Shell Programming and Scripting

Hi,

I have 2 files with contents in them and I need to compare each item in each file.

File1:
item4
item5

File2:
item2
item3
item5
item6

The items names can be of different lengths.
If the items in the File1 are not in File2,
delete the missing item in File1.

The resulting File1 in the above example should be:
File1:
item5

How can I do this using shell script? Thanks in advance!

no need of shell script, a command can do...

egrep "$(< file2)" file1

Hi, thanks for your help but when I tried to use this command, it say syntax error.

I tried using this command instead:

egrep "(<file2)" file1

but both the contents in file1 is not changed.

$ more file1
item4
item5 hello
item2

$ more file2
item2
item3
item5 hello
item6

$ egrep "$(<file2)" file1
item5 hello
item2

Can you compare the command I have provided and what you typed ??

you are missing "$" symbol... try again.

This is what I get:

% cat file2
item2
item3
item5
item6
% cat file1
item4
item5

% egrep "$(<file2)" file1
Variable syntax


I am using unix to do this command

ah got it... you are using csh shell or something similar....

either change your current shell to ksh or

write a script as :

#!/usr/bin/ksh

egrep "$(<file2)" file1

I use ksh shell as my default

hmm.. but I can't test this command in Unix?