Shell Programming and Scripting

Hello All,

I was wondering how after processing a program down to the bottom of the program one can return to the only while loop in the program.

Thanx,

Using a Bourne type shell, it is not possible to set a goto to a specific arbitrary point in a shell script. Of course, you can use continue within a loop to return to the top of the loop. But Bourne type shells do not have the goto statement.

One alternative is make part of the script a function. Later in the script, you can call the function again. But that does not return you to a previous point in the script. It just calls the function again. Functions are useful.

Another alternative is to have the shell script call itself, with some argument that makes it skip down to the part of the script where the while loop starts. That sounds complicated and problematic to me.

Another alternative is to copy and paste the while loop code, and other logic, as needed, at the point you would like to put the goto. This would work, just be kind of lengthy.

Finally, csh and tchs (neither of which I use) do have the goto statement.

Thanx for the response. What I had to do was to wrap the code up in a while loop and use a continue at the bottom so that the program continues from the top of the loop again until the user makes a keyboard entry to exit. I appreciate the direction provided, it helped me decide on what approach to take.

You could try something like this:

Code:

echo enter y/n
while read answer
do
  case $answer in 
    [yY]) echo yes; break ;;
    [Nn]) echo no ; break ;;
  esac
done

You may want to split your single while loop into two: one to ask for and evaluate the user input (as scrutinizer posted), and a second, inner loop for your "real" code.

Yes, I do have other while loop in there now as well as a case structure.