What does SUID, SGID and Sticky bits do on inappropriate files?

[Neil Rickert]

In article <1990Dec25.032451.25017 at gpu.utcs.utoronto.ca> jmason at gpu.utcs.utoronto.ca (Jamie Mason) writes:
>	Also what are the effects of the Set-User-ID and Set-Group-ID
>bits on files which cannot be properly said to be *EXECUTED*?  (Though the X
>permissions are set)   For instance Directories, but also the other types
>of special files named above?
>
 Recent versions of 'sendmail' use the suid/sgid bits when mailing to a
file.  That is, when an alias in your aliases file (or in a user .forward)
lists a file name to which mail is to be appended.  In that case 'sendmail'
uses the owner and/or group of the file while writing.  Note that the suid
and/or sgid bits must be set, but NO execute bits may be set for this to
work.  'sendmail' refuses to mail to a file with any execute bits set.

 (Observed behavior documented in the source code of sendmail-5.64,5.65)


-- 
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
  Neil W. Rickert, Computer Science               <rickert at cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115                                   +1-815-753-6940