I'm writing a bash script and I need to check if a file name has a number at the end (after a period) and if so get it, but I can't figure out how to use regex on a variable or string.
I was able to use
echo in the terminal to pipe a string into grep, like this:
echo "filename.txt.123" | egrep -o "\.[0-9]+$" | egrep -o "[0-9]+"
But I need to assign the output of this to a variable. I tried doing this:
revNumber= echo "filename.txt.123" | egrep -o "\.[0-9]+$" | egrep -o "[0-9]+"
But that doesn't work. I tried a bunch of other things as well, but nothing was valid.
In my bash script I want to use grep on a variable and not a string, but the concept here is the same.
How can I use grep on a string or variable and then save the result into another variable?