Windows only allows to set the primary group to a group already
present in the TOKEN_GROUP list. Cygwin OTOH fakes success at
setgid() time, to allow a subsequent call to setuid() to do
the actual account switching. To have a sane behaviour in the
command line tool, check group membership and disallow to switch
to groups other than those already present in the user token.
Fixes: 8bd56ec873 ("Cygwin: newgrp: first full version")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Fix an error message accessing argv[1] even after it has been
potentially moved. Print group name from group DB instead.
Fixes: 8bd56ec873 ("Cygwin: newgrp: first full version")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- add '-' option
- make group argument optional
- drop ability to take a numerical group argument
- simplify usage output to bare minimum
- Add manpage and documentation
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This tool allows to change the primary group for a child process.
The new primary group MUST be part of the supplementary group list
of newgrp's user token.
The command started as child process is specified on the command line.
If it's missing, start the user's default shell with the new primary
group.
TODO: Implement '-' option.
Add command description to documentation.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Corinna Vinschen