Purpose
Changes records
in the /etc/inittab file.
Description
The chitab command changes a record in the /etc/inittab file.
The Identifier:Run Level:Action:Command parameter string is the new entry to the /etc/inittab file. You can search for a specific record by using
fields in the Identifier portion of the parameter string. The
command finds the specified Identifier and changes that record.
Note: The chitab command can not comment out
an entry in the /etc/inittab file.
Parameters
The Identifier:Run Level:Action:Command parameter string specifies a record in the /etc/inittab file
where the following parameters apply:
| Item |
Description |
| Action |
A 20-character parameter that informs the init command
how to process the Command parameter you specify. The init command recognizes the following actions:
- boot
- Read this record only when the system boots and reads the /etc/inittab file. The init command starts the process.
Do not wait for the process to stop, and when it does stop, do not
restart the process. The run level for this process should be the
default, or it must match the run level specified by the init command at startup time.
- bootwait
- Read this record only when the system boots and reads the /etc/inittab file. The init command starts the process.
Wait for it to stop, and when it does stop, do not restart the process.
- hold
- When the process identified in this record is terminated, do
not start a new one. The hold action can only be activated
by the phold command.
|
| |
- initdefault
- Start the process identified in this record only when the init command is originally invoked. The init command uses
this line to determine which run level to originally enter. It does
this by taking the highest run level specified in the RunLevel field and using that as its initial state. If the RunLevel parameter is empty, this is interpreted as 0123456789, and the init command enters a run level of 9. If the init command does not find an initdefault line in the /etc/inittab file, it requests an initial run level from the operator at initial
program load (IPL) time.
- off
- If the process identified in this record is currently running,
send the warning signal SIGTERM and wait 20 seconds before
sending the SIGKILL kill signal. If the process is nonexistent,
ignore this line.
- once
- When the init command enters the run level specified
for this record, start the process, do not wait for it to stop, and
when it does stop, do not restart the process. If the system enters
a new run level while the process is running, the process is not restarted.
|
| |
- ondemand
- Functionally identical to respawn. If the process identified
in this record does not exist, start the process. If the process currently
exists, do nothing and continue scanning the /etc/inittab file.
Specify this action to perform the respawn action when using a, b, or c run levels.
- powerfail
- Start the process identified in this record only when the init command receives a SIGPWR power fail signal.
- powerwait
- Start the process identified in this record only when the init command receives a SIGPWR power fail signal, and
wait until it stops before continuing to process the /etc/inittab file.
|
| |
- respawn
- If the process identified in this record does not exist, start
the process. If the process currently exists, do nothing and continue
scanning the /etc/inittab file.
- sysinit
- Start the process identified in this record before the init command tries to access the console. For example, you might use
this to initialize devices.
- wait
- When the init command enters the run level specified
for this record, start the process and wait for it to stop. While
the init command is in the same run level, all subsequent reads
of the /etc/inittab file ignore this object. If you are operating
in a diskless environment, specifying the wait action causes
your system to boot more quickly.
|
| Command |
A 1024-character field specifying the shell command. |
| Identifier |
A 14-character parameter that uniquely identifies an object.
The Identifier must be unique. If the Identifier is
not unique, the command is unsuccessful. The Identifier cannot
be changed; if you try to change it, the command is unsuccessful. |
| RunLevel |
A 20-character parameter defining the run levels in which
the Identifier can be processed. Each process started by the init command can be assigned one or more run levels in which
it can be started. |
Security
Attention RBAC users and Trusted AIX® users: This command can
perform privileged operations. Only privileged users can run privileged
operations. For more information about authorizations and privileges,
see Privileged Command Database in Security. For a list of
privileges and the authorizations associated with this command, see
the lssecattr command or the getcmdattr subcommand.
Examples
To change
the run level of a record for tty2, enter:
chitab "tty002:23:respawn:/usr/sbin/getty /dev/tty"
The quotes are required when the record
being added has spaces or tabs.
Files
| Item |
Description |
| /etc/inittab |
Indicates which processes the init command starts. |