1. File and Directory Management Commands
ls
- Usage: Lists files and directories.
- Syntax: ls [options] [path]
- Example:ls: List files in the current directory.ls -l: List files in long format with details like permissions, owner, size, etc.ls -a: List all files, including hidden files.
cd
- Usage: Changes the current directory.
- Syntax: cd [directory]
- Example:cd /home/user: Change to the specified directory.cd ..: Move to the parent directory.cd ~: Move to the home directory.
pwd
- Usage: Prints the current working directory.
- Syntax: pwd
- Example: pwd
mkdir
- Usage: Creates a new directory.
- Syntax: mkdir [options] directory_name
- Example:mkdir my_folder: Creates a directory named my_folder.mkdir -p dir1/dir2: Creates nested directories.
rm
- Usage: Removes files or directories.
- Syntax: rm [options] file_or_directory
- Example:rm file.txt: Deletes file.txt.rm -r folder: Deletes a directory and its contents recursively.
rmdir
- Usage: Removes an empty directory.
- Syntax: rmdir directory_name
- Example: rmdir empty_folder
cp
- Usage: Copies files or directories.
- Syntax: cp [options] source destination
- Example:cp file1.txt file2.txt: Copies file1.txt to file2.txt.cp -r folder1 folder2: Copies folder1 to folder2 recursively.
mv
- Usage: Moves or renames files or directories.
- Syntax: mv [options] source destination
- Example:mv file1.txt file2.txt: Renames or moves file1.txt to file2.txt.
2. File Viewing Commands
cat
- Usage: Displays the content of a file.
- Syntax: cat [options] file
- Example:cat file.txt: Displays the content of file.txt.cat file1.txt file2.txt > merged.txt: Concatenates two files into a new file.
more
- Usage: Displays file content page by page.
- Syntax: more [file]
- Example: more file.txt
less
- Usage: Displays file content, allowing navigation.
- Syntax: less [file]
- Example: less file.txt
head
- Usage: Displays the first few lines of a file.
- Syntax: head [options] file
- Example: head -n 10 file.txt (Shows the first 10 lines).
tail
- Usage: Displays the last few lines of a file.
- Syntax: tail [options] file
- Example: tail -n 10 file.txt (Shows the last 10 lines).
3. File Permission and Ownership Commands
chmod
- Usage: Changes file permissions.
- Syntax: chmod [options] mode file
- Example:chmod 755 file.txt: Sets read, write, and execute for owner; read and execute for group and others.
chown
- Usage: Changes file ownership.
- Syntax: chown [owner][:group] file
- Example: chown user:group file.txt
chgrp
- Usage: Changes group ownership.
- Syntax: chgrp [group] file
- Example: chgrp group file.txt
4. Process Management Commands
ps
- Usage: Displays information about active processes.
- Syntax: ps [options]
- Example:ps: Displays processes for the current shell.ps -ef: Displays all running processes.
top
- Usage: Shows real-time processes and system resource usage.
- Syntax: top
kill
- Usage: Terminates a process by PID.
- Syntax: kill [signal] PID
- Example: kill -9 12345
jobs
- Usage: Lists background jobs.
- Syntax: jobs
fg
- Usage: Brings a background job to the foreground.
- Syntax: fg [job_id]
bg
- Usage: Resumes a suspended job in the background.
- Syntax: bg [job_id]
5. Networking Commands
ping
- Usage: Checks connectivity to a host.
- Syntax: ping [options] host
- Example: ping google.com
netstat
- Usage: Displays network connections and statistics.
- Syntax: netstat [options]
curl
- Usage: Transfers data from or to a server.
- Syntax: curl [options] URL
- Example: curl https://example.com
wget
- Usage: Downloads files from the web.
- Syntax: wget [options] URL
- Example: wget https://example.com/file.txt
scp
- Usage: Copies files between hosts.
- Syntax: scp [options] source destination
- Example: scp file.txt user@host:/path/to/destination
ssh
- Usage: Logs into a remote machine securely.
- Syntax: ssh user@host
- Example: ssh [email protected]
6. Disk Usage Commands
df
- Usage: Displays disk space usage.
- Syntax: df [options]
- Example: df -h (Shows human-readable format).
du
- Usage: Displays directory or file space usage.
- Syntax: du [options] [path]
- Example: du -sh folder/
7. Search and Filter Commands
grep
- Usage: Searches for a pattern in files.
- Syntax: grep [options] pattern file
- Example:grep 'hello' file.txt: Searches for ‘hello’ in file.txt.grep -r 'error' /var/logs: Searches recursively for ‘error’ in /var/logs.
find
- Usage: Searches for files and directories.
- Syntax: find [path] [options]
- Example:find . -name "*.txt": Finds all .txt files in the current directory.find /home -size +100M: Finds files larger than 100MB.
awk
- Usage: Processes and analyzes text.
- Syntax: awk 'pattern {action}' file
- Example: awk '{print $1}' file.txt: Prints the first column of a file.
sed
- Usage: Edits text in a file or stream.
- Syntax: sed 'script' file
- Example: sed 's/old/new/g' file.txt: Replaces ‘old’ with ‘new’.
8. Archiving and Compression Commands
tar
- Usage: Archives files and directories.
- Syntax: tar [options] archive_name file_or_directory
- Example: tar -cvf archive.tar folder
gzip
- Usage: Compresses files.
- Syntax: gzip [file]
- Example: gzip file.txt
unzip
- Usage: Extracts ZIP files.
- Syntax: unzip file.zip
This list provides an essential toolkit for working effectively in a Unix environment. Mastering these commands can significantly enhance your productivity and proficiency!
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