A short note on init script exit codes

service <your service> status

If the status action is requested, the init script will return the following exit status codes.

• 0 program is running or service is OK
• 1 program is dead and /var/run pid file exists
• 2 program is dead and /var/lock lock file exists
• 3 program is not running
• 4 program or service status is unknown
• 5-99 reserved for future LSB use
• 100-149 reserved for distribution use
• 150-199 reserved for application use
• 200-254 reserved

service <your service> start 
#or
service <your service> stop

In case of an error, while processing any init-script action except for status, the init script shall print an error message and exit with a non-zero status code:

• 1 generic or unspecified error (current practice)
• 2 invalid or excess argument(s)
• 3 unimplemented feature (for example, “reload”)
• 4 user had insufficient privilege
• 5 program is not installed
• 6 program is not configured
• 7 program is not running
• 8-99 reserved for future LSB use
• 100-149 reserved for distribution use
• 150-199 reserved for application use
• 200-254 reserved

References -

linuxbase.org