1. Text Editing February 2 nd, 2004 Class Meeting 3

2. Text Editing Last week, you learned to manipulate files in the file system ( cp, mv, rm, ln ) and to view their contents ( cat, more ) How do you modify the contents of files? Unix editors work with plain ASCII text files: vi, emacs, pico Windows systems use their own window- based editors: Notepad, Wordpad

3. Why vi ? Availability included on practically all Unix/Linux systems Command-line editor, allowing use with remote login Simple and powerful

4. vi Basics Invoke with: vi [filename(s)] Editor takes over screen Various modes: command mode – characters send commands to editor (saving, quitting, searching, replacing) insert mode append mode change mode typing changes the text

5. Command Mode vi starts in this mode From other modes, typing Esc will enter command mode Commands for: Cursor movement Editing File operations Searching Entering other modes

6. Cursor Movement Up: k Down: j Left: h Right: l Larger Movements n{j|k|l|h} – move n characters/lines up/down/left/right Ctrl-F, Ctrl-B – page down, page up w – move to the beginning of the word :n – move to line n 0, $ – move to beginning or end of file

7. Editing Commands u – undo last typing x – delete current character dd – delete current line dw – delete current word rx – replace current character with x yy – copy current line p – paste copied/deleted items J – join two lines can be preceded by a number to perform operation multiple times

8. File Operations ZZ, :wq – save and quit :w – save :w – save as :q – quit :q! – quit without saving :e – load another file :n – load next file

9. Search /string – search for string ?string – search backwards for string n – repeat previous search N – repeat search in opposite direction % – find match of current (,[, or {

10. Entering Modes from Command Mode i – insert text before current character I – insert text at beginning of line a – append text after current character A – append text at end of the line o – open line above current line O – open line below current line cw – change (overwrite) current word C – change text after cursor

11. Additional Info Unix in a Nutshell – Chapter 8 lists all vi commands vi uses all lowercase letters except ‘v’ (and many uppercase characters and punctuation) for commands Be careful! Learn undo commands emacs is covered in Chapter 7

12. More Shell Commands ps – list current processes top – dynamic display of system’s utilization by processes kill – terminate a process time – keep timing information for a process