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  man pages->HP-UX 11i man pages -> inittab (4)              


 inittab(4)                                                       inittab(4)

 NAME    [Toc]    [Back]
      inittab - script for the boot init process

 DESCRIPTION    [Toc]    [Back]
      The /etc/inittab file supplies the script to the boot init daemon in
      its role as a general process dispatcher (see init(1M)).  The process
      that constitutes the majority of boot init's process dispatching
      activities is the line process /usr/sbin/getty that initiates
      individual terminal lines.  Other processes typically dispatched by
      boot init are daemons and shells.

      The inittab file is composed of entries that are position-dependent
      and have the following format:


      Each entry is delimited by a newline; however, a backslash (\)
      preceding a newline indicates a continuation of the entry.  Up to 1024
      characters per entry are permitted.  Comments can be inserted in the
      process field by starting a "word" with a # (see sh(1)).  Comments for
      lines that spawn gettys are displayed by the who command (see who(1)).
      It is expected that they will contain some information about the line
      such as the location.  There are no limits (other than maximum entry
      size) imposed on the number of entries within the inittab file.

      The entry fields are:

           id        A one- to four-character value used to uniquely
                     identify an entry.  Duplicate entries cause an error
                     message to be issued, but are otherwise ignored.  The
                     use of a four-character value to identify an entry is
                     strongly recommended (see WARNINGS below).

           rstate    Defines the run level in which this entry is to be
                     processed.  Run levels correspond to a configuration of
                     processes in the system where each process spawned by
                     boot init is assigned one or more run levels in which
                     it is allowed to exist.  Run levels are represented by
                     a number in the range 0 through 6.  For example, if the
                     system is in run level 1, only those entries having a 1
                     in their rstate field are processed.

                     When boot init is requested to change run levels, all
                     processes that do not have an entry in the rstate field
                     for the target run level are sent the warning signal
                     (SIGTERM) and allowed a 20-second grace period before
                     being forcibly terminated by a kill signal (SIGKILL).
                     You can specify multiple run levels for a process by
                     entering more than one run level value in any
                     combination.  If no run level is specified, the process
                     is assumed to be valid for all run levels, 0 through 6.

 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003

 inittab(4)                                                       inittab(4)

                     Three other values, a, b and c, can also appear in the
                     rstate field, even though they are not true run levels.
                     Entries having these characters in the rstate field are
                     processed only when a user init process requests them
                     to be run (regardless of the current system run level).
                     They differ from run levels in that boot init can never
                     enter "run level" a, b, or c.  Also, a request for the
                     execution of any of these processes does not change the
                     current numeric run level.

                     Furthermore, a process started by an a, b, or c option
                     is not killed when boot init changes levels.  A process
                     is killed only if its line in inittab is marked off in
                     the action field, its line is deleted entirely from
                     inittab, or boot init goes into the single-user state.

           action    A keyword in this field tells boot init how to treat
                     the process specified in the process field.  The
                     following actions can be specified:

                     boot              Process the entry only at boot init's
                                       boot-time read of the inittab file.
                                       Boot init starts the process, does
                                       not wait for its termination, and
                                       when it dies, does not restart the
                                       process.  In order for this
                                       instruction to be meaningful, the
                                       rstate should be the default or it
                                       must match boot init's run level at
                                       boot time.  This action is useful for
                                       an initialization function following
                                       a hardware boot of the system.

                     bootwait          Process the entry only at boot init's
                                       boot-time read of the inittab file.
                                       Boot init starts the process, waits
                                       for its termination, and, when it
                                       dies, does not restart the process.

                     initdefault       An entry with this action is only
                                       scanned when boot init is initially
                                       invoked.  Boot init uses this entry,
                                       if it exists, to determine which run
                                       level to enter initially.  It does
                                       this by taking the highest run level
                                       specified in the rstate field and
                                       using that as its initial state.  If
                                       the rstate field is empty, boot init
                                       enters run level 6.

 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003

 inittab(4)                                                       inittab(4)

                                       The initdefault entry cannot specify
                                       that boot init start in the singleuser
 state.  Additionally, if boot
                                       init does not find an initdefault
                                       entry in inittab, it requests an
                                       initial run level from the user at
                                       boot time.

                     off               If the process associated with this
                                       entry is currently running, send the
                                       warning signal (SIGTERM) and wait 20
                                       seconds before forcibly terminating
                                       the process via the kill signal
                                       (SIGKILL).  If the process is
                                       nonexistent, ignore the entry.

                     once              When boot init enters a run level
                                       that matches the entry's rstate,
                                       start the process and do not wait for
                                       its termination.  When it dies, do
                                       not restart the process.  If boot
                                       init enters a new run level but the
                                       process is still running from a
                                       previous run level change, the
                                       process is not restarted.

                     ondemand          This instruction is really a synonym
                                       for the respawn action.  It is
                                       functionally identical to respawn but
                                       is given a different keyword in order
                                       to divorce its association with run
                                       levels.  This is used only with the
                                       a, b, or c values described in the
                                       rstate field.

                     powerfail         Execute the process associated with
                                       this entry only when boot init
                                       receives a power-fail signal (SIGPWR
                                       see signal(5)).

                     powerwait         Execute the process associated with
                                       this entry only when boot init
                                       receives a power-fail signal (SIGPWR)
                                       and wait until it terminates before
                                       continuing any processing of inittab.

                     respawn           If the process does not exist, start
                                       the process; do not wait for its
                                       termination (continue scanning the
                                       inittab file).  When it dies, restart
                                       the process.  If the process

 Hewlett-Packard Company            - 3 -   HP-UX 11i Version 2: August 2003

 inittab(4)                                                       inittab(4)

                                       currently exists, do nothing and
                                       continue scanning the inittab file.

                     sysinit           Entries of this type are executed
                                       before boot init tries to access the
                                       console.  It is expected that this
                                       entry will be only used to initialize
                                       devices on which boot init might
                                       attempt to obtain run level
                                       information.  These entries are
                                       executed and waited for before

                     wait              When boot init enters the run level
                                       that matches the entry's rstate,
                                       start the process and wait for its
                                       termination.  Any subsequent reads of
                                       the inittab file while boot init is
                                       in the same run level cause boot init
                                       to ignore this entry.

           process   This is a sh command to be executed.  The entire
                     process field is prefixed with exec and passed to a
                     forked sh as "sh -c 'exec command'".  For this reason,
                     any sh syntax that can legally follow exec can appear
                     in the process field.  Comments can be inserted by
                     using the ; #comment syntax.

 WARNINGS    [Toc]    [Back]
      The use of a four-character id is strongly recommended.  Many pty
      servers use the last two characters of the pty name as an id.  If an
      id chosen by a pty server collides with one used in the inittab file,
      the /etc/utmp file can become corrupted.  A corrupt /etc/utmp file can
      cause commands such as who to report inaccurate information.

 FILES    [Toc]    [Back]
      /etc/inittab        File of processes dispatched by boot init.

 SEE ALSO    [Toc]    [Back]
      sh(1), getty(1M), exec(2), open(2), signal(5).

 Hewlett-Packard Company            - 4 -   HP-UX 11i Version 2: August 2003
[ Back ]
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