**********************************************************************
*
* Function:
* --------
*
*   This routine is attach_exec()ed to or spawn()ed to from a
*   non-superuser caller (unless UID 0 is logging on).
*
*   It receives an open master and slave pseudo-TTY pair as input.
*   It sets up file descriptors 0/1/2 as usual, sets up several
*   environment variables, fork/exec()s /bin/fomtlinc to do the utmpx
*   recording, and than exec()s to the shell.
*

* Parameters:
* ----------
*
*   1:IN      argc -- usual main() parameter
*
*              = 17 -- normal version
*
*
*
*   2:IN      argv -- usual main() parameter
*
*               note: all arguments are the usual NULL-terminated C/370
*                     strings
*

*          max
*          len  argument   description
*          ---  --------   -------------------------------------------
*
*           15  argv[0]  = program name
*
*                          "fomtlinp"
*
*
*           16  argv[1]  = magic number string (to prevent accidental
*                          invocation from shell command line)
*
*                          "*4OurhrEa)R0,H/h"   (required value)

*           47  argv[2]  = message catalog name for catopen()
*
*                          Empty string means use the default message
*                          catalog ="fomcmcat.cat".
*
*                          catopen() will supply the full path
*                          name by looking at any inherited settings
*                          for LC_MESSAGES, NLSPATH, etc. (note that
*                          catopen() is issued with the NL_CAT_LOCALE
*                          parameter.)
*

*           --  argv[3]  = message catalog set for catopen()
*
*                          "0" means to use the default catalog set,
*                          which is 2
*
*
*           --  argv[4]  = master pseudo-TTY file descriptor
*
*                          The correct value is required, if the master
*                          TTY file descriptor is open in the
*                          spawned process.  If the master TTY is
*                          closed (perhaps because FD_CLOEXEC was set),
*                          this parameter must be the number of some
*                          closed file descriptor.
*
*
*           --  argv[5]  = slave pseudo-TTY file descriptor
*
*                          (correct value is required -- must be open)
*
*
*           --  argv[6]  = highest used file descriptor
*
*                          (This value is used only if fcntl(F_CLOSFD)
*                          fails (perhaps because one of the file
*                          descriptors was opened by an authorized
*                          program, etc.).  fomtlinp will then close
*                          (one-by-one) all file descriptors from 3 to
*                          argv[6] + argv[7] onclusive.)
*
*                          This argument should not be needed by anyone
*                          other than the TSO/E OMVS command.

*           --  argv[7]  = extra file descriptors to close
*
*                          (This value is used only if fcntl(F_CLOSFD)
*                          fails (perhaps because one of the file
*                          descriptors was opened by an authorized
*                          program, etc.).  fomtlinp will then close
*                          (one-by-one) all file descriptors from 3 to
*                          argv[6] + argv[7] inclusive.)
*
*                          This argument should not be needed by anyone
*                          other than the TSO/E OMVS command.

*           --  argv[8]  = debug level
*
*                          controls whether or not (hidden) debug
*                          messages are sent to the TTY slave file
*                          descriptor or STDERR (after it has been
*                          set up).  These messages contain debug
*                          information, but are backspaced over and
*                          overwritten with blanks, so they would not
*                          usually appear on the screen.  They will
*                          appear in traces, etc.  This option is
*                          meant to work in conjunction with TSO/E
*                          OMVS command debug mode.
*
*                          0 = don't do any debug recording
*                          1 = don't do any debug recording
*                          2 = don't do any debug recording
*                          3 = don't do any debug recording
*
*                          4 = do debug recording, with overwriting
*                              to hide message on display screen
*
*                          5 = do debug recording, but don't try to
*                              overwrite the debug text on the screen
*
*                          6 = do debug recording to syslog

*           --  argv[9]  = screen width for debug messages
*
*                          This value should be set to the width of
*                          the display screen, if the debug level is
*                          set to 4.  It is used when backspacing and
*                          erasing the debug messages.
*
*                          This value may be set to 0, if the debug
*                          level is not 4.
*
*
*           31  argv[10] = remote hostname (or null) -- only 15
*                          bytes of this will fit into the utmpx
*                          entry

*          255  argv[11] = text for TERM environment variable
*
*                          TERM is not set, if this is an empty
*                          string ("").
*
*
*           15  argv[12] = text for ROWS environment variable
*
*                          ROWS is not set, if this is an empty
*                          string ("").
*
*
*           15  argv[13] = text for COLUMNS environment variable
*
*                          COLUMNS is not set, if this is an empty
*                          string ("").

*           47  argv[14] = path name for SETUID utmpx recording
*                          routine
*
*                          Empty string ("") means use the default
*                          path, which is "/bin/fomtlinc"
*
*
*           15  argv[15] = program name for SETUID utmpx recording
*                          routine
*
*                          Empty string ("") means use the default
*                          program, which is "fomtlinc"
*
*
*           --  argv[16] = SIGCHLD reset flag
*
*                          1 = SIGCHLD will be reset to the default
*                              handling  (This value should seldom
*                              (if ever) be needed -- the main
*                              purpose in the past was to be sure
*                              that NOCLDSTOP was off.)
*
*                          0 = SIGCHLD handling will not be changed
*

*      Other expected input conditions:
*      -------------------------------
*
*      1) Slave TTY must be open, with no controlling terminal
*         established yet.
*
*
*      2) All signals (except perhaps SIGCHLD) should be in their
*         default handling state, before this routine is called.
*         It is OK for signals to be blocked when this routine is
*         called, however.
*
*      3) Any environment variables other than NLSPATH, LC_SYNTAX,
*         LC_MESSAGES, LC_CTYPE, and LC_COLLATE will be passed through
*         to the invoked shell.  The environment variables named here
*         will be gotten rid of before the shell is called.  They
*         will control message catalog processing before the shell is
*         invoked.
*
*      4) Little validity checking is done on the parameters, which
*         are expected to be correct.  This command is not designed to
*         be run from the shell command line.
*
*
*
* Return Value: Does not return to caller
* ------------
*
*
* Non-returning Exits: Does not return to caller
* -------------------