etcrcdinitd

etcrcdinitd is typically a reference to the /etc/rc.d/init.d directory, the locus of SysV-style init scripts on many Linux distributions. This directory contains executable shell scripts that control daemons and services: each script can be invoked with arguments such as start, stop, restart, and status to perform corresponding actions. Scripts in this location are expected to be able to initialize a service and manage it across boot, shutdown, and runtime.

In traditional SysV init systems, service startup is coordinated by runlevels. The system uses runlevel-specific directories such as /etc/rc.d/rc0.d through /etc/rc.d/rc6.d, which contain symlinks to the scripts in /etc/rc.d/init.d. Files beginning with S (for start) order the services to be started, while those beginning with K (for kill) stop them. The numeric prefix controls startup ordering.

Management utilities include chkconfig (Red Hat family) and update-rc.d (Debian family), which create or remove the symbolic links in the runlevel directories and can query a script for its default start/stop levels. The service command is a front end that dispatches to the script.

Many modern distributions have moved to systemd, which uses unit files and systemctl for service management. The /etc/rc.d/init.d scripts may be kept for backward compatibility, or run as compatibility shims invoking systemd, or may be unused in favor of native units. Creating a new init script typically involves implementing start and stop behavior, optionally adding a LSB header to specify dependencies and runlevel defaults.