How to use an environment variable inside a quoted string in Bash

Question

I\'ve tried various forms of the following in a bash script:

#!/bin/bash
svn diff $@ --diff-cmd /usr/bin/diff -x \"-y -w -p -W $COLUMNS\"

B

Answer 1

The following script works for me for multiple values of $COLUMNS. I wonder if you are not setting COLUMNS prior to this call?

#!/bin/bash
COLUMNS=30
svn diff $@ --diff-cmd /usr/bin/diff -x "-y -w -p -W $COLUMNS"

Can you echo $COLUMNS inside your script to see if it set correctly?