Re: [Sheflug] Thanks and WVDial permissions

["Stephen J. Turnbull" <nospam [at] sk.tsukuba.ac.jp>]

>>>>> "Keith" == Keith Powell <Keithp [at] g4jvx.screaming.net> writes:

    Keith> to do this. I can't find it in YAST, and have come to the
    Keith> conclusion that I

Al Hudson will tell you that it must be there because GUIs are great.

I, however, am not surprised.

Having had my fun, I'll try to be helpful now :-)

Please send the YAST developers a bug report; they either need to put
the feature in, or make it more accessible.

    Keith> use the "change group" command by going to the KDE terminal
    Keith> as root, and typing:

    Keith>   chgrp dialout /etc/ppp/pap-secrets

    Keith> I then repeat this for chap-secrets.

    Keith> Could you kindly tell me if this is correct, please, or if
    Keith> I am completely wrong.

This is correct.  You could do it in one operation:

	       chgrp dialout /etc/ppp/{ch,p}ap-secrets

You could do it with chown:

	       chown .dialout /etc/ppp/{ch,p}ap-secrets

but these are just variations on your theme.

Warning: on many systems only root can change the ownership of a file
to a group it is not a member of.  _You_ can and _should_ verify that
everything is OK by doing

ls -l /etc/ppp/{ch,p}ap-secrets
chgrp dialout /etc/ppp/{ch,p}ap-secrets
ls -l /etc/ppp/{ch,p}ap-secrets

(until you are confident).  I still do this (and similar checks) on
*nix systems that are not Debian Linux, because there are always
variations in the "gotchas".

One special case you need to know about is the symbolic link.  If
/etc/ppp/pap-secrets was in fact a symbolic link (very unlikely for
this particular file), then its authorization data will always show up
as

lrwxrwxrwx   1 someuser somegrp

These cannot be changed with chown, chgrp, or chmod, because these
functions "chase symlinks" and operate on the authorization data in
the real directory entry.  (It is possible to have several different
sets of authorization data for the same file by using "hard" links.)

Try it (you can paste this to a file and source it from bash):

su # so that the ownership will be known and permissions for
   # operations will surely be enough
# with symlinks
touch my-real-file
ln -s my-symbolic-link my-real-file
ls -l my-*
chgrp users my-symbolic-link # I think most systems have a users group
                             # the group must exist
ls -l my-*
rm -f my-*
# now with hard links
touch my-real-file
ln my-ordinary-link my-real-file
ls -l my-*
chgrp users my-ordinary-link # I think most systems have a users group
                             # the group must exist
ls -l my-*
rm -f my-*

Exercise for the reader:  in each case, what happens if you rm(1) one of
the file's directory entries but not the other?

All the above should fit on one screen, so you can compare the changes
that happen for the differnt kinds of link.

HTH

-- 
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Institute of Policy and Planning Sciences       Tel/fax: +81 (298) 53-5091
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