egrep syntax question - Shell Programming and Scripting

DKNUCKLES · #1 11-18-2007

I have a (seemingly) simple question for you guys

I need my script to allow users to enter numbers with either 2 decimal points or with no decimal points.

here's the code I have right now for testing, but I can't for the life of me figure out whats wrong!

(it's been broken up into 2 different grep statements)

decimal=10.500
echo $decimal | egrep -q '[0-9+]' && echo success || echo failure
echo $decimal | egrep -q '[0-9+]\.[0-9][0-9]' && echo success || echo failure

any insight would be greatly appreciated as this has been the cause of much frustration for me!

radoulov · #2 11-18-2007

With egrep:

Code:

printf "%s\n" "$decimal"|egrep '^[0-9]+(\.[0-9][0-9])?$' >/dev/null && echo OK||echo KO

Or (with not too old versions):

Code:

printf "%s\n" "$decimal"|egrep -q '^[0-9]+(\.[0-9]{2})?$' && echo OK||echo KO

With bash3(and ksh93?):

Code:

[[ "$decimal" =~ ^[0-9]+(\.[0-9]{2})?$ ]]&&echo OK||echo KO

Of course, you should modify it a bit, if you want
.00 and 00. to be considered OK.

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