Bash While loop new arguments

Question

Hi can someone please help me with an infinite loop that is to take new arguments. Is there a read command that each space as a new argument like the command line does. all seem to set it all to one big argument

I have a script, when called it enters an infinite loop. The first argument will determine a case to call another script, the second argument will then be sent to that script. I then want to loop around again and ask the user for two arguments again in the same line. The first determining the case and using the second...

However I want these to be in the one line as if it was the command line. I believe the read command will set the whole line to a variable while i want to do $1 and $2 again.

I provided a little code to describe my issue, thank you in advance

I basically need a read command that will split into arguments like the command line.

while true :
do

        # make decision using case..in..esac 
        choice = $1
        case $choice in
                create)

                        ./create.sh $2
                        ;;
                add)
                        ./add.sh $2     

                        ;;
                    *)
                        echo "Error: Invalid option..." 
                        ;;
        esac
done

@AshutoshJindal So you changed the code in this question, making it behave differently from what OP actually uses? — melpomene
– melpomene, Commented Oct 28, 2016 at 18:55
"I believe the read command will set the whole line to a variable while i want to do $1 and $2 again." Try read one two. — John1024
– John1024, Commented Oct 28, 2016 at 18:57
Kakawak, changes made by my edit removed these warnings. Check if you are happy with these please? If not, revert my edit. — Ashutosh Jindal
– Ashutosh Jindal, Commented Oct 28, 2016 at 19:02

cxw · Accepted Answer · 2016-10-28 19:01:25Z

2

You want to "ask the user for two arguments." There are at least three ways, listed below. I think you want to put any of these after the do and before the case.

Like @John1024 said,
```
read choice second_arg
```
will fill in $choice and $second_arg. Edit use choice directly and you won't need choice="$1".
This sequence:
```
read
set -- $REPLY
```
will replace $1, $2, ... with the words from the command line. Then you can still use choice="$1" like you have it.
To keep the command line parameters and be more general,
```
read -a inputs
```
will read the words into the array inputs, so you can reference them as ${inputs[0]}, ${inputs[1]}, ... for however many inputs there are. Then you can use
```
choice="${inputs[0]}"
```
rather than choice="$1".

answered Oct 28, 2016 at 19:01

cxw

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Faizan Younus · Accepted Answer · 2016-10-28 19:08:51Z

0

Hope this helps.

while true :
do
    echo -n "Enter Your Choice  > "
    read text

    arg1=$(echo "$text" | awk '{print $1}')
    arg2=$(echo "$text" | awk '{print $2}')
    # make decision using case..in..esac 
    choice="$arg1"
    case $choice in
            create)

                    ./create.sh $arg2
                    ;;
            add)
                    ./add.sh $arg2    
                    ;;
                *)
                    echo "Error: Invalid option..." 
                    ;;
    esac
done

answered Oct 28, 2016 at 19:08

Faizan Younus

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