In This Article
1. File & Directory Management
lsβ list filesls ls -l # detailed ls -a # include hiddencdβ change directorycd /path/to/folder cd .. # up cd ~ # homecpβ copy filescp file1.txt file2.txt cp -r folder1/ folder2/ # copy folder recursivelymvβ move/rename filesmv file1.txt /tmp/ mv oldname.txt newname.txtrmβ remove files/foldersrm file.txt rm -r folder/ # remove folder recursively rm -f file.txt # force deletemkdirβ make directorymkdir new_folder mkdir -p path/to/folder # create parent foldersrmdirβ remove empty directoryrmdir old_foldertouchβ create empty file or update timestamptouch file.txtcatβ view file contentcat file.txttreeβ display directory treetree tree -a # include hidden files
2. Disk & File System
dfβ disk space usagedf -h # human readableduβ folder/file sizedu -sh folder/ du -sh * # size of all itemsmount/umountβ mount/unmount drivesmount /dev/sdb1 /mnt/usb umount /mnt/usbchmodβ change permissionschmod 755 script.sh chmod +x script.sh # make executablechownβ change ownerchown user:group file.txtlnβ create symbolic/hard linksln -s target link_name # symbolic link ln file1 file2 # hard link
3. System Info & Management
unameβ system infouname -awhoamiβ current userwhoamiuptimeβ system uptimeuptimetop/htopβ processestop htoppsβ process snapshotps aux ps -ef | grep pythonkill/killallβ stop processeskill 1234 killall firefoxdf/duβ disk usage infodf -h du -sh folder/date/timedatectlβ check/set date and timedate sudo timedatectl set-time "2025-09-21 12:00:00"shutdown/rebootβ power commandssudo shutdown -h now sudo reboot
4. Networking
pingβ check connectivityping google.com ping -c 4 google.com # send 4 packetsifconfig/ip addrβ network interfacesifconfig ip addrnetstat/ssβ network connectionsnetstat -tuln ss -tulntracerouteβ route packetstraceroute google.comnslookup/digβ DNS querynslookup google.com dig google.com
5. File Searching
findβ search files/foldersfind /path -name "*.txt" find . -type d -name "backup"grepβ search text inside filesgrep "hello" file.txt grep -r "error" /var/log grep -i "warning" file.txtlocateβ fast file search (uses database)locate file.txt
6. Archive & Compression
tarβ archive and extracttar -cvf archive.tar folder/ tar -xvf archive.tar tar -czvf archive.tar.gz folder/ tar -xzvf archive.tar.gzzip/unzipβ compress/uncompresszip archive.zip file1 file2 unzip archive.zipgzip/gunzipβ compress single filegzip file.txt gunzip file.txt.gz
7. Package Management (example: Debian/Ubuntu)
aptβ install, update, removesudo apt update sudo apt install package_name sudo apt remove package_name sudo apt upgradedpkgβ manage local packagesdpkg -i package.deb dpkg -r package_name
8. Bash Scripting Basics
- Variables
name="John" echo "Hello $name" - Conditionals
if [ -f "file.txt" ]; then echo "File exists" else echo "No file" fi - Loops
for i in 1 2 3; do echo "Number $i" done - Functions
myfunc() { echo "Hello $1" } myfunc World - Read input
read -p "Enter name: " name echo "Hello $name"