ls | List all files and directories |
ls -l | List all files and directories with some extra information |
dir | Display directories |
mkdir <name> | Create a directory |
mkidr -p <dir_name1>/<dir_name2> | Create multiple directories |
rmdir <dir_name> | Remove an empty directory |
rm <file_name> | Remove a file/directory with confirmation |
rm -rf <file/dir_name> | Remove file/directory without confirmation |
cat <file_name> | View a file |
cat > <file_name> | Create a new file and edit it |
touch <file_name> | Create a file |
vi <file_name> | File editor |
vim <file_name> | File editor |
command >file_name | Write output of the command into the file |
cd | Change directory |
cd .. | Move one directory back |
cd - | Move to previous directory |
cd ~ | Move to current user’s home directory |
cd /home/me | Move to /home/me directory |
shutdown -h now | Shuts the system down to halt immediately. |
shutdown -r now | Shuts the system down immediately and the system reboots. |
mv -i myfile yourfile | Move the file from “myfile” to “yourfile”. This effectively changes the name of “myfile” to “yourfile”. |
mv -i /data/myfile . | Move the file from “myfile” from the directory “/data” to the current working directory. |
echo <text> | Display the text |
find | Search for files in a directory hierarchy |
grep | Search |
wc | Word count |
kill | To kill a process |
reboot | Reboot the system |
poweroff | poweroff the system |
mount | mount a partition |
umount | unmount a partition |
fdisk -l | Partition manipulator |
pwd | Prints present working directory |
hostname | Prints hostname |
whoami | Prints your login name |
date | Prints system date |
cal <year> | Prints calendar of the year |
who | Determine the users logged on the machine |
w | Determine who is logged on the system |
rwho -a | Determine the remote users |
finger <user_name> | System info about user |
last | Show list of users last logged-in on your system |
lastb | Show last unsuccessful login attempts on your system |
history | Show the used commands |
comman | Run the most recent command from the bash history commands that start with the string “ comman “ |
uptime | Display the system uptime |
ps | Process status |
ps -aux | more | List all the currently running process |
top | List the currently running process, sorted by CPU usage |
gtop, ktop, htop | GUI choice for top |
uname | Information of your system |
arch | Display the system architecture |
Xorg -version | Show the version of X windows I have on my system |
cat /etc/issue | Check what distribution you are using |
free -m | Check your usage, free memory of primary memory |
df -h | Disk free information in human readable form |
du / -bh | more | Print detailed disk usage for each sub-directory starting at the “/” (root) directory |
cat /proc/cpuinfo | Displays cpu information |
cat /etc/interrupts | List the interrupts in use |
cat /proc/version | Linux version and other info |
cat /proc/filesystems | Show the type of filesystem currently in use |
cat /etc/printcap | less | Show the setup of printers |
lsmod | Show the currently loaded kernel modules |
set | more | Show the current user environment |
env | more | Show environment variables |
dmesg | less | Print kernel messages |
chage -l <user_login_name> | See my password expiry information |
quota | Display my disk quota |
sysctl -a | more | Display all the configurable Linux kernel parameters |
runlevel | Print the previous and current runlevel |
iptables –L | Lists the current filter rules |
iptables –F | Flush the rules temporarily / Disable the rules temporarily |
iptables –h | Prints help information |
man <command_name> | Display man pages of the command |
<command_name> –help | Command help |
info <command_name> | Helping command |
whatis <command_name> | Display man pages description |
tar –cvf <file_name.tar> <file_name_1> <file_name_2> . . . | Compress files |
tar –xvf <file_name.tar> | Decompress the compressed file |
tar –xvf <file_name.tar> – C <location> | Decompress files to desired location |
tar –zcvf <file_name.tar.gz> <file_name_1> <file_name_2> | Compress files with gz |
tar –zxvf <file_name.tar.gz> | Decompress the compressed gz files |
tar –zxvf <file_name.tar.gz> -C <location> | Decompress files to desired location |
apt-get install <package_name> | Installing package(s) |
apt-get remove <package_name> | Removing package(s) |
apt-get update | Update the repository |
apt-cdrom add | Add CD ROM archives to repository |
apt-cdrom ident | Identify CD-ROM disk |
apt-get -d install <package_name> | Download packages, no installation or unpacking |
apt-get –purge remove <package_name> | Remove all traces of a package, incl. Configuration files etc., |
apt-get –u update | Upgrades all installed packages, but does not remove any packages to resolve dependencies |
apt-get –u dist-upgrade | Upgrades all the installed packages, removes or installs packages as needed to satisfy all dependencies |
apt-cache search <package_name> | Search package in the cache |
apt-get check | Check broken dependencies |
apt-cache autoclean | Remove cached packages that are no longer needed |
apt-cache clean | Remove all cached packages |
apt-get help | Help |
dpkg –l | List all the installed packages |
dpkg –L <package_name> | List files belonging to a package |
dpkg –S <file_name> | To See which package a file belongs to |
dpkg –s <package_name> | To show complete package information |
dpkg –yet-to-unpack | To look for downloaded, uninstalled packages |
dpkg –audit | Show partially installed packages |
dpkg -i <package> | Install a new package |
dpkg -r <package> | Remove a package |
yum list [available|installed|extras|updates|obsoletes|all|recent] [pkgspec] | |
yum list | List packages enabled in the repository |
yum list all | List packages enabled in the repository |
yum list available | Lists all the packages available to be installed in any enabled repository on your system |
yum list installed | Lists all the packages installed on the system |
yum list extras | Lists any installed package which no longer appears in any of your enabled repositories |
yum list obsoletes | Lists any obsoleting relationships between any available package and any installed package |
yum list updates | Lists any package in an enabled repository which is an update for any installed package |
yum list recent | Lists any package added to any enabled repository in the last seven(7) days |
yum list pkgspec | Refine your listing for particular packages |
yum check-update | It returns an exit code of 100 if there are any updates available |
yum info | Displays information about any package installed or available |
yum search | Search and list the packages |
yum provides/yum whatprovides | Searches for which packages provide the requested dependency of file and also takes wildcards for files |
yum clean | Clean up the cache of metadata and packages |
yum clean packages | Cleans up any cached packages in any enabled repository cache directory |
yum clean metadata | Cleans up any xml metadata that may have been cached from any enabled repository |
yum clean dbcache | Clean up the cached copies of those from any enabled repository cache |
yum clean all | Clean all cached files from any enabled repository |
yum shell / yum makecache | These two commands are used to download and make usable all the metadata for the currently enabled yum repos |
rpm –ivh <package_name> | Install a new package |
rpm –Uvh <package_name> | Update an already installed package |
rpm –e<package_name> | Remove a package |
rpm –aq | To list all rpm packages installed on your system |
rpm –F <package_name> | Freshening up the already installed package |
rpm –version | Prints rpm version |
/bin | User Binaries |
/sbin | System Binaries |
/etc | Configuration Files |
/root | Root User’s Home Directory |
/dev | Device Files |
/proc | Precess Information |
/media | Removable Media |
/var | Variable Files |
/tmp | Temporary Files |
/usr | User Programs |
/home | Home Directories |
/boot | Bootloader Files |
/lib | System Libraries |
/opt | Optional add-on Apps |
/mnt | Mount Directory |
/srv | Service Data |
ifconfig | Displays all the interface information |
ifstat | Check the current network usage |
iptraf | A network utility allows you check the network activities |
ifup | Bring a network interface up |
ifdown | Bring a network interface down |