Fast Concatenation of Multiple GZip Files

Question

I have list of gzip files:

file1.gz
file2.gz
file3.gz

Is there a way to concatenate or gzipping these files into one gzip file with

Answer 1

Just use cat. It is very fast (0.2 seconds for 500 MB for me)

cat *gz > final
mv final final.gz

You can then read the output with zcat to make sure it's pretty:

zcat final.gz

I tried the other answer of 'gz -c' but I ended up with garbage when using already gzipped files as input (I guess it double compressed them).

PV:

Better yet, if you have it, 'pv' instead of cat:

pv *gz > final
mv final final.gz

This gives you a progress bar as it works, but does the same thing as cat.