vi

Vi has two modes insertion mode and command mode. The editor begins in command mode, where the cursor movement and text deletion and pasting occur. Insertion mode begins upon entering an insertion or change command. [ESC] returns the editor to command mode (where you can quit, for example by typing :q!). Most commands execute as soon as you type them except for “colon” commands which execute when you press the return key.

Almost all deletion commands are performed by typing d followed by a motion. For example, dw deletes a word. A few other deletes are:

Like deletion, almost all yank commands are performed by typing y followed by a motion. For example, y$ yanks to the end of the line. Two other yank commands are:

The change command is a deletion command that leaves the editor in insert mode. It is performed by typing c followed by a motion. For example cw changes a word. A few other change commands are:

Named buffers may be specified before any deletion, change, yank or put command. The general prefix has the form “c where c is any lowercase character. for example, “adw deletes a word into buffer a. It may thereafter be put back into text with an appropriate “ap.

Named markers may be set on any line in a file. Any lower case letter may be a marker name. Markers may also be used as limits for ranges.

The search and replace function is accomplished with the :s command. It is commonly used in combination with ranges or the :g command (below).

| Command | Description | | ------------- | -------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ | | /Hello/ | Matches if the line contains the value Hello | | /^TEST$/ | Matches if the line contains TEST by itself | | /^[a-zA-Z]/ | Matches if the line starts with any letter | | /^[a-z].*/ | Matches if the first character of the line is a-z and there is at least one more of any character following it | | /2134$/ | Matches if line ends with 2134 | | /\(21 | 35\)/ | Matches is the line contains 21 or 35 Note the use of ( ) with the pipe symbol to specify the ‘or’ condition | | /[0-9]*/ | Matches if there are zero or more numbers in the line | | /^[^#]/ | Matches if the first character is not a # in the line |

Notes:

Nearly every command may be preceded by a number that specifies how many times it is to be performed. For example, 5dw will delete 5 words and 3fe will move the cursor forward to the 3rd occurrence of the letter e. Even insertions may be repeated conveniently with this method, say to insert the same line 100 times.

Ranges may precede most “colon” commands and cause them to be executed on a line or lines. For example :3,7d would delete lines 3-7. Ranges are commonly combined with the :s command to perform a replacement on several lines, as with :.,$s/pattern/string/g to make a replacement from the current line to the end of the file.