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Check if variable is a number

Terminal - Check if variable is a number
if [[ "$1" =~ ^[0-9]+$ ]]; then echo "Is a number"; fi
2013-02-15 19:05:34
User: Vilemirth
Functions: echo
1
Check if variable is a number

Alternatives

There are 6 alternatives - vote for the best!

Terminal - Alternatives
if [ "$testnum" -eq "$testnum" 2>/dev/null ]; then echo It is numeric; fi
2009-10-09 14:57:27
User: jgc
Functions: echo
0

Using the standard numeric comparison but suppressing the STDERR output acts as the simplest way to check a value is numeric. See sample output for some examples.

(($1 > 0)) && echo "var is a number"
2013-03-22 01:15:00
User: khayyam
Functions: echo
0

calculate if "$1" is a number ... decimals included :)

echo $X | egrep "^[0-9]+$"

Know a better way?

If you can do better, submit your command here.

What others think

Regex does not handle decimals, i.e. 1.0

Comment by zlemini 87 weeks and 1 day ago

Your point of view

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