Basic Input/Output and Process Control

• Reading from a File:
  • cmd < ios.md: Reads input
  • cmd << ok: Reads until "ok" is entered on a new line.
• Writing to a File:
  • cmd > file.txt: Overwrites .
  • cmd >> file.txt: Appends
  • cmd > null: Discards all
• Piping Output:
  • cmd1 | cmd2: Directs output of cmd1 as input to cmd2.
• Showing Success/Failure:
  • cmd -v: verbose
• Variables:
  • var='hello': Creates a variable
  • echo $var: Displays
• Running in Background:
  • cmd &: Runs cmd in the background.

Wildcards for File Matching

• hello*.jsx: Matches files starting with "hello" and ending with ".jsx"
• test?.jsx: "test", followed by any single character
• {c,m,p}at: Matches "cat", "mat", or "pat".
• {1..9}: 1 to 9

System Information

• whoami: Shows your current username.
• who: Lists all users currently logged in.
• man cmd: Displays manual page (notes style) for cmd.
• su <user>: Switches to the specified user, requiring their password. If no user is specified, it defaults to the root user.
• passwd <user>: Changes the password for the specified user.