cp + not want to overwrite permissions

Question

How to use cp command without to overwrite target file permissions

for example

cp /tmp/file   /home/file

I dont want to change chown and chgrp on /home/file

Answer 1

If you've only opened the manual for cp...

The next will not overwrite the file permissions and ownership + groupship:

cp --no-preserve=mode,ownership /tmp/file /home/file

Note that root privileges are needed if you want to preserve the ownership and groupship.

An excerpt from the manual:

  --preserve[=ATTR_LIST]
      preserve   the   specified   attributes   (default:  mode,owner-
      ship,timestamps), if possible  additional  attributes:  context,
      links, xattr, all

Answer 2

cat will work, too:

cat /tmp/file > /home/file

Answer 3

Or you can use even better install program from GNU coreutils that has been made for this particular purpose. Please note it is not able to recurse (no -R or -r option).

http://www.gnu.org/software/coreutils/manual/html_node/install-invocation.html