su(1m) is incompatible

[Kjetil Torgrim Homme]

The traditional syntax of su(1m) is like this (quoted from Solaris'
manual page):

     Any additional arguments  given  on  the  command  line  are
     passed to the new shell. When using programs such as sh , an
     arg of the form -c string executes string  using  the  shell
     and an  arg of -r gives the user a restricted shell.

In GNU su(1m), the meaning of -c has been hardcoded.  This is
incompatible with traditional behaviour.  Everything after the
username should be used as the argv for the login shell.  With the
current syntax, it is impossible to do "su user -r" or "su user
-login".


Kjetil T.