Date: Mon May 30 15:44:28 EDT 1994
X-Version: 2.6

6.5)  Identifying your Unix flavor.

      This section lists a number of things you can look at in
      attempting to identify the base flavor of your Unix.  Given the
      significant exchange of code and ideas between the various
      flavors and the many changes made by vendors, any statement such
      as "this Unix is an SVR2" is at best a statistical statement
      (except for some SVRn ports).  Also many Unices offer most of
      both worlds (either mixed as in SunOS or strictly separated as in
      Apollo?).  So this section is perhaps not very useful...

      The list of features in previous sections can also help.  For
      example, if a system has a poll(2) but no select(2), it is highly
      probable that it is derived from SVR3.  Also the name of the OS
      can provide a clue, as well as the logon message (e.g.  SGI's
      "IRIX SVR3.3.2") or the output of "uname -a" command.  Available
      commands can also provide hints but this is probably less
      reliable than kernel features.  For example, the type of terminal
      initialization (inittab or ttys) is a more reliable indicator
      than the print subsystem.

      Feature           Typical in SVRx         Typical in xBSD

      kernel name       /unix                   /vmunix
      terminal init     /etc/inittab            /etc/ttys (only getty to 4.3)
      boot init         /etc/rc.d directories   /etc/rc.* files
      mounted FSs       /etc/mnttab             /etc/mtab
      usual shell       sh, ksh                 csh, #! hack
      native FS         S5 (blk: 512-2K)        UFS (blk: 4K-8K)
                        file names <= 14 bytes  file names < 255 bytes
      groups            need newgrp(1)          automatic membership
                        SVR4: multiple groups
      print subsystem   lp, lpstat, cancel      lpr, lpq, lprm (lpd daemon) ??
      terminal control  termio, terminfo,       termios (sgtty before 4.3reno)
                        SVR4: termios (POSIX)   termcap
      job control       >= SVR4                 yes
      ps command        ps -ef                  ps -aux
      multiple wait     poll                    select
      string fcns       memset, memcpy          bzero, bcopy
      process mapping   /proc  (SVR4)

      As we move to the late '90s, this is probably less and less relevant.