UNIX for Dummies Questions & Answers

no, bash should be fine.
are you sure your 'temp_star1' file always has TWO numbers and no empty lines?

Yup, that was it. Obviously I'm just a beginner here! A couple of questions if you have the time.

1)What's the difference between bash and ksh and is one better than the other?

2)if [ "$(echo "if (${a} < ${b}) 1" | bc)" -eq 1 ]
could you explain the above line to me?

Thanks!!

edit: in my case, when I change from bash to ksh I don't get the same error in ksh.

This is the stuff religious wars are made of. There's not a clear winner or everyone would be using one or the other.

KSH is older and more traditional. If you're on a non-Linux system it's likely to have ksh.

BASH and modern enough versions of KSH have most of their string operations in common. They differ in how they use arrays ( ksh uses set -a, BASH uses VAR=( stuff ) )

BASH does not support floating point numbers. Very new versions of ksh do.

they're 2 diff implementations with diff capabilities. I prefer using ksh for scripting and bash for the interactive sessions as ksh has been more widely available.
as ksh doesn't support the floating point arithmetic natively, we have to do the math with the external tool - this case 'bc' (BasicCalculator) that support floating point math. We pipe the boolean expression if (${a} < ${b}) 1 which says: if $a < $b, then return 1. The output from 'bc' is then being compared to '1' and the one of the then/else branches get executed.
strange - there must something else triggering this error in bash. Once again, examine the file you're reading in as previously suggested.