CODEWITHSUNDEEP
linuxbashshellsed
rizvaughan
rizvaughan

Reputation: 33

How to get just numerical value from a string in bash

I have an xml file and i want to extract just the numerical value from a string in the file.One of the solution i came up with is 

cat file.xml |grep -i "mu "| grep -o '[0-9]'

But i get each digit separated by new line,e.g for 100,i get 1 then new line,then 0 and so on.The other solution i came up with is 

cat file.xml |grep -i "mu "|cut -d ' ' -f 4| tr '=' ' '|cut -d ' ' -f2|tr '""' ' '|sed -e 's/^ *//g' -e 's/ *$//g'

My question: Is there a simpler solution to this problem that i get just a numerical value from a line without caring about fields and not to use cut or tr commands?

Upvotes: 3

Views: 3494

Answers (3)

petrus4
petrus4

Reputation: 614

I would encourage avoidance of XML as a format, personally; at least for your own use. Instead of "<mu value="100" />", you could use the following:-

# Name your data file ma-me-mo-mu.txt

100+200+300+400

and then:-

while IFS='+' read ma me mo mu
do
echo "${ma}"
echo "${me}"    
echo "${mo}"
echo "${mu}"
done

You don't need to name your columns inside the data file itself. They go in the file name.

Upvotes: 0

iruvar
iruvar

Reputation: 23364

One option you have is to delete everything that is not a digit from your input

tr -cd '[:digit:]'

Or for floating numbers

tr -cd '[:digit:].'

Upvotes: 0

anubhava
anubhava

Reputation: 785098

Use this egrep:

egrep -o '[0-9]+'

Upvotes: 4

Related Questions