UNIX Text Editing (EMACS and VI)

  A text editor is used to create or modify any file containing printable text. For example, the file could be a C program source or input data. There are a few text editors available on UNIX, the editors are:

• EMACS -- Gnu's version of EMACS - GNU EMACS - Within this editor typing ctrl-H will invoke its comprehensive online help. It also has an online tutorial for interested users (ctrl-H t). There is a one page reference sheet in the EDLAB on GNU Emacs. Invoke by typing: emacs filename. To exit, type ^X^C, and reply y to save the file. To quit, abandoning the changes you have made, type ^X^C, and reply n to not save the file, but then reply yes to quit.

  For more commands see the emacs reference card, included at the end of this manual.
  

• VI -- VI is a screen oriented (visual) display editor. The VI manual pages are accessable by typing: man vi. The VI Beginner's Reference Card provides details of using this editor. Invoke by typing: vi filename.

  While in the editor pressing the i key puts the user in the mode for inserting text. To get back into the vi command mode press the <ESC> key or ctrl-[. To get to the ex command mode type the colon (:) key. Some basic ex commands are:

  r read the specified file into the buffer

  w write the contents of the buffer to the file filename

  q quit vi

  s searches for a match against the specified regular expression

  r! when followed by a shell command inserts the output of that command into the file (after the curent line)

  It is possible to create a file called .exrc that contains the settings and initial commands that are executed every time vi is invoked. Refer to the section on Setting Up Your Environment for a sample of this file.