init.d - initialization and termination scripts

/etc/init.d is a directory containing initialization and termination scripts for changing init states. These scripts are linked when appropriate to files in the rc?.d directories, where `?' is a single character corresponding to the init state.

File names in rc?.d directories are of the form [SK]nn<init.d filename>, where S means start this job, K means kill this job, and nn is the relative sequence number for killing or starting the job. When entering a state (init S,0,2,3,etc.) the rc[S0-6] script executes those scripts in /etc/rc[S0-6].d that are prefixed with K followed by those scripts prefixed with S. When executing each script in one of the /etc/rc[S0-6] directories, the /sbin/rc[S0-6] script passes a single argument. It passes the argument 'stop' for scripts prefixed with K and the argument 'start' for scripts prefixed with S. There is no harm in applying the same sequence number to multiple scripts. In this case the order of execution is deterministic but unspecified.

/etc/services - A mapping between friendly textual names for internet services, and their underlying assigned port numbers and protocol types. inetd.conf - The service is currently running on the machine.

Service Scripts: /etc/rc.d/init.d