Getting number from a string

Shell Programming and Scripting
1

I have a string c12 and want to get the number 12

In general instead of 12 I can have any number. I have to capture the number as I need to do some computations on it.

I am using a bash script

2

Try:

number=`echo $string | tr -d 'a-zA-Z'`
1 Like
3

Using parameter expansion:

bash-4.2$ v=c12
bash-4.2$ echo "${v//[!0-9]}"
12
4

Longhand using cygwin...

AMIGA:~> var="c12fg"
AMIGA:~> echo "${var:1:2}"
12
AMIGA:~> _
5

Some more

$ echo "c12" | tr -cd '[[:digit:]]' 
12

$ echo "c12" | awk 'gsub(/[[:alpha:]]/,x)' 
12
6 
result=`echo $string | egrep -o "[0,9]{1,5}"`
7

if you have Ruby

# number=$(echo "c12" | ruby -e "puts gets.scan(/\d+$/)")
# echo $number
12