zcat two files


 
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# 1  
Old 09-28-2012
zcat two files

Hi,

Like

Code:
cat file1 file2 > file

Can I do

Code:
zcat file1.gz file2.gz > file.gz

# 2  
Old 09-28-2012
why didn't you try your self ...Smilie

and answer is NO.... you can't create .gz files like this..

if we can, just think what is use of gzip...?????

Last edited by pamu; 09-28-2012 at 04:27 PM..
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# 3  
Old 09-28-2012
Hi Pamu,

Thanks for your advice. I have more than 10 files each of 20GB.

I wanted to confirm before trying it. But, anyways I figured out that you first zcat multiple files into another file and gzipping it rather than directly printing into a gz file. Smilie
# 4  
Old 09-28-2012
You can do cat file1 file2 | gzip > file.gz

...but you can't cat gz files.

You could if you decompressed them I suppose, but that'd have a lot of overhead.
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# 5  
Old 09-29-2012
Quote:
Originally Posted by Corona688
You can do cat file1 file2 | gzip > file.gz

...but you can't cat gz files.
but we can use zcat.

Code:
zcat file_1.gz file_2.gz | gzip > output.gz

EDIT:
tried binlib suggestion and it also works...Smilie
Code:
cat file_1.gz file_2.gz  > output.gz

and we can append data directly into gz file also....
Code:
cat file_3.gz >> output.gz
cat file | gzip >> output.gz


Last edited by pamu; 10-01-2012 at 04:11 AM..
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# 6  
Old 09-29-2012
Actually you CAN cat gz files and the result is a valid gzip file.
This User Gave Thanks to binlib For This Post:
# 7  
Old 10-01-2012
Hi, binlib.
Quote:
Originally Posted by binlib
Actually you CAN cat gz files and the result is a valid gzip file.
Commentt:

My experience is that unzipping the combined file results in the constituent files being effectively catted together.

If that is true, then your observation is correct, but it may not be useful in many situations ... cheers, drl
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