The VI command set is based on the idea of combining motion commands with other commands. The motion command is used as a text region specifier for other commands. We classify motion commands into point commands and line commands.
The point commands are:
The line commands are:
Text Deletion Commands (see Deleting Text), Change commands (see Changing Text), even Shell Commands (see Shell Commands) use these commands to describe a region of text to operate on.
Viper adds two region descriptors, r and R. These describe the Emacs regions (see Basics), but they are not movement commands.
The command description uses angle brackets `
<>' to indicate
metasyntactic variables, since the normal conventions of using simple
text can be confusing with Viper where the commands themselves are
characters. Watch out where < shift commands and <count> are
<move>' refers to the above movement commands, and `
refers to registers or textmarkers from `
a' to `
that the `
<move>' is described by full move commands, that is to
say they will take counts, and otherwise behave like normal move commands.
<address>' refers to Ex line addresses, which include
|. <No address>|
|.+n .-n||Add or subtract for current line|
|number||Actual line number, use .= to get the line number|
|x,y||Where x and y are one of the above|
|%||For the whole file, same as (1,$).|
|Next or previous line with pattern <pat>.
Note that the pattern is allowed to contain newline character (inserted as C-qC-j). Therefore, one can search for patterns that span several lines.
Note that `
%' is used in Ex commands to mean current file. If you
want a `
%' in your command, it must be escaped as `
#' expands to the previous file. The previous file is
the first file in :args listing. This defaults to previous window
in the VI sense if you have one window only.
Others like `
<args> -- arguments', `
<cmd> -- command' etc.
should be fairly obvious.
Common characters referred to include:
We also use `
word' for alphanumeric/non-alphanumeric words, and
WORD' for whitespace delimited words. `
char' refers to any
ASCII character, `
CHAR' to non-whitespace character.
' indicate optional parameters; `
optional, usually defaulting to 1. Brackets are elided for
<count>' to eschew obfuscation.
Viper's idea of Vi's words is slightly different from Vi. First, Viper words understand Emacs symbol tables. Therefore, all symbols declared to be alphanumeric in a symbol table can automatically be made part of the Viper word. This is useful when, for instance, editing text containing European, Cyrillic, Japanese, etc., texts.
Second, Viper lets you depart from Vi's idea of a word by changing the a
syntax preference via the customization widget (the variable
viper-syntax-preference) or by executing
By default, Viper syntax preference is
reformed-vi, which means that
Viper considers only those symbols to be part of a word that are specified
as word-symbols by the current Emacs syntax table (which may be different
for different major modes) plus the underscore symbol _, minus the
symbols that are not considered words in Vi (e.g., `,',;, etc.), but may be
considered as word-symbols by various Emacs major modes. Reformed-Vi works
very close to Vi, and it also recognizes words in other
alphabets. Therefore, this is the most appropriate mode for editing text
and is likely to fit all your needs.
You can also set Viper syntax preference to
strict-vi, which would
cause Viper to view all non-English letters as non-word-symbols.
You can also specify
emacs as your preference, which would
make Viper use exactly the same notion of a word as Emacs does. In
particular, the underscore may not be part of a word in some major modes.
viper-syntax-preference is set to
words would consist of characters that are classified as alphanumeric
or as parts of symbols. This is convenient for editing programs.
viper-syntax-preference is a local variable, so it can have different
values for different major modes. For instance, in programming modes it can
have the value
extended. In text modes where words contain special
characters, such as European (non-English) letters, Cyrillic letters, etc.,
the value can be
If you consider using different syntactic preferences for different major
modes, you should execute, for example,
(viper-set-syntax-preference nil "extended")
in the appropriate major mode hooks.
The above discussion concerns only the movement commands. In regular
expressions, words remain the same as in Emacs. That is, the expressions
\<, etc., use Emacs' idea of what is a word,
and they don't look into the value of variable
viper-syntax-preference. This is because Viper avoids changing
syntax tables in order to not thwart the various major modes that set these
The usual Emacs convention is used to indicate Control Characters, i.e C-h for Control-h. Do not confuse this to mean the separate characters C - h!!! The ^ is itself, never used to indicate a Control character.
Finally, we note that Viper's Ex-style commands can be made to work on the current Emacs region. This is done by typing a digit argument before :. For instance, typing 1: will propmt you with something like :123,135, assuming that the current region starts at line 123 and ends at line 135. There is no need to type the line numbers, since Viper inserts them automatically in front of the Ex command.Commands Commands Text Handling