Shell Programming and Scripting

Originally Posted by bakunin

Yes: you have put everything - including the shebang line, which makes absoultely no sense - into a function and then called the function with no arguments. What is getopts supposed to work on when there are no options provided, hm?

You could have found that out easily yourself by putting an echo-statement here:

Code:

   f)
       file_in="$OPTARG"
       # a test for the file being readable/existing would fit nicely here, no?
       echo "now in -f option handling"
       lFUsed=1               # change flag when -f was indeed used
       ;;

and you would have immediately noticed that this part was not even executed. You could also have put a testwise echo-statement into the while-loop and show the values of "$opt" and "$OPTARG" during executing which would have yielded the same information. Finally you could have tried the sample script UNMODIFIEDLY first before you tinkered with it.

Don't get me wrong, it is meant to be tinkered with. But trying to understand it first before doing experiments (like putting everything into a function) is usually a good idea.

I hope this helps.

bakunin

Originally Posted by RudiC

Please indulge me jumping in:

1. It didn't hurt on the other hand, so the correction is a no op.
2. How did you become aware?

Why: You didn't, as explained by bakunin, pass -f nor filename. When calling a function, a new set of positional parameters is created by the shell to be worked upon in the function.

Originally Posted by mohtashims

k.. so are you saying the -f filename has to be read in variables outside the function and then passed to the callme() function for the check to happen ?

Originally Posted by mohtashims

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When i just remove the function and the local before the variable names the same script STRANGELY works fine. Can you tell me what's wrong i m doing by creating a function ?

When a function is executed, the arguments to the function become the positional parameters during its execution.

Originally Posted by Corona688

Hint:

What $1, $2, $3 arguments does your script have when you call it?

What $1, $2, $3, ... arguments do callme have?

Where does getopts get its opts?