UNIX for Dummies Questions & Answers

Hi,

I have a .txt file and it contains some file names.I want to append .gz extension to all the file names that are present within the .txt file.

Input.

aa.bb.Mar-20-2007
aa.cc.Mar-20-2007

Output

aa.bb.Mar-20-2007.gz
aa.cc.Mar-20-2007.gz

Please help me with this command.

Thanks,
Kumar

Try this..
But not sure from your desc that the input file contains only filenames..

awk '{print $0".gz" }' original_file.txt > temp_file
mv temp_file original_file.txt

If the input file contains other data besides the filenames, the below one will look for only those patterns which you mentioned above and rename it with .gz ext..

sed 's/\(.*\)\(-[0-3][0-9]-\)\([0-9]\{4\}\)/\1\2\3.gz/' original_file.txt > temp_file
mv temp_file original_file.txt

Hi Jacoden,

Your first command with Awk is working perfectly fine.Can you please explain the awk and sed command with u had used.

Thanks a lot,
Kumar

awk '{print $0".gz" }' original_file.txt > temp_file

$0 will be each line being processed by awk.So print $0" ".gz" will be a simple
concatanation of each line read from file with string ".gz" and printing it to stdout.


sed 's/\(.*\)\(-[0-3][0-9]-\)\([0-9]\{4\}\)/\1\2\3.gz/' original_file.txt > temp_file

Here, it looks for three pattern
\(.*\) - will look for any number of characters, followed by
(-[0-3][0-9]-\) - pattern like -20- (The date part), followed by
\([0-9]\{4\}\) - pattern like 2004 (or any year between 0000-9999)

And on successful match of the above reg exp,
replace the data with
\1 - will be the data which matched the first pattern.ie,\(.*\)
\2- as the second.ie,\(-[0-3][0-9]-\)
and \3 , the third one.ie,\([0-9]\{4\}\) and followed by string ".gz"

Hope this is clear.

for this example :

Code:

# more file
aa.bb.Mar-20-2007
aa.cc.Mar-20-2007
# sed -i 's/$/\.gz/' file
# more file
aa.bb.Mar-20-2007.gz
aa.cc.Mar-20-2007.gz

Thanks a lot Jacoden for your explanation.