using cut command

UNIX for Beginners Q & A UNIX for Dummies Questions & Answers
1

I am new to unix ... I have a file with name unixile.123761 I need to cut the extension from this file name? can u help me for this

i have tried like follows

copied the file lo one variable v

and then `echo $v | grep cut -d = -f 1`

2 
#!/bin/ksh
a=unixile.123761
firstpart=${a%%.*}
extension=${a##*.}

firstpart is now unixile, extension is 123761

3

Hi jim,
could you please explain the command. I am new to Unix. I googled it and I could not find much information about curly braces.

Thanks,
Don

4

Those commands are used to split strings of characters into pieces.
You can also use cut, but it will have problems with a filename like mytarball.tar.gz

This page explains how to play with strings in bash (ksh has the same {} syntax for %, %%, #, and ##)
Manipulating Strings

5

The grep in your original post is surplus and will give syntax errors.
I think you meant:

v="unixile.123761"
w=`echo "$v" | cut -d\. -f1`
echo "$w"

unixile
6

v="unixile.123761"
firstpart=`echo "$v" | cut -d '.' -f1`
extpart=`echo "$v" | cut -d '.' -f2`

7

for a in `ls`; do if [ $a != ${a%.} ] ; then mv $a ${a%.}; fi; done

write this in the shell when you are positioned in the directory where you want to make the changes; note that the command {a%.*} is non-greedy - that is the file 'this.is.my.file' will be renamed 'this.is.my', not just 'this'

8

Or alternatively, you can use AWK too..

v="unixile.123761"
ext=`echo $v | awk -F "\." '{ print $2 }'`
echo $ext

In case, if you have file name like mytarball.tar.gz, this code snippet will print "tar".

9 
for a in *