Lecture 2a - Common Unix Commands and Their Usage

Structure of a Unix Command

Useful Unix Commands

What do they do? How and why do we use these commands?
Below is a small list of commands we will go over in class. SOME of the flags useful with them are listed as well.

• ls : list contents of a directory
  • usage: ls directoryPathname -- lists items in specified directory.
  • Flags: -l -a (there's more too!)
• cat : view file contents
  • usage: cat filenameToView
• more : view file contents, but pause each screen. Page through each screen with space bar.
  • usage: more filenameToView
• less : view file contents, pause each screen, space bar, use of arrow keys.
  • usage: less filenameToView
• touch : creates file or updates file timestamp
  • usage: touch SomeFilename
• cp : copy file to another file or location
  • usage: cp WhatToCopy WhereToCopyTo
  • Flags: -i -r
• mv : move file to another file or location (move file to another file, whaaaaaa?)
  • usage: mv WhatToMove WhereToMoveTo
• rm : remove file (or directory... hm...)
  • usage: rm FileToDelete
• Flags: -r Recursively Removes. Use this when removing a directory and everything in that directory.
• pwd : displays absolute pathname to current directory
  • usage: pwd
• mkdir : create directory
  • usage: mkdir NewDirectoryName
• rmdir : remove directory (EMPTY ONES ONLY!)
  • usage: rmdir DirectoryToRemove
• cd : (change directory) navigate through directories
  • usage: cd WhereToMoveTo
• wc : word count
  • usage: wc FileToTakeWordCountOf
  • flags: -w -c -l
• passwd : use this command to change your account password
• man : use the man command with any other command name as a parameter to open up a manual page to see useage notes and flags available with any unix command. (you can also list any command name with --help afterwards to see a smaller help page).

(c) Melina Vastola, 2015