Class Notes

History

• Type history to view past commands
  • !#### will copy and execute commands
• Ctrl+R does most recent command

• chmod changes permission
  • e.g. "chmod 644 genetic-code.sed"

• Hitting tab twice will auto show all options to select from

Other Commands

• grep "ACTG" will look for typed letters ACTG in a string of text
  • if typed letters are present in a file, letters will appear red
    • grep "letters" file_name will search for letters in a file and open it
  • "." is a wildcard

"^" is the caret line, which only searches at the beginning of the line

• • "$" searches only at the end of the line

• "wc" shows word count
  • Hit Ctrl D to finish typing text after wc command
    • first number tells # of lines
    • second number tells # of words
    • third number tells # of characters
  • combine commands with this notation: command | command
    • • you can string multiple commands together in one string