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autocmd - Vim Documentation

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autocmd.txt   For Vim version 8.0.  Last change: 2017 Apr 07

                  VIM REFERENCE MANUAL    by Bram Moolenaar

Automatic commands                                      autocommand

For a basic explanation, see section 40.3 in the user manual.

1.  Introduction                autocmd-intro
2.  Defining autocommands       autocmd-define
3.  Removing autocommands       autocmd-remove
4.  Listing autocommands        autocmd-list
5.  Events                      autocmd-events
6.  Patterns                    autocmd-patterns
7.  Buffer-local autocommands   autocmd-buflocal
8.  Groups                      autocmd-groups
9.  Executing autocommands      autocmd-execute
10. Using autocommands          autocmd-use
11. Disabling autocommands      autocmd-disable

{Vi does not have any of these commands}
{only when the +autocmd feature has not been disabled at compile time}

1. Introduction                                         autocmd-intro

You can specify commands to be executed automatically when reading or writing
a file, when entering or leaving a buffer or window, and when exiting Vim.
For example, you can create an autocommand to set the 'cindent' option for
files matching *.c.  You can also use autocommands to implement advanced
features, such as editing compressed files (see gzip-example).  The usual
place to put autocommands is in your .vimrc or .exrc file.

                                        E203 E204 E143 E855 E937
WARNING: Using autocommands is very powerful, and may lead to unexpected side
effects.  Be careful not to destroy your text.
- It's a good idea to do some testing on an expendable copy of a file first.
  For example: If you use autocommands to decompress a file when starting to
  edit it, make sure that the autocommands for compressing when writing work
- Be prepared for an error halfway through (e.g., disk full).  Vim will mostly
  be able to undo the changes to the buffer, but you may have to clean up the
  changes to other files by hand (e.g., compress a file that has been
- If the BufRead* events allow you to edit a compressed file, the FileRead*
  events should do the same (this makes recovery possible in some rare cases).
  It's a good idea to use the same autocommands for the File* and Buf* events
  when possible.

2. Defining autocommands                                autocmd-define

                                                        :au :autocmd
:au[tocmd] [group] {event} {pat} [nested] {cmd}
                        Add {cmd} to the list of commands that Vim will
                        execute automatically on {event} for a file matching
                        {pat} autocmd-patterns.
                        Vim always adds the {cmd} after existing autocommands,
                        so that the autocommands execute in the order in which
                        they were given.  See autocmd-nested for [nested].

The special pattern <buffer> or <buffer=N> defines a buffer-local autocommand.
See autocmd-buflocal.

Note: The ":autocmd" command can only be followed by another command when the
'|' appears before {cmd}.  This works:
        :augroup mine | au! BufRead | augroup END
But this sees "augroup" as part of the defined command:
        :augroup mine | au BufRead * set tw=70 | augroup END

Note that special characters (e.g., "%", "<cword>") in the ":autocmd"
arguments are not expanded when the autocommand is defined.  These will be
expanded when the Event is recognized, and the {cmd} is executed.  The only
exception is that "<sfile>" is expanded when the autocmd is defined.  Example:

        :au BufNewFile,BufRead *.html so <sfile>:h/html.vim

Here Vim expands <sfile> to the name of the file containing this line.

:autocmd adds to the list of autocommands regardless of whether they are
already present.  When your .vimrc file is sourced twice, the autocommands
will appear twice.  To avoid this, define your autocommands in a group, so
that you can easily clear them:

        augroup vimrc
          autocmd!      " Remove all vimrc autocommands
          au BufNewFile,BufRead *.html so <sfile>:h/html.vim
        augroup END

If you don't want to remove all autocommands, you can instead use a variable
to ensure that Vim includes the autocommands only once:

        :if !exists("autocommands_loaded")
        :  let autocommands_loaded = 1
        :  au ...

When the [group] argument is not given, Vim uses the current group (as defined
with ":augroup"); otherwise, Vim uses the group defined with [group].  Note
that [group] must have been defined before.  You cannot define a new group
with ":au group ..."; use ":augroup" for that.

While testing autocommands, you might find the 'verbose' option to be useful:
        :set verbose=9
This setting makes Vim echo the autocommands as it executes them.

When defining an autocommand in a script, it will be able to call functions
local to the script and use mappings local to the script.  When the event is
triggered and the command executed, it will run in the context of the script
it was defined in.  This matters if <SID> is used in a command.

When executing the commands, the message from one command overwrites a
previous message.  This is different from when executing the commands
manually.  Mostly the screen will not scroll up, thus there is no hit-enter
prompt.  When one command outputs two messages this can happen anyway.

3. Removing autocommands                                autocmd-remove

:au[tocmd]! [group] {event} {pat} [nested] {cmd}
                        Remove all autocommands associated with {event} and
                        {pat}, and add the command {cmd}.  See
                        autocmd-nested for [nested].

:au[tocmd]! [group] {event} {pat}
                        Remove all autocommands associated with {event} and

:au[tocmd]! [group] * {pat}
                        Remove all autocommands associated with {pat} for all

:au[tocmd]! [group] {event}
                        Remove ALL autocommands for {event}.
                        Warning: You should not do this without a group for
                        BufRead and other common events, it can break
                        plugins, syntax highlighting, etc.

:au[tocmd]! [group]     Remove ALL autocommands.
                        Warning: You should normally not do this without a
                        group, it breaks plugins, syntax highlighting, etc.

When the [group] argument is not given, Vim uses the current group (as defined
with ":augroup"); otherwise, Vim uses the group defined with [group].

4. Listing autocommands                                 autocmd-list

:au[tocmd] [group] {event} {pat}
                        Show the autocommands associated with {event} and

:au[tocmd] [group] * {pat}
                        Show the autocommands associated with {pat} for all

:au[tocmd] [group] {event}
                        Show all autocommands for {event}.

:au[tocmd] [group]      Show all autocommands.

If you provide the [group] argument, Vim lists only the autocommands for
[group]; otherwise, Vim lists the autocommands for ALL groups.  Note that this
argument behavior differs from that for defining and removing autocommands.

In order to list buffer-local autocommands, use a pattern in the form <buffer>
or <buffer=N>.  See autocmd-buflocal.

When 'verbose' is non-zero, listing an autocommand will also display where it
was last defined. Example:

    :verbose autocmd BufEnter
    FileExplorer  BufEnter
        *         call s:LocalBrowse(expand("<amatch>"))
            Last set from /usr/share/vim/vim-7.0/plugin/NetrwPlugin.vim

See :verbose-cmd for more information.

5. Events                                       autocmd-events E215 E216

You can specify a comma-separated list of event names.  No white space can be
used in this list.  The command applies to all the events in the list.

For READING FILES there are four kinds of events possible:
        BufNewFile                      starting to edit a non-existent file
        BufReadPre      BufReadPost     starting to edit an existing file
        FilterReadPre   FilterReadPost  read the temp file with filter output
        FileReadPre     FileReadPost    any other file read
Vim uses only one of these four kinds when reading a file.  The "Pre" and
"Post" events are both triggered, before and after reading the file.

Note that the autocommands for the *ReadPre events and all the Filter events
are not allowed to change the current buffer (you will get an error message if
this happens).  This is to prevent the file to be read into the wrong buffer.

Note that the 'modified' flag is reset AFTER executing the BufReadPost
and BufNewFile autocommands.  But when the 'modified' option was set by the
autocommands, this doesn't happen.

You can use the 'eventignore' option to ignore a number of events or all
                                        autocommand-events {event}
Vim recognizes the following events.  Vim ignores the case of event names
(e.g., you can use "BUFread" or "bufread" instead of "BufRead").

First an overview by function with a short explanation.  Then the list
alphabetically with full explanations autocmd-events-abc.

Name                    triggered by

BufNewFile            starting to edit a file that doesn't exist
BufReadPre            starting to edit a new buffer, before reading the file
BufRead               starting to edit a new buffer, after reading the file
BufReadPost           starting to edit a new buffer, after reading the file
BufReadCmd            before starting to edit a new buffer Cmd-event

FileReadPre           before reading a file with a ":read" command
FileReadPost          after reading a file with a ":read" command
FileReadCmd           before reading a file with a ":read" command Cmd-event

FilterReadPre         before reading a file from a filter command
FilterReadPost        after reading a file from a filter command

StdinReadPre          before reading from stdin into the buffer
StdinReadPost         After reading from the stdin into the buffer

BufWrite              starting to write the whole buffer to a file
BufWritePre           starting to write the whole buffer to a file
BufWritePost          after writing the whole buffer to a file
BufWriteCmd           before writing the whole buffer to a file Cmd-event

FileWritePre          starting to write part of a buffer to a file
FileWritePost         after writing part of a buffer to a file
FileWriteCmd          before writing part of a buffer to a file Cmd-event

FileAppendPre         starting to append to a file
FileAppendPost        after appending to a file
FileAppendCmd         before appending to a file Cmd-event

FilterWritePre        starting to write a file for a filter command or diff
FilterWritePost       after writing a file for a filter command or diff

BufAdd                just after adding a buffer to the buffer list
BufCreate             just after adding a buffer to the buffer list
BufDelete             before deleting a buffer from the buffer list
BufWipeout            before completely deleting a buffer

BufFilePre            before changing the name of the current buffer
BufFilePost           after changing the name of the current buffer

BufEnter              after entering a buffer
BufLeave              before leaving to another buffer
BufWinEnter           after a buffer is displayed in a window
BufWinLeave           before a buffer is removed from a window

BufUnload             before unloading a buffer
BufHidden             just after a buffer has become hidden
BufNew                just after creating a new buffer

SwapExists            detected an existing swap file

FileType              when the 'filetype' option has been set
Syntax                when the 'syntax' option has been set
EncodingChanged       after the 'encoding' option has been changed
TermChanged           after the value of 'term' has changed
OptionSet             after setting any option

        Startup and exit
VimEnter              after doing all the startup stuff
GUIEnter              after starting the GUI successfully
GUIFailed             after starting the GUI failed
TermResponse          after the terminal response to t_RV is received

QuitPre               when using :quit, before deciding whether to quit
VimLeavePre           before exiting Vim, before writing the viminfo file
VimLeave              before exiting Vim, after writing the viminfo file

FileChangedShell      Vim notices that a file changed since editing started
FileChangedShellPost  After handling a file changed since editing started
FileChangedRO         before making the first change to a read-only file

ShellCmdPost          after executing a shell command
ShellFilterPost       after filtering with a shell command

CmdUndefined          a user command is used but it isn't defined
FuncUndefined         a user function is used but it isn't defined
SpellFileMissing      a spell file is used but it can't be found
SourcePre             before sourcing a Vim script
SourceCmd             before sourcing a Vim script Cmd-event

VimResized            after the Vim window size changed
FocusGained           Vim got input focus
FocusLost             Vim lost input focus
CursorHold            the user doesn't press a key for a while
CursorHoldI           the user doesn't press a key for a while in Insert mode
CursorMoved           the cursor was moved in Normal mode
CursorMovedI          the cursor was moved in Insert mode

WinNew                after creating a new window
TabNew                after creating a new tab page
TabClosed             after closing a tab page
WinEnter              after entering another window
WinLeave              before leaving a window
TabEnter              after entering another tab page
TabLeave              before leaving a tab page
CmdwinEnter           after entering the command-line window
CmdwinLeave           before leaving the command-line window

InsertEnter           starting Insert mode
InsertChange          when typing <Insert> while in Insert or Replace mode
InsertLeave           when leaving Insert mode
InsertCharPre         when a character was typed in Insert mode, before
                        inserting it

TextChanged           after a change was made to the text in Normal mode
TextChangedI          after a change was made to the text in Insert mode

ColorScheme           after loading a color scheme

RemoteReply           a reply from a server Vim was received

QuickFixCmdPre        before a quickfix command is run
QuickFixCmdPost       after a quickfix command is run

SessionLoadPost       after loading a session file

MenuPopup             just before showing the popup menu
CompleteDone          after Insert mode completion is done

User                  to be used in combination with ":doautocmd"

The alphabetical list of autocommand events:            autocmd-events-abc

                                                        BufCreate BufAdd
BufAdd or BufCreate             Just after creating a new buffer which is
                                added to the buffer list, or adding a buffer
                                to the buffer list.
                                Also used just after a buffer in the buffer
                                list has been renamed.
                                The BufCreate event is for historic reasons.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being created "<afile>".
BufDelete                       Before deleting a buffer from the buffer list.
                                The BufUnload may be called first (if the
                                buffer was loaded).
                                Also used just before a buffer in the buffer
                                list is renamed.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being deleted "<afile>" and "<abuf>".
                                Don't change to another buffer, it will cause
BufEnter                        After entering a buffer.  Useful for setting
                                options for a file type.  Also executed when
                                starting to edit a buffer, after the
                                BufReadPost autocommands.
BufFilePost                     After changing the name of the current buffer
                                with the ":file" or ":saveas" command.
BufFilePre                      Before changing the name of the current buffer
                                with the ":file" or ":saveas" command.
BufHidden                       Just after a buffer has become hidden.  That
                                is, when there are no longer windows that show
                                the buffer, but the buffer is not unloaded or
                                deleted.  Not used for ":qa" or ":q" when
                                exiting Vim.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being unloaded "<afile>".
BufLeave                        Before leaving to another buffer.  Also when
                                leaving or closing the current window and the
                                new current window is not for the same buffer.
                                Not used for ":qa" or ":q" when exiting Vim.
BufNew                          Just after creating a new buffer.  Also used
                                just after a buffer has been renamed.  When
                                the buffer is added to the buffer list BufAdd
                                will be triggered too.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being created "<afile>".
BufNewFile                      When starting to edit a file that doesn't
                                exist.  Can be used to read in a skeleton
                                                BufRead BufReadPost
BufRead or BufReadPost          When starting to edit a new buffer, after
                                reading the file into the buffer, before
                                executing the modelines.  See BufWinEnter
                                for when you need to do something after
                                processing the modelines.
                                This does NOT work for ":r file".  Not used
                                when the file doesn't exist.  Also used after
                                successfully recovering a file.
                                Also triggered for the filetypedetect group
                                when executing ":filetype detect" and when
                                writing an unnamed buffer in a way that the
                                buffer gets a name.
BufReadCmd                      Before starting to edit a new buffer.  Should
                                read the file into the buffer. Cmd-event
                                                BufReadPre E200 E201
BufReadPre                      When starting to edit a new buffer, before
                                reading the file into the buffer.  Not used
                                if the file doesn't exist.
BufUnload                       Before unloading a buffer.  This is when the
                                text in the buffer is going to be freed.  This
                                may be after a BufWritePost and before a
                                BufDelete.  Also used for all buffers that are
                                loaded when Vim is going to exit.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being unloaded "<afile>".
                                Don't change to another buffer or window, it
                                will cause problems!
                                When exiting and v:dying is 2 or more this
                                event is not triggered.
BufWinEnter                     After a buffer is displayed in a window.  This
                                can be when the buffer is loaded (after
                                processing the modelines) or when a hidden
                                buffer is displayed in a window (and is no
                                longer hidden).
                                Does not happen for :split without
                                arguments, since you keep editing the same
                                buffer, or ":split" with a file that's already
                                open in a window, because it re-uses an
                                existing buffer.  But it does happen for a
                                ":split" with the name of the current buffer,
                                since it reloads that buffer.
BufWinLeave                     Before a buffer is removed from a window.
                                Not when it's still visible in another window.
                                Also triggered when exiting.  It's triggered
                                before BufUnload or BufHidden.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being unloaded "<afile>".
                                When exiting and v:dying is 2 or more this
                                event is not triggered.
BufWipeout                      Before completely deleting a buffer.  The
                                BufUnload and BufDelete events may be called
                                first (if the buffer was loaded and was in the
                                buffer list).  Also used just before a buffer
                                is renamed (also when it's not in the buffer
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer being deleted "<afile>".
                                Don't change to another buffer, it will cause
                                                BufWrite BufWritePre
BufWrite or BufWritePre         Before writing the whole buffer to a file.
BufWriteCmd                     Before writing the whole buffer to a file.
                                Should do the writing of the file and reset
                                'modified' if successful, unless '+' is in
                                'cpo' and writing to another file cpo-+.
                                The buffer contents should not be changed.
                                When the command resets 'modified' the undo
                                information is adjusted to mark older undo
                                states as 'modified', like :write does.
BufWritePost                    After writing the whole buffer to a file
                                (should undo the commands for BufWritePre).
CmdUndefined                    When a user command is used but it isn't
                                defined.  Useful for defining a command only
                                when it's used.  The pattern is matched
                                against the command name.  Both <amatch> and
                                <afile> are set to the name of the command.
                                NOTE: Autocompletion won't work until the
                                command is defined.  An alternative is to
                                always define the user command and have it
                                invoke an autoloaded function.  See autoload.
CmdwinEnter                     After entering the command-line window.
                                Useful for setting options specifically for
                                this special type of window.  This is
                                triggered _instead_ of BufEnter and WinEnter.
                                <afile> is set to a single character,
                                indicating the type of command-line.
CmdwinLeave                     Before leaving the command-line window.
                                Useful to clean up any global setting done
                                with CmdwinEnter.  This is triggered _instead_
                                of BufLeave and WinLeave.
                                <afile> is set to a single character,
                                indicating the type of command-line.
ColorScheme                     After loading a color scheme. :colorscheme
                                The pattern is matched against the
                                colorscheme name. <afile> can be used for the
                                name of the actual file where this option was
                                set, and <amatch> for the new colorscheme

CompleteDone                    After Insert mode completion is done.  Either
                                when something was completed or abandoning
                                completion. ins-completion
                                The v:completed_item variable contains
                                information about the completed item.

CursorHold                      When the user doesn't press a key for the time
                                specified with 'updatetime'.  Not re-triggered
                                until the user has pressed a key (i.e. doesn't
                                fire every 'updatetime' ms if you leave Vim to
                                make some coffee. :)  See CursorHold-example
                                for previewing tags.
                                This event is only triggered in Normal mode.
                                It is not triggered when waiting for a command
                                argument to be typed, or a movement after an
                                While recording the CursorHold event is not
                                triggered. q
                                Internally the autocommand is triggered by the
                                <CursorHold> key. In an expression mapping
                                getchar() may see this character.

                                Note: Interactive commands cannot be used for
                                this event.  There is no hit-enter prompt,
                                the screen is updated directly (when needed).
                                Note: In the future there will probably be
                                another option to set the time.
                                Hint: to force an update of the status lines
                                        :let &ro = &ro
                                {only on Amiga, Unix, Win32, MSDOS and all GUI
CursorHoldI                     Just like CursorHold, but in Insert mode.
                                Not triggered when waiting for another key,
                                e.g. after CTRL-V, and not when in CTRL-X mode

CursorMoved                     After the cursor was moved in Normal or Visual
                                mode.  Also when the text of the cursor line
                                has been changed, e.g., with "x", "rx" or "p".
                                Not triggered when there is typeahead or when
                                an operator is pending.
                                For an example see match-parens.
                                Careful: This is triggered very often, don't
                                do anything that the user does not expect or
                                that is slow.
CursorMovedI                    After the cursor was moved in Insert mode.
                                Not triggered when the popup menu is visible.
                                Otherwise the same as CursorMoved.
EncodingChanged                 Fires off after the 'encoding' option has been
                                changed.  Useful to set up fonts, for example.
FileAppendCmd                   Before appending to a file.  Should do the
                                appending to the file.  Use the '[ and ']
                                marks for the range of lines.Cmd-event
FileAppendPost                  After appending to a file.
FileAppendPre                   Before appending to a file.  Use the '[ and ']
                                marks for the range of lines.
FileChangedRO                   Before making the first change to a read-only
                                file.  Can be used to check-out the file from
                                a source control system.  Not triggered when
                                the change was caused by an autocommand.
                                This event is triggered when making the first
                                change in a buffer or the first change after
                                'readonly' was set, just before the change is
                                applied to the text.
                                WARNING: If the autocommand moves the cursor
                                the effect of the change is undefined.
                                It is not allowed to change to another buffer
                                here.  You can reload the buffer but not edit
                                another one.
                                If the number of lines changes saving for undo
                                may fail and the change will be aborted.
FileChangedShell                When Vim notices that the modification time of
                                a file has changed since editing started.
                                Also when the file attributes of the file
                                change or when the size of the file changes.
                                Mostly triggered after executing a shell
                                command, but also with a :checktime command
                                or when gvim regains input focus.
                                This autocommand is triggered for each changed
                                file.  It is not used when 'autoread' is set
                                and the buffer was not changed.  If a
                                FileChangedShell autocommand is present the
                                warning message and prompt is not given.
                                The v:fcs_reason variable is set to indicate
                                what happened and v:fcs_choice can be used
                                to tell Vim what to do next.
                                NOTE: When this autocommand is executed, the
                                current buffer "%" may be different from the
                                buffer that was changed, which is in "<afile>".
                                NOTE: The commands must not change the current
                                buffer, jump to another buffer or delete a
                                buffer.  E246 E811
                                NOTE: This event never nests, to avoid an
                                endless loop.  This means that while executing
                                commands for the FileChangedShell event no
                                other FileChangedShell event will be
FileChangedShellPost            After handling a file that was changed outside
                                of Vim.  Can be used to update the statusline.
FileEncoding                    Obsolete.  It still works and is equivalent
                                to EncodingChanged.
FileReadCmd                     Before reading a file with a ":read" command.
                                Should do the reading of the file. Cmd-event
FileReadPost                    After reading a file with a ":read" command.
                                Note that Vim sets the '[ and '] marks to the
                                first and last line of the read.  This can be
                                used to operate on the lines just read.
FileReadPre                     Before reading a file with a ":read" command.
FileType                        When the 'filetype' option has been set.  The
                                pattern is matched against the filetype.
                                <afile> can be used for the name of the file
                                where this option was set, and <amatch> for
                                the new value of 'filetype'.
                                See filetypes.
FileWriteCmd                    Before writing to a file, when not writing the
                                whole buffer.  Should do the writing to the
                                file.  Should not change the buffer.  Use the
                                '[ and '] marks for the range of lines.
FileWritePost                   After writing to a file, when not writing the
                                whole buffer.
FileWritePre                    Before writing to a file, when not writing the
                                whole buffer.  Use the '[ and '] marks for the
                                range of lines.
FilterReadPost                  After reading a file from a filter command.
                                Vim checks the pattern against the name of
                                the current buffer as with FilterReadPre.
                                Not triggered when 'shelltemp' is off.
                                                        FilterReadPre E135
FilterReadPre                   Before reading a file from a filter command.
                                Vim checks the pattern against the name of
                                the current buffer, not the name of the
                                temporary file that is the output of the
                                filter command.
                                Not triggered when 'shelltemp' is off.
FilterWritePost                 After writing a file for a filter command or
                                making a diff.
                                Vim checks the pattern against the name of
                                the current buffer as with FilterWritePre.
                                Not triggered when 'shelltemp' is off.
FilterWritePre                  Before writing a file for a filter command or
                                making a diff.
                                Vim checks the pattern against the name of
                                the current buffer, not the name of the
                                temporary file that is the output of the
                                filter command.
                                Not triggered when 'shelltemp' is off.
FocusGained                     When Vim got input focus.  Only for the GUI
                                version and a few console versions where this
                                can be detected.
FocusLost                       When Vim lost input focus.  Only for the GUI
                                version and a few console versions where this
                                can be detected.  May also happen when a
                                dialog pops up.
FuncUndefined                   When a user function is used but it isn't
                                defined.  Useful for defining a function only
                                when it's used.  The pattern is matched
                                against the function name.  Both <amatch> and
                                <afile> are set to the name of the function.
                                NOTE: When writing Vim scripts a better
                                alternative is to use an autoloaded function.
                                See autoload-functions.
GUIEnter                        After starting the GUI successfully, and after
                                opening the window.  It is triggered before
                                VimEnter when using gvim.  Can be used to
                                position the window from a .gvimrc file:
        :autocmd GUIEnter * winpos 100 50
GUIFailed                       After starting the GUI failed.  Vim may
                                continue to run in the terminal, if possible
                                (only on Unix and alikes, when connecting the
                                X server fails).  You may want to quit Vim:
        :autocmd GUIFailed * qall
InsertChange                    When typing <Insert> while in Insert or
                                Replace mode.  The v:insertmode variable
                                indicates the new mode.
                                Be careful not to move the cursor or do
                                anything else that the user does not expect.
InsertCharPre                   When a character is typed in Insert mode,
                                before inserting the char.
                                The v:char variable indicates the char typed
                                and can be changed during the event to insert
                                a different character.  When v:char is set
                                to more than one character this text is
                                inserted literally.
                                It is not allowed to change the text textlock.
                                The event is not triggered when 'paste' is
InsertEnter                     Just before starting Insert mode.  Also for
                                Replace mode and Virtual Replace mode.  The
                                v:insertmode variable indicates the mode.
                                Be careful not to do anything else that the
                                user does not expect.
                                The cursor is restored afterwards.  If you do
                                not want that set v:char to a non-empty
InsertLeave                     When leaving Insert mode.  Also when using
                                CTRL-O i_CTRL-O.  But not for i_CTRL-C.
MenuPopup                       Just before showing the popup menu (under the
                                right mouse button).  Useful for adjusting the
                                menu for what is under the cursor or mouse
                                The pattern is matched against a single
                                character representing the mode:
                                        n       Normal
                                        v       Visual
                                        o       Operator-pending
                                        i       Insert
                                        c       Command line
OptionSet                       After setting an option.  The pattern is
                                matched against the long option name.
                                The v:option_old variable indicates the
                                old option value, v:option_new variable
                                indicates the newly set value, the
                                v:option_type variable indicates whether
                                it's global or local scoped and <amatch>
                                indicates what option has been set.

                                Is not triggered on startup and for the 'key'
                                option for obvious reasons.

                                Usage example: Check for the existence of the
                                directory in the 'backupdir' and 'undodir'
                                options, create the directory if it doesn't
                                exist yet.

                                Note: It's a bad idea to reset an option
                                during this autocommand, this may break a
                                plugin. You can always use :noa to prevent
                                triggering this autocommand.

QuickFixCmdPre                  Before a quickfix command is run (:make,
                                The pattern is matched against the command
                                being run.  When :grep is used but 'grepprg'
                                is set to "internal" it still matches "grep".
                                This command cannot be used to set the
                                'makeprg' and 'grepprg' variables.
                                If this command causes an error, the quickfix
                                command is not executed.
QuickFixCmdPost                 Like QuickFixCmdPre, but after a quickfix
                                command is run, before jumping to the first
                                location. For :cfile and :lfile commands
                                it is run after error file is read and before
                                moving to the first error.
                                See QuickFixCmdPost-example.
QuitPre                         When using :quit:wq or :qall, before
                                deciding whether it closes the current window
                                or quits Vim.  Can be used to close any
                                non-essential window if the current window is
                                the last ordinary window.
RemoteReply                     When a reply from a Vim that functions as
                                server was received server2client().  The
                                pattern is matched against the {serverid}.
                                <amatch> is equal to the {serverid} from which
                                the reply was sent, and <afile> is the actual
                                reply string.
                                Note that even if an autocommand is defined,
                                the reply should be read with remote_read()
                                to consume it.
SessionLoadPost                 After loading the session file created using
                                the :mksession command.
ShellCmdPost                    After executing a shell command with :!cmd,
                                :shell:make and :grep.  Can be used to
                                check for any changed files.
ShellFilterPost                 After executing a shell command with
                                ":{range}!cmd", ":w !cmd" or ":r !cmd".
                                Can be used to check for any changed files.
SourcePre                       Before sourcing a Vim script. :source
                                <afile> is the name of the file being sourced.
SourceCmd                       When sourcing a Vim script. :source
                                <afile> is the name of the file being sourced.
                                The autocommand must source this file.
SpellFileMissing                When trying to load a spell checking file and
                                it can't be found.  The pattern is matched
                                against the language.  <amatch> is the
                                language, 'encoding' also matters.  See
StdinReadPost                   After reading from the stdin into the buffer,
                                before executing the modelines.  Only used
                                when the "-" argument was used when Vim was
                                started --.
StdinReadPre                    Before reading from stdin into the buffer.
                                Only used when the "-" argument was used when
                                Vim was started --.
SwapExists                      Detected an existing swap file when starting
                                to edit a file.  Only when it is possible to
                                select a way to handle the situation, when Vim
                                would ask the user what to do.
                                The v:swapname variable holds the name of
                                the swap file found, <afile> the file being
                                edited.  v:swapcommand may contain a command
                                to be executed in the opened file.
                                The commands should set the v:swapchoice
                                variable to a string with one character to
                                tell Vim what should be done next:
                                        'o'     open read-only
                                        'e'     edit the file anyway
                                        'r'     recover
                                        'd'     delete the swap file
                                        'q'     quit, don't edit the file
                                        'a'     abort, like hitting CTRL-C
                                When set to an empty string the user will be
                                asked, as if there was no SwapExists autocmd.
                                It is not allowed to change to another buffer,
                                change a buffer name or change directory
Syntax                          When the 'syntax' option has been set.  The
                                pattern is matched against the syntax name.
                                <afile> can be used for the name of the file
                                where this option was set, and <amatch> for
                                the new value of 'syntax'.
                                See :syn-on.
TabClosed                       After closing a tab page.
TabEnter                        Just after entering a tab page. tab-page
                                After triggering the WinEnter and before
                                triggering the BufEnter event.
TabLeave                        Just before leaving a tab page. tab-page
                                A WinLeave event will have been triggered
TabNew                          When a tab page was created. tab-page
                                A WinEnter event will have been triggered
                                first, TabEnter follows.
TermChanged                     After the value of 'term' has changed.  Useful
                                for re-loading the syntax file to update the
                                colors, fonts and other terminal-dependent
                                settings.  Executed for all loaded buffers.
TermResponse                    After the response to t_RV is received from
                                the terminal.  The value of v:termresponse
                                can be used to do things depending on the
                                terminal version.  Note that this event may be
                                triggered halfway executing another event,
                                especially if file I/O, a shell command or
                                anything else that takes time is involved.
TextChanged                     After a change was made to the text in the
                                current buffer in Normal mode.  That is when
                                b:changedtick has changed.
                                Not triggered when there is typeahead or when
                                an operator is pending.
                                Careful: This is triggered very often, don't
                                do anything that the user does not expect or
                                that is slow.
TextChangedI                    After a change was made to the text in the
                                current buffer in Insert mode.
                                Not triggered when the popup menu is visible.
                                Otherwise the same as TextChanged.
User                            Never executed automatically.  To be used for
                                autocommands that are only executed with
UserGettingBored                When the user presses the same key 42 times.
                                Just kidding! :-)
VimEnter                        After doing all the startup stuff, including
                                loading .vimrc files, executing the "-c cmd"
                                arguments, creating all windows and loading
                                the buffers in them.
                                Just before this event is triggered the
                                v:vim_did_enter variable is set, so that you
                                can do:
                                   if v:vim_did_enter
                                     call s:init()
                                     au VimEnter * call s:init()
VimLeave                        Before exiting Vim, just after writing the
                                .viminfo file.  Executed only once, like
                                To detect an abnormal exit use v:dying.
                                When v:dying is 2 or more this event is not
VimLeavePre                     Before exiting Vim, just before writing the
                                .viminfo file.  This is executed only once,
                                if there is a match with the name of what
                                happens to be the current buffer when exiting.
                                Mostly useful with a "*" pattern.
        :autocmd VimLeavePre * call CleanupStuff()
                                To detect an abnormal exit use v:dying.
                                When v:dying is 2 or more this event is not
VimResized                      After the Vim window was resized, thus 'lines'
                                and/or 'columns' changed.  Not when starting
                                up though.
WinEnter                        After entering another window.  Not done for
                                the first window, when Vim has just started.
                                Useful for setting the window height.
                                If the window is for another buffer, Vim
                                executes the BufEnter autocommands after the
                                WinEnter autocommands.
                                Note: When using ":split fname" the WinEnter
                                event is triggered after the split but before
                                the file "fname" is loaded.
WinLeave                        Before leaving a window.  If the window to be
                                entered next is for a different buffer, Vim
                                executes the BufLeave autocommands before the
                                WinLeave autocommands (but not for ":new").
                                Not used for ":qa" or ":q" when exiting Vim.

WinNew                          When a new window was created.  Not done for
                                the first window, when Vim has just started.
                                Before a WinEnter event.

6. Patterns                                     autocmd-patterns {pat}

The {pat} argument can be a comma separated list.  This works as if the
command was given with each pattern separately.  Thus this command:
        :autocmd BufRead *.txt,*.info set et
Is equivalent to:
        :autocmd BufRead *.txt set et
        :autocmd BufRead *.info set et

The file pattern {pat} is tested for a match against the file name in one of
two ways:
1. When there is no '/' in the pattern, Vim checks for a match against only
   the tail part of the file name (without its leading directory path).
2. When there is a '/' in the pattern, Vim checks for a match against both the
   short file name (as you typed it) and the full file name (after expanding
   it to a full path and resolving symbolic links).

The special pattern <buffer> or <buffer=N> is used for buffer-local
autocommands autocmd-buflocal.  This pattern is not matched against the name
of a buffer.

        :autocmd BufRead *.txt          set et
Set the 'et' option for all text files.

        :autocmd BufRead /vim/src/*.c   set cindent
Set the 'cindent' option for C files in the /vim/src directory.

        :autocmd BufRead /tmp/*.c       set ts=5
If you have a link from "/tmp/test.c" to "/home/nobody/vim/src/test.c", and
you start editing "/tmp/test.c", this autocommand will match.

Note:  To match part of a path, but not from the root directory, use a '*' as
the first character.  Example:
        :autocmd BufRead */doc/*.txt    set tw=78
This autocommand will for example be executed for "/tmp/doc/xx.txt" and
"/usr/home/piet/doc/yy.txt".  The number of directories does not matter here.

The file name that the pattern is matched against is after expanding
wildcards.  Thus if you issue this command:
        :e $ROOTDIR/main.$EXT
The argument is first expanded to:
Before it's matched with the pattern of the autocommand.  Careful with this
when using events like FileReadCmd, the value of <amatch> may not be what you

Environment variables can be used in a pattern:
        :autocmd BufRead $VIMRUNTIME/doc/*.txt  set expandtab
And ~ can be used for the home directory (if $HOME is defined):
        :autocmd BufWritePost ~/.vimrc   so ~/.vimrc
        :autocmd BufRead ~archive/*      set readonly
The environment variable is expanded when the autocommand is defined, not when
the autocommand is executed.  This is different from the command!

The pattern is interpreted like mostly used in file names:
        *       matches any sequence of characters; Unusual: includes path
        ?       matches any single character
        \?      matches a '?'
        .       matches a '.'
        ~       matches a '~'
        ,       separates patterns
        \,      matches a ','
        { }     like \( \) in a pattern
        ,       inside { }: like \| in a pattern
        \}      literal }
        \{      literal {
        \\\{n,m\}  like \{n,m} in a pattern
        \       special meaning like in a pattern
        [ch]    matches 'c' or 'h'
        [^ch]   match any character but 'c' and 'h'

Note that for all systems the '/' character is used for path separator (even
MS-DOS and OS/2).  This was done because the backslash is difficult to use
in a pattern and to make the autocommands portable across different systems.

It is possible to use pattern items, but they may not work as expected,
because of the translation done for the above.

Matching with the pattern is done when an event is triggered.  Changing the
buffer name in one of the autocommands, or even deleting the buffer, does not
change which autocommands will be executed.  Example:

        au BufEnter *.foo  bdel
        au BufEnter *.foo  set modified

This will delete the current buffer and then set 'modified' in what has become
the current buffer instead.  Vim doesn't take into account that "*.foo"
doesn't match with that buffer name.  It matches "*.foo" with the name of the
buffer at the moment the event was triggered.

However, buffer-local autocommands will not be executed for a buffer that has
been wiped out with :bwipe.  After deleting the buffer with :bdel the
buffer actually still exists (it becomes unlisted), thus the autocommands are
still executed.

7. Buffer-local autocommands    autocmd-buflocal autocmd-buffer-local
                                        <buffer=N> <buffer=abuf> E680

Buffer-local autocommands are attached to a specific buffer.  They are useful
if the buffer does not have a name and when the name does not match a specific
pattern.  But it also means they must be explicitly added to each buffer.

Instead of a pattern buffer-local autocommands use one of these forms:
        <buffer>        current buffer
        <buffer=99>     buffer number 99
        <buffer=abuf>   using <abuf> (only when executing autocommands)

    :au CursorHold <buffer>  echo 'hold'
    :au CursorHold <buffer=33>  echo 'hold'
    :au BufNewFile * au CursorHold <buffer=abuf>  echo 'hold'

All the commands for autocommands also work with buffer-local autocommands,
simply use the special string instead of the pattern.  Examples:
    :au! * <buffer>                  " remove buffer-local autocommands for
                                     " current buffer
    :au! * <buffer=33>               " remove buffer-local autocommands for
                                     " buffer #33
    :bufdo :au! CursorHold <buffer>  " remove autocmd for given event for all
                                     " buffers
    :au * <buffer>                   " list buffer-local autocommands for
                                     " current buffer

Note that when an autocommand is defined for the current buffer, it is stored
with the buffer number.  Thus it uses the form "<buffer=12>", where 12 is the
number of the current buffer.  You will see this when listing autocommands,
for example.

To test for presence of buffer-local autocommands use the exists() function
as follows:
    :if exists("#CursorHold#<buffer=12>") | ... | endif
    :if exists("#CursorHold#<buffer>") | ... | endif    " for current buffer

When a buffer is wiped out its buffer-local autocommands are also gone, of
course.  Note that when deleting a buffer, e.g., with ":bdel", it is only
unlisted, the autocommands are still present.  In order to see the removal of
buffer-local autocommands:
    :set verbose=6

It is not possible to define buffer-local autocommands for a non-existent

8. Groups                                               autocmd-groups

Autocommands can be put together in a group.  This is useful for removing or
executing a group of autocommands.  For example, all the autocommands for
syntax highlighting are put in the "highlight" group, to be able to execute
":doautoall highlight BufRead" when the GUI starts.

When no specific group is selected, Vim uses the default group.  The default
group does not have a name.  You cannot execute the autocommands from the
default group separately; you can execute them only by executing autocommands
for all groups.

Normally, when executing autocommands automatically, Vim uses the autocommands
for all groups.  The group only matters when executing autocommands with
":doautocmd" or ":doautoall", or when defining or deleting autocommands.

The group name can contain any characters except white space.  The group name
"end" is reserved (also in uppercase).

The group name is case sensitive.  Note that this is different from the event

                                                        :aug :augroup
:aug[roup] {name}               Define the autocmd group name for the
                                following ":autocmd" commands.  The name "end"
                                or "END" selects the default group.
                                To avoid confusion, the name should be
                                different from existing {event} names, as this
                                most likely will not do what you intended.

                                        :augroup-delete E367 W19 E936
:aug[roup]! {name}              Delete the autocmd group {name}.  Don't use
                                this if there is still an autocommand using
                                this group!  You will get a warning if doing
                                it anyway. when the group is the current group
                                you will get error E936.

To enter autocommands for a specific group, use this method:
1. Select the group with ":augroup {name}".
2. Delete any old autocommands with ":au!".
3. Define the autocommands.
4. Go back to the default group with "augroup END".

        :augroup uncompress
        :  au!
        :  au BufEnter *.gz     %!gunzip
        :augroup END

This prevents having the autocommands defined twice (e.g., after sourcing the
.vimrc file again).

9. Executing autocommands                               autocmd-execute

Vim can also execute Autocommands non-automatically.  This is useful if you
have changed autocommands, or when Vim has executed the wrong autocommands
(e.g., the file pattern match was wrong).

Note that the 'eventignore' option applies here too.  Events listed in this
option will not cause any commands to be executed.

                                        :do :doau :doautocmd E217
:do[autocmd] [<nomodeline>[group] {event} [fname]
                        Apply the autocommands matching [fname] (default:
                        current file name) for {event} to the current buffer.
                        You can use this when the current file name does not
                        match the right pattern, after changing settings, or
                        to execute autocommands for a certain event.
                        It's possible to use this inside an autocommand too,
                        so you can base the autocommands for one extension on
                        another extension.  Example:
                                :au BufEnter *.cpp so ~/.vimrc_cpp
                                :au BufEnter *.cpp doau BufEnter x.c
                        Be careful to avoid endless loops.  See

                        When the [group] argument is not given, Vim executes
                        the autocommands for all groups.  When the [group]
                        argument is included, Vim executes only the matching
                        autocommands for that group.  Note: if you use an
                        undefined group name, Vim gives you an error message.
                        After applying the autocommands the modelines are
                        processed, so that their settings overrule the
                        settings from autocommands, like what happens when
                        editing a file. This is skipped when the <nomodeline>
                        argument is present. You probably want to use
                        <nomodeline> for events that are not used when loading
                        a buffer, such as User.
                        Processing modelines is also skipped when no
                        matching autocommands were executed.

                                                :doautoa :doautoall
:doautoa[ll] [<nomodeline>[group] {event} [fname]
                        Like ":doautocmd", but apply the autocommands to each
                        loaded buffer.  Note that [fname] is used to select
                        the autocommands, not the buffers to which they are
                        Careful: Don't use this for autocommands that delete a
                        buffer, change to another buffer or change the
                        contents of a buffer; the result is unpredictable.
                        This command is intended for autocommands that set
                        options, change highlighting, and things like that.

10. Using autocommands                                  autocmd-use

For WRITING FILES there are four possible sets of events.  Vim uses only one
of these sets for a write command:

BufWriteCmd     BufWritePre     BufWritePost    writing the whole buffer
                FilterWritePre  FilterWritePost writing to filter temp file
FileAppendCmd   FileAppendPre   FileAppendPost  appending to a file
FileWriteCmd    FileWritePre    FileWritePost   any other file write

When there is a matching "*Cmd" autocommand, it is assumed it will do the
writing.  No further writing is done and the other events are not triggered.

Note that the *WritePost commands should undo any changes to the buffer that
were caused by the *WritePre commands; otherwise, writing the file will have
the side effect of changing the buffer.

Before executing the autocommands, the buffer from which the lines are to be
written temporarily becomes the current buffer.  Unless the autocommands
change the current buffer or delete the previously current buffer, the
previously current buffer is made the current buffer again.

The *WritePre and *AppendPre autocommands must not delete the buffer from
which the lines are to be written.

The '[ and '] marks have a special position:
- Before the *ReadPre event the '[ mark is set to the line just above where
  the new lines will be inserted.
- Before the *ReadPost event the '[ mark is set to the first line that was
  just read, the '] mark to the last line.
- Before executing the *WriteCmd, *WritePre and *AppendPre autocommands the '[
  mark is set to the first line that will be written, the '] mark to the last
Careful: '[ and '] change when using commands that change the buffer.

In commands which expect a file name, you can use "<afile>" for the file name
that is being read :<afile> (you can also use "%" for the current file
name).  "<abuf>" can be used for the buffer number of the currently effective
buffer.  This also works for buffers that doesn't have a name.  But it doesn't
work for files without a buffer (e.g., with ":r file").

Examples for reading and writing compressed files:
  :augroup gzip
  :  autocmd!
  :  autocmd BufReadPre,FileReadPre     *.gz set bin
  :  autocmd BufReadPost,FileReadPost   *.gz '[,']!gunzip
  :  autocmd BufReadPost,FileReadPost   *.gz set nobin
  :  autocmd BufReadPost,FileReadPost   *.gz execute ":doautocmd BufReadPost " . expand("%:r")
  :  autocmd BufWritePost,FileWritePost *.gz !mv <afile> <afile>:r
  :  autocmd BufWritePost,FileWritePost *.gz !gzip <afile>:r

  :  autocmd FileAppendPre              *.gz !gunzip <afile>
  :  autocmd FileAppendPre              *.gz !mv <afile>:r <afile>
  :  autocmd FileAppendPost             *.gz !mv <afile> <afile>:r
  :  autocmd FileAppendPost             *.gz !gzip <afile>:r
  :augroup END

The "gzip" group is used to be able to delete any existing autocommands with
":autocmd!", for when the file is sourced twice.

("<afile>:r" is the file name without the extension, see :_%:)

The commands executed for the BufNewFile, BufRead/BufReadPost, BufWritePost,
FileAppendPost and VimLeave events do not set or reset the changed flag of the
buffer.  When you decompress the buffer with the BufReadPost autocommands, you
can still exit with ":q".  When you use ":undo" in BufWritePost to undo the
changes made by BufWritePre commands, you can still do ":q" (this also makes
"ZZ" work).  If you do want the buffer to be marked as modified, set the
'modified' option.

To execute Normal mode commands from an autocommand, use the ":normal"
command.  Use with care!  If the Normal mode command is not finished, the user
needs to type characters (e.g., after ":normal m" you need to type a mark

If you want the buffer to be unmodified after changing it, reset the
'modified' option.  This makes it possible to exit the buffer with ":q"
instead of ":q!".

                                                        autocmd-nested E218
By default, autocommands do not nest.  If you use ":e" or ":w" in an
autocommand, Vim does not execute the BufRead and BufWrite autocommands for
those commands.  If you do want this, use the "nested" flag for those commands
in which you want nesting.  For example:
  :autocmd FileChangedShell *.c nested e!
The nesting is limited to 10 levels to get out of recursive loops.

It's possible to use the ":au" command in an autocommand.  This can be a
self-modifying command!  This can be useful for an autocommand that should
execute only once.

If you want to skip autocommands for one command, use the :noautocmd command
modifier or the 'eventignore' option.

Note: When reading a file (with ":read file" or with a filter command) and the
last line in the file does not have an <EOL>, Vim remembers this.  At the next
write (with ":write file" or with a filter command), if the same line is
written again as the last line in a file AND 'binary' is set, Vim does not
supply an <EOL>.  This makes a filter command on the just read lines write the
same file as was read, and makes a write command on just filtered lines write
the same file as was read from the filter.  For example, another way to write
a compressed file:

  :autocmd FileWritePre *.gz   set bin|'[,']!gzip
  :autocmd FileWritePost *.gz  undo|set nobin

You can specify multiple patterns, separated by commas.  Here are some

  :autocmd BufRead   *          set tw=79 nocin ic infercase fo=2croq
  :autocmd BufRead   .letter    set tw=72 fo=2tcrq
  :autocmd BufEnter  .letter    set dict=/usr/lib/dict/words
  :autocmd BufLeave  .letter    set dict=
  :autocmd BufRead,BufNewFile   *.c,*.h set tw=0 cin noic
  :autocmd BufEnter  *.c,*.h    abbr FOR for (i = 0; i < 3; ++i)<CR>{<CR>}<Esc>O
  :autocmd BufLeave  *.c,*.h    unabbr FOR

For makefiles (makefile, Makefile, imakefile, makefile.unix, etc.):

  :autocmd BufEnter  ?akefile*  set include=^s\=include
  :autocmd BufLeave  ?akefile*  set include&

To always start editing C files at the first function:

  :autocmd BufRead   *.c,*.h    1;/^{

Without the "1;" above, the search would start from wherever the file was
entered, rather than from the start of the file.

                                                skeleton template
To read a skeleton (template) file when opening a new file:

  :autocmd BufNewFile  *.c      0r ~/vim/skeleton.c
  :autocmd BufNewFile  *.h      0r ~/vim/skeleton.h
  :autocmd BufNewFile  *.java   0r ~/vim/

To insert the current date and time in a *.html file when writing it:

  :autocmd BufWritePre,FileWritePre *.html   ks|call LastMod()|'s
  :fun LastMod()
  :  if line("$") > 20
  :    let l = 20
  :  else
  :    let l = line("$")
  :  endif
  :  exe "1," . l . "g/Last modified: /s/Last modified: .*/Last modified: " .
  :  \ strftime("%Y %b %d")

You need to have a line "Last modified: <date time>" in the first 20 lines
of the file for this to work.  Vim replaces <date time> (and anything in the
same line after it) with the current date and time.  Explanation:
        ks              mark current position with mark 's'
        call LastMod()  call the LastMod() function to do the work
        's              return the cursor to the old position
The LastMod() function checks if the file is shorter than 20 lines, and then
uses the ":g" command to find lines that contain "Last modified: ".  For those
lines the ":s" command is executed to replace the existing date with the
current one.  The ":execute" command is used to be able to use an expression
for the ":g" and ":s" commands.  The date is obtained with the strftime()
function.  You can change its argument to get another date string.

When entering :autocmd on the command-line, completion of events and command
names may be done (with <Tab>CTRL-D, etc.) where appropriate.

Vim executes all matching autocommands in the order that you specify them.
It is recommended that your first autocommand be used for all files by using
"*" as the file pattern.  This means that you can define defaults you like
here for any settings, and if there is another matching autocommand it will
override these.  But if there is no other matching autocommand, then at least
your default settings are recovered (if entering this file from another for
which autocommands did match).  Note that "*" will also match files starting
with ".", unlike Unix shells.

Autocommands do not change the current search patterns.  Vim saves the current
search patterns before executing autocommands then restores them after the
autocommands finish.  This means that autocommands do not affect the strings
highlighted with the 'hlsearch' option.  Within autocommands, you can still
use search patterns normally, e.g., with the "n" command.
If you want an autocommand to set the search pattern, such that it is used
after the autocommand finishes, use the ":let @/ =" command.
The search-highlighting cannot be switched off with ":nohlsearch" in an
autocommand.  Use the 'h' flag in the 'viminfo' option to disable search-
highlighting when starting Vim.

When using one of the "*Cmd" events, the matching autocommands are expected to
do the file reading, writing or sourcing.  This can be used when working with
a special kind of file, for example on a remote system.
CAREFUL: If you use these events in a wrong way, it may have the effect of
making it impossible to read or write the matching files!  Make sure you test
your autocommands properly.  Best is to use a pattern that will never match a
normal file name, for example "ftp://*".

When defining a BufReadCmd it will be difficult for Vim to recover a crashed
editing session.  When recovering from the original file, Vim reads only those
parts of a file that are not found in the swap file.  Since that is not
possible with a BufReadCmd, use the :preserve command to make sure the
original file isn't needed for recovery.  You might want to do this only when
you expect the file to be modified.

For file read and write commands the v:cmdarg variable holds the "++enc="
and "++ff=" argument that are effective.  These should be used for the command
that reads/writes the file.  The v:cmdbang variable is one when "!" was
used, zero otherwise.

See the $VIMRUNTIME/plugin/netrwPlugin.vim for examples.

11. Disabling autocommands                              autocmd-disable

To disable autocommands for some time use the 'eventignore' option.  Note that
this may cause unexpected behavior, make sure you restore 'eventignore'
afterwards, using a :try block with :finally.

                                                        :noautocmd :noa
To disable autocommands for just one command use the ":noautocmd" command
modifier.  This will set 'eventignore' to "all" for the duration of the
following command.  Example:

        :noautocmd w fname.gz

This will write the file without triggering the autocommands defined by the
gzip plugin.