Essential Command Line One-Liners for Developers

Mastering the command line is crucial for efficient development. Here are some powerful one-liners that can significantly boost your productivity by simplifying common tasks. These commands are designed for Unix-like systems (Linux, macOS) and can be used in your terminal or shell scripts.

File and Directory Management

• Print files and directories in a tree structure:

  find . | sed -e "s/[^-][^\/]*\// |/g" -e "s/|\([^ ]\)/|-\1/"

• Print only directories in a tree structure:

  find . -type d | sed -e "s/[^-][^\/]*\// |/g" -e "s/|\([^ ]\)/| - \1/"

• Recursively remove directories that contain no files:

  find . -depth -type d -exec rmdir {} \;

• Display all files/directories sorted by size (human-readable):

  du -ah . 2>/dev/null | sort -hr | less

• Make multiple copies of a file:

  tee filecopy{1..10}.txt < file.txt

Data and Text Manipulation

• Find common lines present in two files:

  cat file1 file2 | uniq -d

• Find lines in file1 that are not present in file2:

  comm -23 file1 file2

• Find the most frequently used commands in history:

  history | cut -c8- | sort | uniq -c | sort -rn | head

System and Network Information

• Quick access to the ASCII table:

  man ascii

• Count the number of total active network interfaces (excluding loopback):

  wc -w <<<$(netstat -i | cut -d" " -f1 | egrep -v "^Kernel|Iface|lo")

These one-liners are invaluable for quick tasks and can be combined to create more complex operations. Experiment with them to see how they can streamline your daily command-line usage.

Further Learning Resources

• MDN Date Documentation - Understand date and time handling in JavaScript.
• Bash Reference Manual - Deep dive into the Bash shell.
• Stack Overflow - Bash Tag - Find solutions and discussions on Bash scripting.