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Non Numeric Check

Terminal - Non Numeric Check
if [ -z $(echo $var | grep [0-9]) ]; then echo "NON NUMERIC"; fi
2009-06-04 07:41:26
User: AnusJenkins
Functions: echo grep
2
Non Numeric Check

use to execute a block of code only if $var is numeric

Alternatives

There are 10 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

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What others think

Hmm... It doesn't really check if a variable is numeric or not, if just tells if there's a digit in there. I wouldn't consider "d42d" numeric. Change the test to this:

if [ -z $(echo $var | grep "^[0-9]\+$") ]; then echo "NON NUMERIC"; fi

Now, it will return "NON NUMERIC" for things like "d42", "4d2", "42d"

Comment by flatcap 282 weeks ago

Ah, sorry, I have it mislabeled. It should be "execute a block of code only if $var is NON-numeric." However, flatcap, I also like your code too, perhaps it is more useful; I was just performing a bunch of ops on my computer that needed to determine if a number was purely non-numeric and included what I used.

Comment by AnusJenkins 281 weeks and 6 days ago

If you don't need a block, that is a good way:

( echo $var | grep -q '[^0-9]' ) && echo "NON NUMERIC"

...and the -q makes a better clean output.

Comment by aurium 281 weeks and 6 days ago

Your point of view

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