Linux 5 guiding process 2 [analyzing inittab]

Inittab file profiling #1 grep-V "^ #"/etc/inittab | more #2 man inittab ID #3 in inittab, all entries are in the following format: ID: run-levels: Action: process ID: identifier, generally two letters or numbers run-levels: Specifies the running level. You can specify multiple [left-hand boarding bricks, kicking] actions: specify the running status [Where to beat him] process: Specify the script/command to run. [Li Ming beat Master. Others care about this process first. Where to beat the action, and then how to use the Run-levels? [Instructor Gao reported that I was arrested, and each criminal file would have a number-often time and file ID, no one cares about this.] [focus on learning] ----- general process ---- firmware initdefault | bootloader/etc/rc. d/RC. sysinit | kernel/etc/rc. d/RC |/etc/inittab/etc/rc. d/rcN. d N 0 ~ 6 | Username Password --------------------------------------------------------- #4 ID: 5: initdefault: ID: Run-levels: Action: Process #5 how to guide/etc/rc. d/RC. the sysinit script runs every time the system starts it! Start the script of the System Service-> the Service Startup Program 0 1 2 3 4 5 6/etc/rc in the service startup directory. d/rc0.d rc1.d rc2.d ...... s-start k-kill k85mdmpd in theory, the smaller the first start .. Or kill the digital Script Name HP @ Ubuntu:/etc/rc3.d $ ls readme s50pulseaudio S70dns-clean S99acpi-support s99rc. local s20kerneloops s50rsync S70pppd-dns S99grub-common S20speech-dispatcher s50saned s75sudo S99laptop-modeaction common values: initdefault: Specify the run level of the system default start sysinit: system start execute the command specified in the process wait: Execute the command specified in the process, run other commands after the execution of the command once: Execute the specified command in process, do not wait for it to end ctrlaltdel: Press CTRL + ALT + DEL when the execution of the process specified command terminal 6, you can also add a terminal by yourself, CTRL + ALT + F7 restores the terminal and exits. It does not mean termination! Start the script/etc/rc. d/RC. sysinit completes System Service Program startup, such as setting system environment variables, setting system clock, loading fonts, checking and loading file systems, and generating system startup information log files. Determine the default running level and call/etc/rc. d/RC Script, execute the service programs in the corresponding running level directory, and complete the initialization settings for the corresponding running level/etc/rc. d/init. d. The directory contains the service program scripts/etc/rc at various running levels. d/RC [0123456]. d. Store the symbolic links corresponding to the running-level service program scripts and link them to init. the corresponding script in the d directory sets the self-starting program ln-s chkconfig ntsysv related commands and logs run dmesg check errors during boot dmesg | grep eth0 checks whether the hardware is identified by the kernel to check system logs/ var/log/messages, find application errors that may be ignored by dmesg