inittab(4)						     Kernel Interfaces Manual							inittab(4)

NAME

       inittab - script for the boot process

DESCRIPTION

       The  file  supplies the script to the boot daemon in its role as a general process dispatcher (see init(1M)).  The process that constitutes
       the majority of boot process dispatching activities is the line process that initiates individual terminal lines.   Other  processes  typi-
       cally dispatched by boot are daemons and shells.

       The 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 charac-
       ters 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  are  displayed by the 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 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 is assigned one or more run levels in which it is allowed to exist.  Run
			levels are represented by a number in the range through For example, if the system is in run level only those entries hav-
			ing a in their rstate field are processed.

			When  boot  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 and allowed a 20-second grace period before being forcibly terminated by a kill sig-
			nal 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, through

			Three other values, and 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 process requests them to be run (regardless of the
			current system run level).  They differ from run levels in that boot can never enter "run level" or 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 or option is not killed when boot changes levels.  A process is killed only if its
			line in is marked in the action field, its line is deleted entirely from or boot goes into the single-user state.

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

			Process the entry only at boot
					  boot-time  read  of  the  file.  Boot 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 run level at boot time.  This action is useful for an initializa-
					  tion function following a hardware boot of the system.

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

			An entry with this
					  action is only scanned when boot is initially invoked.  Boot 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 field
					  and using that as its initial state.	If the rstate field is empty, boot enters run level

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

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

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

			This instruction is really a synonym for the
					  action.   It is functionally identical to but is given a different keyword in order to divorce its asso-
					  ciation with run levels.  This is used only with the or values described in the rstate field.

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

			Execute the process associated with this entry only when boot
					  receives a power-fail signal and wait until it terminates before continuing any processing of

			If the process does not exist, start the process;
					  do not wait for its termination (continue scanning the file).  When it dies, restart	the  process.	If
					  the process currently exists, do nothing and continue scanning the file.

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

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

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

WARNINGS

       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 file, the file can become corrupted.  A corrupt file can cause  commands  such  as	to
       report inaccurate information.

FILES

       File of processes dispatched by boot

SEE ALSO

       sh(1), getty(1M), exec(2), open(2), signal(5).

																	inittab(4)