What does .tar-1 in a filename obtained by gunzip a tar.gz mean?

Question

I downloaded a zipped tar-file filename.tar.gz and after converting it with the gunzip command it is now named filename.tar-1. What does the -1 mean?

Answer 1

You would see this behavior if your gunzip is aliased to gunzip -N and the original file name was filename-1. To illustrate:

$ ls
filename-1
$ gzip filename-1

$ mv filename-1.gz filename.gz

$ gunzip -Nv filename.gz
filename.gz:     -0.5% -- replaced with filename-1

From man gunzip:

   -N --name
          When  compressing,  always  save the original file name and time
          stamp; this is the  default.  When  decompressing,  restore  the
          original  file  name  and  time stamp if present. This option is
          useful on systems which have a limit on file name length or when
          the time stamp has been lost after a file transfer.