Question

What is the difference between “cvs update” and “cvs -n update”?

I couldn’t understand the difference between them.

Answer 1

The difference is that

cvs update

does an actual update, while

cvs -n update

simulates an update and won’t change anything on disk. It will only show which files would be updated if you did an actual update.

Quoting the CVS documentation (for version 1.12.13):

`-n'
     Do not change any files.  Attempt to execute the `cvs_command',
     but only to issue reports; do not remove, update, or merge any
     existing files, or create any new files.

     Note that CVS will not necessarily produce exactly the same output
     as without `-n'.  In some cases the output will be the same, but
     in other cases CVS will skip some of the processing that would
     have been required to produce the exact same output.