Unix Text Editors

1
Unix Text Editors

• Chapter 15 16

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Unix Text Editors

• What is a text editor?
• Three popular ones exist here on alpha
• pico
• emacs
• vi
• Going to give an overview of each
• Focus on pico, the easiest

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pico

• Created at the University of Washington
• Very popular program
• Easiest to use of all text editors

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Starting pico

• pico file name
• file name can be an existing file
• If file name does not exist, it will be created
• Pico displays most control commands
• Just type

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Pico Navigation

• Use arrow keys, otherwise
• Ctrl-f move forward a character
• Ctrl-b move backward a character
• Ctrl-n move to the next line
• Ctrl-p move to the previous line
• Ctrl-v move forward one page
• Ctrl-y move backward one page

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Pico Editing

• Inserting
• Just type
• Deleting
• Ctrl-k deletes the current line of text
• Ctrl-u uncuts the last cut text

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Exiting Pico

• To exit
• Ctrl-x
• May need to save your work

8
emacs

• Probably the most powerful
• More than just a text editor
• Could take whole classes on emacs

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Starting emacs

• emacs file name
• file name can be an existing file
• If file name does not exist, it will be created
• Just type
• No control commands are displayed

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emacs navigation

• Use the arrow keys (if they exist), otherwise
• Ctrl-f forward one character
• Ctrl-b backward one character
• Esc-f forward one word
• Esc-b backward one word
• Ctrl-n next line
• Ctrl-p previous line
• Ctrl-v next screen
• Esc-v previous screen

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emacs editing

• Inserting
• Just type
• Deleting
• delete deletes backward
• Ctrl-d deletes forward
• Esc-delete deletes back one word
• Esc-d deletes forward one word

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emacs editing

• Killing yanking
• Ctrl-k kills from the cursor to the end of the
  line
• Ctrl-y yanks the text back out of memory

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Saving Exiting emacs

• To save your work
• Ctrl-x Ctrl-\
• To exit emacs
• Ctrl-x Ctrl-c
• Will prompt you to save if necessary

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vi text editor

• Generally comes on all Unix systems
• Probably the worst interface of all
• Many hard-core Unix users love it
• There is an updated version, vim, that is quite
  popular

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vi text editor

• Invoked the same way as emacs pico
• vi file name
• file name can be an existing file.
• If file name does not exist, will be created
• The vi window
• Note the
• In command mode

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vi modes

• Command mode
• Get to command mode by pressing the esc key
• Keystrokes execute commands
• Input mode
• Get there by typing certain commands from command
  mode.
• Keystrokes type letters on the screen

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vi modes

• Last line mode
• Get there by typing a from the command mode
• Begins with a (colon) also used to issue
  commands
• No way to tell what mode you are in

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Command mode

• Navigation
• Use the arrow keys or
• l or space move forward one character
• h or backspace move back one character
• j or return move down one line
• k or - move up one line

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Input mode

• Inserting text from command mode
• i inserts text to the left of the cursor
• a inserts text to the right of the cursor
• R replaces the text as you type
• o inserts a blank line below the current line
• O inserts a blank line above the current line
• All of these commands put you into the input mode

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Command mode

• Deleting text
• x deletes one character
• dd deletes an entire line
• Number modifier for both

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Line mode

• Saving and exiting
• From command mode type a (colon)
• Places you into the line mode
• Then type the command to execute

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Line mode

• q quits the program - unless changes have been
  made
• w writes (saves) the changes
• q! quits without saving changes
• wq writes the changes, and then quits

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The echo command

• Another way to create a small text file is to use
  echo
• echo repeats the text of its input to group
  several words together use double quotes
• Be redirecting output, echo can be used to create
  a new text file
• (alpha2) 3 echo "The quick brown fox jumped over
  the
• lazy dog" gt keytest.txt