Essential and Lesser-Known Linux/Unix Tools Every Developer Should Know
In the world of Linux/Unix, there are a variety of well-known tools and commands, ranging from those that are commonly used to more niche and obscure utilities that can be extremely powerful for advanced users. Here’s a brief overview of the most widely used and the lesser-known but intriguing tools, explained from the perspective of a developer. Widely Known Tools and Their Uses
1. ls
Purpose: Lists directory contents.
Example Usage:
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ls -alh
This command lists all files (including hidden files) with human-readable file sizes in a long listing format.
2. grep
Purpose: Searches for patterns in files.
Example Usage:
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grep -r "pattern" /path/to/directory
Recursively searches for “pattern” in all files within the specified directory.
3. awk
Purpose: A programming language for text processing.
Example Usage:
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awk '{print $1}' file.txt
Prints the first column from the file.
4. sed
Purpose: Stream editor for modifying files.
Example Usage:
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sed 's/old/new/g' file.txt
Replaces all instances of “old” with “new” in the file.
5. find
Purpose: Searches for files and directories.
Example Usage:
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find /path -name "*.txt"
Finds all .txt files under the specified directory.
6. tar
Purpose: Archives files.
Example Usage:
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tar -czvf archive.tar.gz /path/to/files
Creates a compressed tarball of the specified files.
7. curl
Purpose: Transfers data from or to a server using various protocols.
Example Usage:
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curl -O https://example.com/file.zip
Downloads a file from a URL.
8. ps
Purpose: Displays information about running processes.
Example Usage:
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ps aux | grep my_process
Finds all processes matching “my_process.”
9. chmod
Purpose: Changes file permissions.
Example Usage:
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chmod +x script.sh
Adds execute permissions to a script.
10. top
Purpose: Displays system resource usage, including CPU and memory.
Example Usage:
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top
Opens a real-time view of system resource usage.
Lesser-Known Yet Powerful Tools
1. strace
Purpose: Traces system calls made by a program.
Example Usage:
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strace -p <pid>
Attaches to a process by PID and logs its system calls. This is particularly useful for debugging or investigating process behavior.
2. htop
Purpose: An interactive process viewer.
Example Usage:
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htop
A more user-friendly alternative to top with an interactive interface, including CPU and memory usage visualization.
3. ncdu
Purpose: Disk usage analyzer with an ncurses interface.
Example Usage:
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ncdu /path/to/dir
Analyzes disk usage and provides a navigable, interactive interface to view disk space consumption.
4. tldr
Purpose: Simplified man pages.
Example Usage:
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tldr
ls Provides a concise, example-based summary of the ls command (useful for quick reference).
5. lsof
Purpose: Lists open files and the processes using them.
Example Usage:
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lsof -i :8080
Lists processes using the network port 8080.
6. jq
Purpose: Command-line JSON processor.
Example Usage:
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cat file.json | jq '.key'
Extracts the value of .key from the JSON file.
7. inotifywait
Purpose: Waits for file system events.
Example Usage:
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inotifywait -m /path/to/dir
Monitors changes in a directory and outputs events such as file modifications or deletions.
8. asciinema
Purpose: Records and shares terminal sessions.
Example Usage:
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asciinema rec
Starts recording a terminal session, which can be shared later online.
9. zsh
Purpose: A powerful shell with advanced features.
Example Usage:
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zsh
Launches the zsh shell, which offers superior auto-completion, globbing, and scripting features compared to bash.
10. fd
Purpose: A fast alternative to find.
Example Usage:
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fd "*.txt"
A faster, simpler alternative to find that supports fuzzy searching and other advanced features. The Art of Combining Tools
The power of the Unix philosophy lies in the ability to combine small, simple tools to achieve complex results. For example:
Searching and modifying files:
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grep -rl "pattern" /path/to/dir | xargs sed -i 's/old/new/g'
Network monitoring:
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netstat -tuln | grep ":80"
Disk usage analysis:
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du -sh * | sort -rh | head -n 10
Conclusion
Whether you are a novice or an experienced developer, these tools form the backbone of system administration, programming, and debugging in Linux/Unix. While the commonly known tools like grep, ls, and ps are essential, the lesser-known utilities like strace, jq, and inotifywait can offer tremendous value in complex scenarios. Knowing when and how to combine them allows you to accomplish tasks more efficiently and gain deeper insight into system behavior.