How do I learn how to get quoting right in bash?

Question

I\'m constantly confused by the rules for quoting and evaluating when I\'m writing bash scripts. I know some of the basics, like the difference between \'\' and \"\" and ``,

Answer 1

At the shell prompt,

set -x
set -v

and create the following python program 'args.py'

#!/usr/bin/env python

import sys
print sys.argv
for arg in sys.argv[1:]:
    for c in arg:
        print c,"|",
    print

Then experiment with command invocations like:

U=hello\ world ; V="-->$U<--"; W="1 $U 2 $V 3"; args.py $W

Until you realize that there is no logical way of thinking about what is going on. It really is all done by capricious magic shell pixies.