bin/: command binaries for commands, example /bin/ls is binaries for ls command
boot/: system boot loader files
dev/: Stores hardware and software device drivers. This directory maintains file system entries that represent the devices connected to the system (for example, the /dev/sda1 partition).
etc/: system-wide config
passwd: user and group info
shadow: user password reset, expire info
profile
bash
skel/
files for template, all new users have these files
login.defs
group: existing group and any users account that are a member
The syntax for /etc/sudoers entries is username hostname = (user) command
username is the user to whom privileges are being given
hostname is the terminal from which commands can be run
user is the level of access
command is the delegated executable.
ex: strix ALL=(ALL) NOPASSWD: SHUTDOWN_CMDS where SHUTDOWN_CMDS is alias for all shutdown/reboot system commands
share/
polkit-t/
rules.d with js files for local policies
polkit-1/
rules.d with js files for third-party policies
ssh/
sshd_config: configure who is allowed to remotely connect to the server, what level of remote access they will have, also instruction or warning message.
home/: user home dir, $HOME or ~
user1/
.bash_profile
lib/: Stores shared program libraries required by the kernel, command-line utilities, and binaries.
media/: media file such as CD-ROM
mnt/: temporary mount
opt/: Stores optional files of large software packages. These packages normally create a subdirectory bearing their name under the /opt directory and then place their files in the subdirectory. For example, the /opt/nessus subdirectory contains files for the Nessus vulnerability scanning program.
proc/: a [Virtual File System] that represents continually updated kernel information to the user in a typical file format (for example, the /proc/mounts file).
root/: home dir for root
run/: run-time program data
sbin/: Stores binaries that are used for completing the booting process and also the ones that are used by the root user. For example, the /sbin/ifconfig file is the binary for the ifconfig command that is used to manage network interfaces on the system
srv/: site-specific data served by this system
sys/: a Virtual File System (VFS), primarily stores information about devices. For example, /sys/block includes links to devices that are stored in various subdirectories under the /sys/ devices/ location, which presents a hierarchy of devices in the kernel.
tmp/: temporary files
usr/: unix system resources, read-only dir that stores small programs and file accessible to all users
bin/: include executable programs that can be executed by all users
local/: include custom build applications that are stored here by default
lib/: including object libraries and internal library that are needed by the executable programs
lib64/: same as lib/ but for 64 bit system
share/: Includes read-only architecture independent files. These files can be shared among different architectures of an operating system.
doc/
pokit-1/
actions/
.policy with XML files for defining actions
sbin/
var/: files that is expected to continuously change, Examples include log files, printer spools, and some networking services’ configuration files.