• In Ubuntu, you can run ifconfig from any user but not in Debian
# Examples /sbin/ifconfig
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File System Layout
• Important directories for sysadmin ◇ /etc ▪ pronouced as “et - c” ▪ contains configuartion data for applications - /etc/apt - /etc/crontab - /etc/ssh ◇ /sbin ▪ contains secured binaries, critical files ◇ /bin ▪ contains binaries of the base OS or links to binaries
• Others ◇ /dev ▪ contains all your devices ◇ /home ▪ home for all users that is not root ◇ /root ▪ /home directory for root ◇ /lib ◇ /lib64 ▪ system libraries (like dll in windows) ◇ /media ▪ automatic mount ◇ /mnt ▪ manual mount ◇ /opt ▪ commercial programs e.g. dropbox ▪ packages not installed via package manager ▪ compiled programs - make a link from /bin to /opt ◇ /proc ▪ kernel files (virutal fs) ▪ one directory for each process running on the machine ◇ /tmp ▪ clear when you reboot the machine ◇ /usr ▪ /usr/local - compiled programs ▪ /usr/sbin - system admin commands ▪ /usr/share - configuration files, themes, icons, wallpapers, sound files → /usr/share/doc ⇒ documentation files → /usr/share/applications ⇒ .desktop files ◇ /var ▪ various files - files that change all the time ▪ /var/log - log files ◇ /lost+found ▪ found in ext4 file system
# Reference # Descriptions of filesystem hierarchy man hier
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File Types
• As shown in permission bits from ls command ◇ ordinary (-) ◇ links (l) ◇ directory (d) ◇ block device (b) ◇ character device (c) ◇ named pipes ◇ local sockets
ls -l /dev |grep sd # show block device files ls -l /dev/input/mouse0 # show character device file
Index