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*helphelp.txt*  For Vim version 7.3.  Last change: 2010 Jul 29


                  VIM REFERENCE MANUAL    by Bram Moolenaar


Help on help files                                      *helphelp*

1. Help commands                |online-help|
2. Translating help files       |help-translated|
3. Writing help files           |help-writing|

==============================================================================
1. Help commands                                        *online-help*

                        *help* *<Help>* *:h* *:help* *<F1>* *i_<F1>* *i_<Help>*
<Help>          or
:h[elp]                 Open a window and display the help file in read-only
                        mode.  If there is a help window open already, use
                        that one.  Otherwise, if the current window uses the
                        full width of the screen or is at least 80 characters
                        wide, the help window will appear just above the
                        current window.  Otherwise the new window is put at
                        the very top.
                        The 'helplang' option is used to select a language, if
                        the main help file is available in several languages.
                        {not in Vi}

                                                *{subject}* *E149* *E661*
:h[elp] {subject}       Like ":help", additionally jump to the tag {subject}.
                        {subject} can include wildcards like "*", "?" and
                        "[a-z]":
                           :help z?     jump to help for any "z" command
                           :help z.     jump to the help for "z."
                        If there is no full match for the pattern, or there
                        are several matches, the "best" match will be used.
                        A sophisticated algorithm is used to decide which
                        match is better than another one.  These items are
                        considered in the computation:
                        - A match with same case is much better than a match
                          with different case.
                        - A match that starts after a non-alphanumeric
                          character is better than a match in the middle of a
                          word.
                        - A match at or near the beginning of the tag is
                          better than a match further on.
                        - The more alphanumeric characters match, the better.
                        - The shorter the length of the match, the better.

                        The 'helplang' option is used to select a language, if
                        the {subject} is available in several languages.
                        To find a tag in a specific language, append "@ab",
                        where "ab" is the two-letter language code.  See
                        |help-translated|.

                        Note that the longer the {subject} you give, the less
                        matches will be found.  You can get an idea how this
                        all works by using commandline completion (type CTRL-D
                        after ":help subject" |c_CTRL-D|).
                        If there are several matches, you can have them listed
                        by hitting CTRL-D.  Example: >
                                :help cont<Ctrl-D>

<                       Instead of typing ":help CTRL-V" to search for help
                        for CTRL-V you can type: >
                                :help ^V
<                       This also works together with other characters, for
                        example to find help for CTRL-V in Insert mode: >
                                :help i^V
<
                        To use a regexp |pattern|, first do ":help" and then
                        use ":tag {pattern}" in the help window.  The
                        ":tnext" command can then be used to jump to other
                        matches, "tselect" to list matches and choose one. >
                                :help index| :tse z.

<                       When there is no argument you will see matches for
                        "help", to avoid listing all possible matches (that
                        would be very slow).
                        The number of matches displayed is limited to 300.

                        This command can be followed by '|' and another
                        command, but you don't need to escape the '|' inside a
                        help command.  So these both work: >
                                :help |
                                :help k| only
<                       Note that a space before the '|' is seen as part of
                        the ":help" argument.
                        You can also use <LF> or <CR> to separate the help
                        command from a following command.  You need to type
                        CTRL-V first to insert the <LF> or <CR>.  Example: >
                                :help so<C-V><CR>only
<                       {not in Vi}

:h[elp]! [subject]      Like ":help", but in non-English help files prefer to
                        find a tag in a file with the same language as the
                        current file.  See |help-translated|.

                                                        *:helpg* *:helpgrep*
:helpg[rep] {pattern}[@xx]
                        Search all help text files and make a list of lines
                        in which {pattern} matches.  Jumps to the first match.
                        The optional [@xx] specifies that only matches in the
                        "xx" language are to be found.
                        You can navigate through the matches with the
                        |quickfix| commands, e.g., |:cnext| to jump to the
                        next one.  Or use |:cwindow| to get the list of
                        matches in the quickfix window.
                        {pattern} is used as a Vim regexp |pattern|.
                        'ignorecase' is not used, add "\c" to ignore case.
                        Example for case sensitive search: >
                                :helpgrep Uganda
<                       Example for case ignoring search: >
                                :helpgrep uganda\c
<                       Example for searching in French help: >
                                :helpgrep backspace@fr
<                       The pattern does not support line breaks, it must
                        match within one line.  You can use |:grep| instead,
                        but then you need to get the list of help files in a
                        complicated way.
                        Cannot be followed by another command, everything is
                        used as part of the pattern.  But you can use
                        |:execute| when needed.
                        Compressed help files will not be searched (Fedora
                        compresses the help files).
                        {not in Vi}

                                                        *:lh* *:lhelpgrep*
:lh[elpgrep] {pattern}[@xx]
                        Same as ":helpgrep", except the location list is used
                        instead of the quickfix list.  If the help window is
                        already opened, then the location list for that window
                        is used.  Otherwise, a new help window is opened and
                        the location list for that window is set.  The
                        location list for the current window is not changed.

                                                        *:exu* *:exusage*
:exu[sage]              Show help on Ex commands.  Added to simulate the Nvi
                        command. {not in Vi}

                                                        *:viu* *:viusage*
:viu[sage]              Show help on Normal mode commands.  Added to simulate
                        the Nvi command. {not in Vi}

When no argument is given to |:help| the file given with the 'helpfile' option
will be opened.  Otherwise the specified tag is searched for in all "doc/tags"
files in the directories specified in the 'runtimepath' option.

The initial height of the help window can be set with the 'helpheight' option
(default 20).

Jump to specific subjects by using tags.  This can be done in two ways:
- Use the "CTRL-]" command while standing on the name of a command or option.
  This only works when the tag is a keyword.  "<C-Leftmouse>" and
  "g<LeftMouse>" work just like "CTRL-]".
- use the ":ta {subject}" command.  This also works with non-keyword
  characters.

Use CTRL-T or CTRL-O to jump back.
Use ":q" to close the help window.

If there are several matches for an item you are looking for, this is how you
can jump to each one of them:
1. Open a help window
2. Use the ":tag" command with a slash prepended to the tag.  E.g.: >
        :tag /min
3. Use ":tnext" to jump to the next matching tag.

It is possible to add help files for plugins and other items.  You don't need
to change the distributed help files for that.  See |add-local-help|.

To write a local help file, see |write-local-help|.

Note that the title lines from the local help files are automagically added to
the "LOCAL ADDITIONS" section in the "help.txt" help file |local-additions|.
This is done when viewing the file in Vim, the file itself is not changed.  It
is done by going through all help files and obtaining the first line of each
file.  The files in $VIMRUNTIME/doc are skipped.

                                                        *help-xterm-window*
If you want to have the help in another xterm window, you could use this
command: >
        :!xterm -e vim +help &
<

                        *:helpfind* *:helpf*
:helpf[ind]             Like |:help|, but use a dialog to enter the argument.
                        Only for backwards compatibility.  It now executes the
                        ToolBar.FindHelp menu entry instead of using a builtin
                        dialog.  {only when compiled with |+GUI_GTK|}
<                       {not in Vi}

                                        *:helpt* *:helptags*
                                *E154* *E150* *E151* *E152* *E153* *E670*
:helpt[ags] [++t] {dir}
                        Generate the help tags file(s) for directory {dir}.
                        All "*.txt" and "*.??x" files in the directory are
                        scanned for a help tag definition in between stars.
                        The "*.??x" files are for translated docs, they
                        generate the "tags-??" file, see |help-translated|.
                        The generated tags files are sorted.
                        When there are duplicates an error message is given.
                        An existing tags file is silently overwritten.
                        The optional "++t" argument forces adding the
                        "help-tags" tag.  This is also done when the {dir} is
                        equal to $VIMRUNTIME/doc.
                        To rebuild the help tags in the runtime directory
                        (requires write permission there): >
                                :helptags $VIMRUNTIME/doc
<                       {not in Vi}


==============================================================================
2. Translated help files                                *help-translated*

It is possible to add translated help files, next to the original English help
files.  Vim will search for all help in "doc" directories in 'runtimepath'.
This is only available when compiled with the |+multi_lang| feature.

At this moment translations are available for:
        Chinese - multiple authors
        French  - translated by David Blanchet
        Italian - translated by Antonio Colombo
        Polish  - translated by Mikolaj Machowski
        Russian - translated by Vassily Ragosin
See the Vim website to find them: http://www.vim.org/translations.php

A set of translated help files consists of these files:

        help.abx
        howto.abx
        ...
        tags-ab

"ab" is the two-letter language code.  Thus for Italian the names are:

        help.itx
        howto.itx
        ...
        tags-it

The 'helplang' option can be set to the preferred language(s).  The default is
set according to the environment.  Vim will first try to find a matching tag
in the preferred language(s).  English is used when it cannot be found.

To find a tag in a specific language, append "@ab" to a tag, where "ab" is the
two-letter language code.  Example: >
        :he user-manual@it
        :he user-manual@en
The first one finds the Italian user manual, even when 'helplang' is empty.
The second one finds the English user manual, even when 'helplang' is set to
"it".

When using command-line completion for the ":help" command, the "@en"
extension is only shown when a tag exists for multiple languages.  When the
tag only exists for English "@en" is omitted.

When using |CTRL-]| or ":help!" in a non-English help file Vim will try to
find the tag in the same language.  If not found then 'helplang' will be used
to select a language.

Help files must use latin1 or utf-8 encoding.  Vim assumes the encoding is
utf-8 when finding non-ASCII characters in the first line.  Thus you must
translate the header with "For Vim version".

The same encoding must be used for the help files of one language in one
directory.  You can use a different encoding for different languages and use
a different encoding for help files of the same language but in a different
directory.

Hints for translators:
- Do not translate the tags.  This makes it possible to use 'helplang' to
  specify the preferred language.  You may add new tags in your language.
- When you do not translate a part of a file, add tags to the English version,
  using the "tag@en" notation.
- Make a package with all the files and the tags file available for download.
  Users can drop it in one of the "doc" directories and start use it.
  Report this to Bram, so that he can add a link on www.vim.org.
- Use the |:helptags| command to generate the tags files.  It will find all
  languages in the specified directory.

==============================================================================
3. Writing help files                                   *help-writing*

For ease of use, a Vim help file for a plugin should follow the format of the
standard Vim help files.  If you are writing a new help file it's best to copy
one of the existing files and use it as a template.

The first line in a help file should have the following format:

*helpfile_name.txt*     For Vim version 7.3     Last change: 2010 June 4

The first field is a link to the help file name.  The second field describes
the applicable Vim version.  The last field specifies the last modification
date of the file.  Each field is separated by a tab.

At the bottom of the help file, place a Vim modeline to set the 'textwidth'
and 'tabstop' options and the 'filetype' to 'help'.  Never set a global option
in such a modeline, that can have consequences undesired by whoever reads that
help.


TAGS

To define a help tag, place the name between asterisks (*tag-name*).  The
tag-name should be different from all the Vim help tag names and ideally
should begin with the name of the Vim plugin.  The tag name is usually right
aligned on a line.

When referring to an existing help tag and to create a hot-link, place the
name between two bars (|) eg. |help-writing|.

When referring to a Vim option in the help file, place the option name between
two single quotes, eg. 'statusline'


HIGHLIGHTING

To define a column heading, use a tilde character at the end of the line.
This will highlight the column heading in a different color.  E.g.

Column heading~

To separate sections in a help file, place a series of '=' characters in a
line starting from the first column.  The section separator line is highlighted
differently.

To quote a block of ex-commands verbatim, place a greater than (>) character
at the end of the line before the block and a less than (<) character as the
first non-blank on a line following the block.  Any line starting in column 1
also implicitly stops the block of ex-commands before it.  E.g. >
    function Example_Func()
        echo "Example"
    endfunction
<

The following are highlighted differently in a Vim help file:
  - a special key name expressed either in <> notation as in <PageDown>, or
    as a Ctrl character as in CTRL-X
  - anything between {braces}, e.g. {lhs} and {rhs}

The word "Note", "Notes" and similar automagically receive distinctive
highlighting.  So do these:
        *Todo   something to do
        *Error  something wrong

You can find the details in $VIMRUNTIME/syntax/help.vim

 vim:tw=78:ts=8:ft=help:norl: