How to get file extension (without the dot) ?

[scls19fr]

Hello,

I would like to know what is the extension of a file

For example
filename="file.txt"

I'd like to put "txt" in a variable called ext

I see in an other post
http://www.linuxforums.org/forum/lin...xtensions.html
echo <filename> | grep -o '\.[^.]*$'

So I think I need to do something like
ext=`echo $filename | grep -o '\.[^.]*$'`

But I don't know how I should modify this to avoid the dot of ".txt"
and to get only "txt" in $ext.


Kind regards

[ghostdog74]

if you are on bash

# a=file.txt
# echo ${a/*./}
txt

[scls19fr]

Thanks a lot
I also have post the same question at
How to get file extension (without the dot) - LinuxQuestions.org
with differents answers

[burschik]

This is Unix. There are many ways to get a thing done. That's why some love it and others hate it.