Shell Programming and Scripting

ah solvered already, wouldn't read about it!

echo "abc12345" | tr -cd [a-z]+[A-Z]

thanks anyway

Code:

echo "abc12FG345" | tr -cd [:alpha:]

--this may also work. I am not at my system. So cant test it.Check this link -
tr command

I'm confused here... do you want to retain the alphabets or remove them in that example?
I'll give a couple of examples:

Code:

# echo abc123$%^|tr -cd [:alpha:]
abc#
# echo abc123$%^|tr -d [:alpha:]
123$%^
#

So what the first tr does is delete all elements (-d) that are in the complement set (-c) as that of alpha. This means that anything that is not an alphabet (upper/lower case) will be removed. In the second, no complements are used, so tr will delete all elements that are in the alpha set.

I think, in the first part of the question, it was to retain only numbers and then nortypig wanted to retain 2 sets of patterns - [a-z]+[A-Z], both uppercase and lowercase letters. That was my understanding..