Checking numeric value

Shell Programming and Scripting
1

Hi,

How can I check numeric value in shell?

I am passing one parameter (integer) and I want to restrict any other characters except 0-9.

./script xyz 10

Here 2nd parameter (10) should be integer only.

Can anyone help on this?

Malay

2 
if [[ ! -z $(echo $2 | sed 's/[0-9]//g') ]]
then
echo "integer only"; exit
fi

should work

3 
#echo "1234"  | awk '/^[0-9]+$/' 
1234
#echo "12sasd34"  | awk '/^[0-9]+$/'
#
4

Here's an oneliner:

awk -v x=$a 'END{if(x==x+0) print "integer"}' /dev/null

In this example , a is shell variable.
If a=10, then the output of above is "integer"
If a="10abhishek", then the output of above is ""

5

I want get system open file table value , Can u help.

Thanking you,
Mahesh

6

With bash (extglob option must be on) and ksh :

if [[ "$var" != +([0-9]) ]]
then
   echo "Not an Integer"
fi

Jean-Pierre.

7 
case $2 in
  *[^0-9]*) echo not integer; exit 1 ;;
esac