Essential Linux Commands and File Management Techniques

rmdir

Remove a directory (only works for empty directories)

cp

Copy files or directories

pwd

Print current working directory

ls

List directory contents

ls -l

List with detailed info (permissions, size, etc.)

ls -a

List hidden files

cd

Change directory

cd ..

Move up one directory

cd ~

Move to home directory

mkdir

Create a new directory

rm -r

Remove a directory and its contents

cp -r

Copy directories recursively

mv

Move or rename files

rm

Remove files

rm -f

Force remove (use with caution)

touch

Create an empty file

chmod

Change file permissions

chown

Change file ownership

ls -l (permissions)

Shows file permissions in the listing (drwxr-xr-x)

cat

View contents of a file

less

View file contents page by page

head

View the first few lines of a file

tail

View the last few lines of a file

tail -f

Continuously view new lines in a file (useful for logs)

nano

Simple text editor

vim

More advanced text editor

find

Search for files

grep

Search inside files for text patterns

top

Real-time system monitor for processes

ps

View current processes

ps aux

Detailed process list

df

Disk space usage

du

Disk usage of directories and files

free

Memory usage

tar

Archive files

tar -cvf

Create archive

tar -xvf

Extract archive

gzip

Compress files

gzip file.txt

Compress file

gunzip

Decompress file

Numerical Notation (rwx)

7 = Read + Write + Execute, 6 = Read + Write, 5 = Read + Execute, 4 = Read

Example: chmod 755 file.sh

Owner has all permissions, group and others can read and execute