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The downloads on this page, e.g. of NetCDF C/C++/Fortran 4.1.3, show tar.Z and tar.gz formats. The tar.Z doesn't even have a configure file in it. What is it used for?

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up vote 12 down vote accepted

.Z files are compressed with the older compress utility while .gz are compressed with gzip.

Some ancient systems might be missing gzip/gunzip so will use uncompress and .Z files.

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However, one should not just rely on the name! Use the file program to determine the real type of the file. – rozcietrzewiacz Jul 29 '11 at 6:43
Some very, very, VERY ancient systems that haven't seen an update in two decades... – Shadur Jul 29 '11 at 11:20
That's what I meant with ancient. For example Solaris 7 11/99 was the last Solaris release not bundling gzip. – jlliagre Jul 29 '11 at 13:25

This is the right answer. I'l just add that although they are compressed using a different program, gzip/gunzip can decompress .Z archives without any problems.

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