In This Article
1. File & Directory Management
ls– list filesls ls -l # detailed ls -a # include hiddencd– change directorycd /path/to/folder cd .. # up cd ~ # homecp– copy filescp file1.txt file2.txt cp -r folder1/ folder2/ # copy folder recursivelymv– move/rename filesmv file1.txt /tmp/ mv oldname.txt newname.txtrm– remove files/foldersrm file.txt rm -r folder/ # remove folder recursively rm -f file.txt # force deletemkdir– make directorymkdir new_folder mkdir -p path/to/folder # create parent foldersrmdir– remove empty directoryrmdir old_foldertouch– create empty file or update timestamptouch file.txtcat– view file contentcat file.txttree– display directory treetree tree -a # include hidden files
2. Disk & File System
df– disk space usagedf -h # human readabledu– folder/file sizedu -sh folder/ du -sh * # size of all itemsmount/umount– mount/unmount drivesmount /dev/sdb1 /mnt/usb umount /mnt/usbchmod– change permissionschmod 755 script.sh chmod +x script.sh # make executablechown– change ownerchown user:group file.txtln– create symbolic/hard linksln -s target link_name # symbolic link ln file1 file2 # hard link
3. System Info & Management
uname– system infouname -awhoami– current userwhoamiuptime– system uptimeuptimetop/htop– processestop htopps– process snapshotps aux ps -ef | grep pythonkill/killall– stop processeskill 1234 killall firefoxdf/du– disk usage infodf -h du -sh folder/date/timedatectl– check/set date and timedate sudo timedatectl set-time "2025-09-21 12:00:00"shutdown/reboot– power commandssudo shutdown -h now sudo reboot
4. Networking
ping– check connectivityping google.com ping -c 4 google.com # send 4 packetsifconfig/ip addr– network interfacesifconfig ip addrnetstat/ss– network connectionsnetstat -tuln ss -tulntraceroute– route packetstraceroute google.comnslookup/dig– DNS querynslookup google.com dig google.com
5. File Searching
find– search files/foldersfind /path -name "*.txt" find . -type d -name "backup"grep– search text inside filesgrep "hello" file.txt grep -r "error" /var/log grep -i "warning" file.txtlocate– fast file search (uses database)locate file.txt
6. Archive & Compression
tar– archive and extracttar -cvf archive.tar folder/ tar -xvf archive.tar tar -czvf archive.tar.gz folder/ tar -xzvf archive.tar.gzzip/unzip– compress/uncompresszip archive.zip file1 file2 unzip archive.zipgzip/gunzip– compress single filegzip file.txt gunzip file.txt.gz
7. Package Management (example: Debian/Ubuntu)
apt– install, update, removesudo apt update sudo apt install package_name sudo apt remove package_name sudo apt upgradedpkg– 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"
