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rcs(5) [linux man page]

rcS(5)							   Debian Administrator's Manual						    rcS(5)

rcS - variables that affect the behavior of boot scripts DESCRIPTION
The /etc/default/rcS file contains variable settings in POSIX format: VAR=VAL Only one assignment is allowed per line. Comments (starting with '#') are also allowed. OPTIONS
The following variables can be set. For the default values please see /usr/share/initscripts/default.rcS. TMPTIME On boot the files in /tmp will be deleted if their modification time is more than TMPTIME days ago. A value of 0 means that files are removed regardless of age. If you don't want the system to clean /tmp then set TMPTIME to a negative value (e.g., -1) or to the word infinite. SULOGIN Setting this to yes causes init to spawn a sulogin on the console early in the boot process. If the administrator does not login then the sulogin session will time out after 30 seconds and the boot process will continue. DELAYLOGIN Normally the system will not let non-root users log in until the boot process is complete and the system has finished switching to the default runlevel (usually level 2). However, in theory it is safe to log in a bit earlier, namely, as soon as inetd has started. Setting the variable to no allows earlier login; setting the variable to yes prevents it. Some details: The DELAYLOGIN variable controls whether or not the file /var/lib/initscripts/nologin is created during the boot process and deleted at the end of it. /etc/nologin is normally a symbolic link to the latter location, and the login(1) program refuses to allow non-root logins so long as (the target of) /etc/nologin exists. If you set the variable to no then it is advisable to ensure that /var/lib/initscripts/nologin does not exist. UTC This is used to govern how the hardware real time clock is interpreted when it is read (e.g., at boot time, for the purpose of set- ting the system clock) and when it is written (e.g., at shutdown). If this option is set to no then the system clock is assumed to be set to local time. If the option is set to yes then the system clock is assumed to be set to something approximating Coordinated Universal Time (UTC). (POSIX systems keep a variant of UTC, without leap seconds.) On contemporary Debian systems (although change has been requested at, if UTC is set to no then /usr/share/zoneinfo must be readable early in the boot process. If you want to keep /usr on a separate filesystem then you must still ensure that the target of /etc/localtime points to the correct zone information file for the time zone of the time kept in your hardware real time clock. VERBOSE Setting this option to no (in lower case) will make the boot process a bit less verbose. Setting this option to yes will make the boot process a bit more verbose. FSCKFIX When the root and all other file systems are checked, fsck is invoked with the -a option which means "autorepair". If there are major inconsistencies then the fsck process will bail out. The system will print a message asking the administrator to repair the file system manually and will present a root shell prompt (actually a sulogin prompt) on the console. Setting this option to yes causes the fsck commands to be run with the -y option instead of the -a option. This will tell fsck always to repair the file sys- tems without asking for permission. NOTE
The EDITMOTD and RAMRUN variables are no longer used. AUTHOR
Miquel van Smoorenburg <> SEE ALSO
inetd(8), init(8), inittab(5), login(1). 16 Jan 2006 rcS(5)

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SULOGIN(8)						Linux System Administrator's Manual						SULOGIN(8)

sulogin - Single-user login SYNOPSIS
sulogin [ -e ] [ -p ] [ -t SECONDS ] [ TTY ] DESCRIPTION
sulogin is invoked by init(8) when the system goes into single user mode. (This is done through an entry in inittab(5).) Init also tries to execute sulogin when the boot loader (e.g., grub(8)) passes it the -b option. The user is prompted Give root password for system maintenance (or type Control-D for normal startup): If the root account is locked, no password prompt is displayed and sulogin behaves as if the correct password were entered. sulogin will be connected to the current terminal, or to the optional device that can be specified on the command line (typically /dev/con- sole). If the -t option is used then the program only waits the given number of seconds for user input. If the -p option is used then the single-user shell is invoked with a dash as the first character in argv[0]. This causes the shell process to behave as a login shell. The default is not to do this, so that the shell will not read /etc/profile or $HOME/.profile at startup. After the user exits the single-user shell, or presses control-D at the prompt, the system will (continue to) boot to the default runlevel. ENVIRONMENT VARIABLES
sulogin looks for the environment variable SUSHELL or sushell to determine what shell to start. If the environment variable is not set, it will try to execute root's shell from /etc/passwd. If that fails it will fall back to /bin/sh. This is very valuable together with the -b option to init. To boot the system into single user mode, with the root file system mounted read/write, using a special "fail safe" shell that is statically linked (this example is valid for the LILO bootprompt) boot: linux -b rw sushell=/sbin/sash FALLBACK METHODS
sulogin checks the root password using the standard method (getpwnam) first. Then, if the -e option was specified, sulogin examines these files directly to find the root password: /etc/passwd, /etc/shadow (if present) If they are damaged or nonexistent, sulogin will start a root shell without asking for a password. Only use the -e option if you are sure the console is physically protected against unauthorized access. AUTHOR
Miquel van Smoorenburg <> SEE ALSO
init(8), inittab(5). 17 Jan 2006 SULOGIN(8)

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