Infinite loop while scripting case statement in bash

Question

Hello~ I've been trying to crack my head solving this for half a day.

INPUT=lookup.txt
IFS=":"
while read vTitle vAuthor vPrice vStock vSold
do
    tempString="$vTitle:$vAuthor:$vPrice:$vStock:$vSold"
    #echo "$tempString"
    while [ "$iTitle" == "$vTitle" ]; do
        ./testcase.sh

    done 

done < $INPUT

Testcase.sh contains a script for a sub-menu. When I run this script, my sub-menu keeps repeating, as in a recursive loop. Any idea how to solve this issue? EDIT# Sorry guys $iTitle contains user-input. And a sample of testcase.sh as follows:

#! /bin/bash
menu=""
until [ "$menu" = "f" ]; do
echo "  a.) Update title"
echo "  b.) Update author"
echo "  c.) Update price"
echo "  d.) Update quantity available"
echo "  e.) Update quantity sold"
echo "  f.) Back to main menu"
echo " Make selection"
read menu
case $menu in
a)
echo "a" ;;
b)
echo "b" ;;
c)
echo "c" ;;
d)
echo "d" ;;
e)
echo "e" ;;
f)
break ;;
*) ;;
esac
done

I realised my question isn't clear. I've got a user input $iTitle the first code excerpt checks lookup.txt for the same $vTitle. When successful I want the program to run the testcase.sh. Currently it does run, but testcase.sh runs recursively.

What is the value of $iTitle? I do not see it defined anywhere in the sample code... — nabrond
– nabrond, Commented Feb 1, 2014 at 16:01
please update your question to include what is inside testcase.sh (or small example that simulates the problem). If it's code that uses the shell's select keyword, you can try sourcing the file instead, . ./testcase.sh, but if it has a shebang header, you may need to remove that. Lots of other stuff comes to mind. Lets see what's in ./testcase.sh first ;-) . good luck. — shellter
– shellter, Commented Feb 1, 2014 at 16:02
you mean infinite loop don't you? A recursive function may conceptually call itself for infinity, but in a computer, fn_a->fn_a->fn_a->INF will run out of computer resources pretty quickly and crash. An infinite loop as the result of while condition always being true means the same block is exectued over and over again, but with building up a "stack" of calls and doesn't keep consuming more and more computer resources; just your time ;-). Good luck. — shellter
– shellter, Commented Feb 1, 2014 at 16:26

Sakthi Kumar · Accepted Answer · 2014-02-01 16:12:32Z

1

while [ "$iTitle" == "$vTitle" ]; do
        ./testcase.sh
done

In this block statement, neither $iTitle nor $vTitle changes. and thats why the loop doesn't end. May be you want to replace it with

if [ "$iTitle" == "$vTitle" ]; then
            ./testcase.sh
fi

And also, could not see a value for$iTitle in the code.

edited Feb 1, 2014 at 16:12

answered Feb 1, 2014 at 16:04

Sakthi Kumar

3,04517 silver badges28 bronze badges

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

2 Comments

seelani Over a year ago

:) $iTitle is a user input. So in other words I don't want either $iTitle/$vTitle to change i want to compare them. But while comparing them I hit a recursive loop.

Sakthi Kumar Over a year ago

the comparison is done in while loop, which loops until the expression becomes false, in this case, say if both the values match, then the loop never ends.

Collectives™ on Stack Overflow

Infinite loop while scripting case statement in bash

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related