MSH(8)                                                                  MSH(8)



NAME
       msh - the message shell, explain why a login is frozen

SYNOPSIS
       msh [default]
       msh -h
       msh -V

DESCRIPTION
       When  a  login  is  going  to  be  removed from the system (or moved to
       another system) the  message  shell  presents  notification  to  anyone
       accessing the system from the defunct account.  This is accomplished by
       setting the shell of the account to the path to msh.

       The message is recovered from a spool directory (/var/spool/msh) by the
       login name, the primary login group name, the default parameter, or the
       basename of message shell program path, for the  fixed  name  "Default"
       which ever is first and available via open(2).

       If  no  message  can be located, an internal message directing the cus-
       tomer to the system administrator is displayed.

OPTIONS
       Since the message shell is usually  run  from  login  no  command  line
       switches may be presented.

       -h
              Print only a brief help message.

       -V
              Show only the standerd version banner.

EXAMPLES
       Build  a  file  "toor"  in  the default message spool directory, make a
       login "toor" in /etc/passwd with /usr/local/libexec/msh  as  its  login
       shell and login.

BUGS
       Uses  cat to present the message to the user.  A shell-safe pager would
       be a better option.

       The three second sleep is handy for xterm(1) and xdm(1) logins, but may
       be too short for long messages.

NOTES
       Do  not  put  this  shell  in /etc/shells, as that allows access to the
       account via FTP.  See also the nologin program under some BSD  systems,
       which is polite but less informative.

       If  you  build a link to the program named "ftpshell", that link may be
       placed in /etc/shells to allow FTP-only access to a host, thus  replac-
       ing ftpshell.

       Using  file permissions to trick the open(2) of the message to skip one
       is not as clever as you might believe.  Most group messages  should  be
       world  readable,  personal messages should direct the Customer to see a
       person (never use the spool as a secure communications channel).

AUTHOR
       KS Braunsdorf
       shell @ ksb.npcguild.org.noSpam-please

SEE ALSO
       sh(1), login(8), cat(1), nologin(8l)



                                     LOCAL                              MSH(8)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | BUGS | NOTES | AUTHOR | SEE ALSO