )
      # tell them the tests are being rebuilt
      echo " The test will be rebuilt"
      COMMAND_LINE=$COMMAND_LINE" build"
      # display the command to be used and execute it.
      echo $COMMAND_LINE
      $COMMAND_LINE
    ;;
    * )
      # we are not rebuilding, take all the options and send to processing
      setOptions $testOptions #<- processes and builds the commandline from the  arguments
      # Execute the command
      executeOptions $testOptions #<- executes the command line
    ;;
  esac

I am honestly not sure, I know very little when it comes to shell script, if this was php, C# or JS I would be over and done with, but this is a bit different, and quite enjoyable tbh! — JimmyBorofan
– JimmyBorofan, Commented Jan 24, 2023 at 15:52
The penny may have dropped for me just then, so if I were to use sendOptions $testOptions Then in the function sendOptions, I would use read -a $1 and basically a case var in $1 .... iteration code... easc — JimmyBorofan
– JimmyBorofan, Commented Jan 24, 2023 at 15:56
You don't usually use $ in read: it takes zero or more variable names. — Davis Herring
– Davis Herring, Commented Jan 25, 2023 at 8:04

Adam Katz · Accepted Answer · 2025-07-07 15:54:21Z

0

If you're using bash, read -a testOptions is a simple way to parse the inputted line into an array (as noted by @DavisHerring).

If you're using POSIX shell (/bin/sh), the only type of array it supports is from the command line, $@. While you can use set to populate it, that's not necessary to simply loop through the fields represented by a user-inputted line:

IFS= read -r testOptions
for option in $testOptions; do
  case "$option" in
    # …
  esac
done

Note that the for command intentionally omits quotes around $testOptions (otherwise, you'd only find one option). This also lets you change the delimiter by setting IFS. If you do that, I recommend doing so with a local variable in a function, as other programs will get mangled with nonstandard $IFS values.

answered Jul 7 at 15:54

Adam Katz

16.3k5 gold badges80 silver badges94 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How can I iterate through options provided to a shell script through a command line?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related