OSF

NAME

inittab − Controls the initialization process

SYNOPSIS

/etc/inittab

DESCRIPTION

The inittab file supplies the init program with instructions for creating and running initialization processes.  The init command reads the inittab file each time init is invoked.  The file typically contains instructions for the default initialization, the creation and control of processes at each run level, and the line process, getty which controls the activation of terminal lines. 

The inittab file is composed of lines, each with four fields; each field is separated by a colon.  There is no limit to the number of lines in the inittab file. The fields are:

Identifier:Runlevel:Action:Command

IndentifierThis is a fourteen character field used to uniquely identify an object. 

RunlevelThis is a twenty character field which defines the run levels in which the object is to be processed. Runlevel corresponds to a configuration of processes in a system. Each process spawned by the init command is assigned one or more run levels in which it is allowed to exist. The run levels are represented by the characters 0, 2, 3, S, and s.  The Runlevel field can define multiple run levels for a process by selecting more than one run level in any combination of Runlevel characters. 

ActionThis is a twenty character field that tells init how to treat the specified process.  init recognizes the following Actions:

respawnIf the process does not exist or dies, init starts it. If the process currently exists, init does nothing and continues scanning the inittab file. 

waitWhen init enters a run level that matches the run level of the entry, it starts the process and waits for its termination.  As long as init continues in this run level, it does not act on subsequent reads of the entry in the inittab file. 

onceWhen init enters a run level that matches the line’s run level, it starts the process and does not wait for its termination.  When the process stops, init does not restart it.  If init enters a new run level where the process is still running from a previous runlevel change, init does not restart the process. 

bootWhen init first executes and reads the inittab file, it processes this entry.  init starts the process and does not wait for its termination.   When the process stops, init does not restart it.  The run level specified in this line entry should be the default run level, or it must match the run level at which init operates at boot time. 

bootwaitWhen init first executes and reads the inittab file, it processes this line entry.  init starts the process, waits for its termination and, when it dies, does not restart the process. 

powerfailWhen init receives the SIGPWR power fail signal, it executes the process associated with this line. 

powerwaitWhen init receives the the SIGPWR power fail signal, it executes the process associated with this line and waits until the process terminates before continuing any processing of the inittab file. 

offIf the process associated with this line is currently running, init sends the warning signal SIGTERM and waits 20 seconds before sending the kill signal SIGKILL. If the process is nonexistent, init ignores the line. 

initdefaultA line with this action is processed when init is originally invoked. init uses this line to determine which run level to enter originally.  It does this by taking the highest run level specified in the run level field and using that as its initial state. If the run level field is empty, this is interpreted as 0s23, so init will enter run level 3. If init does not find an initdefault line in the inittab file, it requests an initial runlevel from the operator. 

sysinitEntries of this type are executed before init tries to access the console. It is expected that this line will be only used to initialize devices on which init might try to request a run level. 

CommandThis is a 1024 character field which holds the sh command to be executed. The entry in the command field is prefixed with exec.  Any legal sh syntax can appear in the command field. Comments can be inserted with the  #comment syntax. The line continuation character \\*O may be placed at the end of a line. 

FILES

/etc/gettySpecifies the command that initializes and controls terminal lines

RELATED INFORMATION

Commands: init(8)

Functions:  kill(2)