@c This is part of the Emacs manual.
-@c Copyright (C) 1985,86,87,93,94,95,97,99, 2000, 2001, 2004
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 1999, 2000,
+@c 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Files, Buffers, Keyboard Macros, Top
@chapter File Handling
* Quoted File Names:: Quoting special characters in file names.
* File Name Cache:: Completion against a list of files you often use.
* File Conveniences:: Convenience Features for Finding Files.
+* Filesets:: Handling sets of files.
@end menu
@node File Names
default directory is kept in the variable @code{default-directory},
which has a separate value in every buffer.
- For example, if the default file name is @file{/u/rms/gnu/gnu.tasks} then
-the default directory is @file{/u/rms/gnu/}. If you type just @samp{foo},
-which does not specify a directory, it is short for @file{/u/rms/gnu/foo}.
-@samp{../.login} would stand for @file{/u/rms/.login}. @samp{new/foo}
-would stand for the file name @file{/u/rms/gnu/new/foo}.
-
@findex cd
@findex pwd
The command @kbd{M-x pwd} displays the current buffer's default
directory, and the command @kbd{M-x cd} sets it (to a value read using
the minibuffer). A buffer's default directory changes only when the
@code{cd} command is used. A file-visiting buffer's default directory
-is initialized to the directory of the file that is visited in that buffer. If
-you create a buffer with @kbd{C-x b}, its default directory is copied
-from that of the buffer that was current at the time.
+is initialized to the directory of the file it visits. If you create
+a buffer with @kbd{C-x b}, its default directory is copied from that
+of the buffer that was current at the time.
+
+ For example, if the default file name is @file{/u/rms/gnu/gnu.tasks}
+then the default directory is normally @file{/u/rms/gnu/}. If you
+type just @samp{foo}, which does not specify a directory, it is short
+for @file{/u/rms/gnu/foo}. @samp{../.login} would stand for
+@file{/u/rms/.login}. @samp{new/foo} would stand for the file name
+@file{/u/rms/gnu/new/foo}.
@vindex insert-default-directory
The default directory actually appears in the minibuffer when the
first slash in the double slash; the result is @samp{/x1/rms/foo}.
@xref{Minibuffer File}.
+@cindex home directory shorthand
+ You can use @file{~/} in a file name to mean your home directory,
+or @file{~@var{user-id}/} to mean the home directory of a user whose
+login name is @code{user-id}. (On DOS and Windows systems, where a user
+doesn't have a home directory, Emacs substitutes @file{~/} with the
+value of the environment variable @code{HOME}; see @ref{General
+Variables}.)
+
@cindex environment variables in file names
@cindex expansion of environment variables
@cindex @code{$} in file names
Note that shell commands to set environment variables affect Emacs
only when done before Emacs is started.
-@cindex home directory shorthand
- You can use @file{~/} in a file name to mean your home directory,
-or @file{~@var{user-id}/} to mean the home directory of a user whose
-login name is @code{user-id}. (On DOS and Windows systems, where a user
-doesn't have a home directory, Emacs substitutes @file{~/} with the
-value of the environment variable @code{HOME}; see @ref{General
-Variables}.)
-
To access a file with @samp{$} in its name, if the @samp{$} causes
expansion, type @samp{$$}. This pair is converted to a single
@samp{$} at the same time as variable substitution is performed for a
literal @samp{~} should also be quoted with @samp{/:}.
@findex substitute-in-file-name
- The Lisp function that performs the substitution is called
+ The Lisp function that performs the @samp{$}-substitution is called
@code{substitute-in-file-name}. The substitution is performed only on
file names read as such using the minibuffer.
You can include non-@acronym{ASCII} characters in file names if you set the
variable @code{file-name-coding-system} to a non-@code{nil} value.
-@xref{Specify Coding}.
+@xref{File Name Coding}.
@node Visiting
@section Visiting Files
The changes you make with editing commands are made in the Emacs
buffer. They do not take effect in the file that you visited, or any
-place permanent, until you @dfn{save} the buffer. Saving the buffer
+permanent place, until you @dfn{save} the buffer. Saving the buffer
means that Emacs writes the current contents of the buffer into its
visited file. @xref{Saving}.
@kbd{C-g}. File-name completion ignores certain filenames; for more
about this, see @ref{Completion Options}.
- Your confirmation that @kbd{C-x C-f} has completed successfully is the
-appearance of new text on the screen and a new buffer name in the mode
-line. If the specified file does not exist and could not be created, or
-cannot be read, then you get an error, with an error message displayed
-in the echo area.
+ Your confirmation that @kbd{C-x C-f} has completed successfully is
+the appearance of new text on the screen and a new buffer name in the
+mode line. If the specified file does not exist and you could not
+create it, or exists but you can't read it, then you get an error,
+with an error message displayed in the echo area.
If you visit a file that is already in Emacs, @kbd{C-x C-f} does not make
another copy. It selects the existing buffer containing that file.
-However, before doing so, it checks that the file itself has not changed
-since you visited or saved it last. If the file has changed, a warning
-message is shown. @xref{Interlocking,,Simultaneous Editing}.
+However, before doing so, it checks whether the file itself has changed
+since you visited or saved it last. If the file has changed, Emacs offers
+to reread it.
@vindex large-file-warning-threshold
@cindex maximum buffer size exceeded, error message
saying that the maximum buffer size has been exceeded.
@cindex file selection dialog
- On graphical terminals, there are two additional methods for
+ On graphical displays there are two additional methods for
visiting files. Firstly, when Emacs is built with a suitable GUI
toolkit, commands invoked with the mouse (by clicking on the menu bar
or tool bar) use the toolkit's standard File Selection dialog instead
of prompting for the file name in the minibuffer. On Unix and
GNU/Linux platforms, Emacs does that when built with GTK, LessTif, and
-Motif toolkits; on MS-Windows, the GUI version does that by default.
-For information on how to customize this, see @xref{Dialog Boxes}.
+Motif toolkits; on MS-Windows and Mac, the GUI version does that by default.
+For information on how to customize this, see @ref{Dialog Boxes}.
- Secondly, Emacs supports the ``drag and drop'' protocol on the X
-window system. Dropping a file into an ordinary Emacs window visits
-the file using that window. However, dropping a file into a window
-displaying a Dired buffer moves or copies the file into the displayed
-directory. For details, see @ref{Drag and Drop}, @ref{Misc Dired
-Features}.
+ Secondly, Emacs supports ``drag and drop''; dropping a file into an
+ordinary Emacs window visits the file using that window. However,
+dropping a file into a window displaying a Dired buffer moves or
+copies the file into the displayed directory. For details, see
+@ref{Drag and Drop}, and @ref{Misc Dired Features}.
@cindex creating files
What if you want to create a new file? Just visit it. Emacs displays
@cindex wildcard characters in file names
@vindex find-file-wildcards
- If the file name you specify contains shell-style wildcard characters,
-Emacs visits all the files that match it. Wildcards include @samp{?},
-@samp{*}, and @samp{[@dots{}]} sequences. @xref{Quoted File Names}, for
-information on how to visit a file whose name actually contains wildcard
-characters. You can disable the wildcard feature by customizing
+ If the file name you specify contains shell-style wildcard
+characters, Emacs visits all the files that match it. Wildcards
+include @samp{?}, @samp{*}, and @samp{[@dots{}]} sequences. To enter
+the wild card @samp{?} in a file name in the minibuffer, you need to
+type @kbd{C-q ?}. @xref{Quoted File Names}, for information on how to
+visit a file whose name actually contains wildcard characters. You
+can disable the wildcard feature by customizing
@code{find-file-wildcards}.
If you visit a file that the operating system won't let you modify,
default file name in the buffer, with point just after the directory
part; this is convenient if you made a slight error in typing the name.
- If you find a file which exists but cannot be read, @kbd{C-x C-f}
-signals an error.
-
@kindex C-x 4 f
@findex find-file-other-window
@kbd{C-x 4 f} (@code{find-file-other-window}) is like @kbd{C-x C-f}
@dfn{Saving} a buffer in Emacs means writing its contents back into the file
that was visited in the buffer.
+@menu
+* Save Commands:: Commands for saving files.
+* Backup:: How Emacs saves the old version of your file.
+* Customize Save:: Customizing the saving of files.
+* Interlocking:: How Emacs protects against simultaneous editing
+ of one file by two users.
+* Shadowing: File Shadowing. Copying files to "shadows" automatically.
+* Time Stamps:: Emacs can update time stamps on saved files.
+@end menu
+
+@node Save Commands
+@subsection Commands for Saving Files
+
+ These are the commands that relate to saving and writing files.
+
@table @kbd
@item C-x C-s
Save the current buffer in its visited file on disk (@code{save-buffer}).
Forget that the current buffer has been changed (@code{not-modified}).
With prefix argument (@kbd{C-u}), mark the current buffer as changed.
@item C-x C-w
-Save the current buffer as a specified file name (@code{write-file}).
+Save the current buffer with a specified file name (@code{write-file}).
@item M-x set-visited-file-name
Change the file name under which the current buffer will be saved.
@end table
a different file name, one which is not in use for anything important.
Alternatively, you can cancel all the changes made since the file was
visited or saved, by reading the text from the file again. This is
-called @dfn{reverting}. @xref{Reverting}. You could also undo all the
+called @dfn{reverting}. @xref{Reverting}. (You could also undo all the
changes by repeating the undo command @kbd{C-x u} until you have undone
-all the changes; but reverting is easier.
+all the changes; but reverting is easier.) You can also kill the buffer.
@findex set-visited-file-name
@kbd{M-x set-visited-file-name} alters the name of the file that the
@kindex C-x C-w
@findex write-file
If you wish to mark the buffer as visiting a different file and save it
-right away, use @kbd{C-x C-w} (@code{write-file}). It is precisely
-equivalent to @code{set-visited-file-name} followed by @kbd{C-x C-s}.
+right away, use @kbd{C-x C-w} (@code{write-file}). It is
+equivalent to @code{set-visited-file-name} followed by @kbd{C-x C-s}
+(except that @kbd{C-x C-w} asks for confirmation if the file exists).
@kbd{C-x C-s} used on a buffer that is not visiting a file has the
same effect as @kbd{C-x C-w}; that is, it reads a file name, marks the
buffer as visiting that file, and saves it there. The default file name in
by simultaneous editing and requires your immediate attention.
@xref{Interlocking,, Simultaneous Editing}.
-@vindex require-final-newline
- If the value of the variable @code{require-final-newline} is
-@code{t}, Emacs silently puts a newline at the end of any file that
-doesn't already end in one, every time a file is saved or written. If
-the value is @code{visit}, Emacs adds a newline at the end of any file
-that doesn't have one, just after it visits the file. (This marks the
-buffer as modified, and you can undo it.) If the value is
-@code{visit-save}, that means to add newlines both on visiting and on
-saving. If the value is @code{nil}, Emacs leaves the end of the file
-unchanged; if it's neither @code{nil} nor @code{t}, Emacs asks you
-whether to add a newline. The default is @code{nil}.
-
-@vindex mode-require-final-newline
- Many major modes are designed for specific kinds of files that are
-always supposed to end in newlines. These major modes set the
-variable @code{require-final-newline} according to
-@code{mode-require-final-newline}. By setting the latter variable,
-you can control how these modes handle final newlines.
-
-@menu
-* Backup:: How Emacs saves the old version of your file.
-* Interlocking:: How Emacs protects against simultaneous editing
- of one file by two users.
-* Shadowing: File Shadowing.
- Copying files to "shadows" automatically.
-* Time Stamps:: Emacs can update time stamps on saved files.
-@end menu
-
@node Backup
@subsection Backup Files
@cindex backup file
are redundant when you store all the previous versions in a version
control system. @xref{General VC Options}.
+ At your option, Emacs can keep either a single backup for each file,
+or make a series of numbered backup files for each file that you edit.
+
@vindex backup-enable-predicate
@vindex temporary-file-directory
@vindex small-temporary-file-directory
for temporary files, specified by @code{temporary-file-directory} or
@code{small-temporary-file-directory}.
- At your option, Emacs can keep either a single backup file or a series of
-numbered backup files for each file that you edit.
-
Emacs makes a backup for a file only the first time the file is saved
from one buffer. No matter how many times you save a file, its backup file
continues to contain the contents from before the file was visited.
newly saved contents if you save again.
@menu
-* Names: Backup Names. How backup files are named;
- choosing single or numbered backup files.
+* One or Many: Numbered Backups. Whether to make one backup file or many.
+* Names: Backup Names. How backup files are named.
* Deletion: Backup Deletion. Emacs deletes excess numbered backups.
* Copying: Backup Copying. Backups can be made by copying or renaming.
@end menu
+@node Numbered Backups
+@subsubsection Numbered Backups
+
+@vindex version-control
+ The choice of single backup file or multiple numbered backup files
+is controlled by the variable @code{version-control}. Its possible
+values are:
+
+@table @code
+@item t
+Make numbered backups.
+@item nil
+Make numbered backups for files that have numbered backups already.
+Otherwise, make single backups.
+@item never
+Never make numbered backups; always make single backups.
+@end table
+
+@noindent
+The usual way to set this variable is globally, through your
+@file{.emacs} file or the customization buffer. However, you can set
+@code{version-control} locally in an individual buffer to control the
+making of backups for that buffer's file. For example, Rmail mode
+locally sets @code{version-control} to @code{never} to make sure that
+there is only one backup for an Rmail file. @xref{Locals}.
+
+@cindex @env{VERSION_CONTROL} environment variable
+ If you set the environment variable @env{VERSION_CONTROL}, to tell
+various GNU utilities what to do with backup files, Emacs also obeys the
+environment variable by setting the Lisp variable @code{version-control}
+accordingly at startup. If the environment variable's value is @samp{t}
+or @samp{numbered}, then @code{version-control} becomes @code{t}; if the
+value is @samp{nil} or @samp{existing}, then @code{version-control}
+becomes @code{nil}; if it is @samp{never} or @samp{simple}, then
+@code{version-control} becomes @code{never}.
+
@node Backup Names
@subsubsection Single or Numbered Backups
- If you choose to have a single backup file (this is the default),
-the backup file's name is normally constructed by appending @samp{~} to the
-file name being edited; thus, the backup file for @file{eval.c} would
-be @file{eval.c~}.
+ When Emacs makes a single backup file, its name is normally
+constructed by appending @samp{~} to the file name being edited; thus,
+the backup file for @file{eval.c} would be @file{eval.c~}.
@vindex make-backup-file-name-function
@vindex backup-directory-alist
@code{backup-directory-alist} applies to numbered backups just as
usual.
-@vindex version-control
- The choice of single backup or numbered backups is controlled by the
-variable @code{version-control}. Its possible values are
-
-@table @code
-@item t
-Make numbered backups.
-@item nil
-Make numbered backups for files that have numbered backups already.
-Otherwise, make single backups.
-@item never
-Never make numbered backups; always make single backups.
-@end table
-
-@noindent
-You can set @code{version-control} locally in an individual buffer to
-control the making of backups for that buffer's file. For example,
-Rmail mode locally sets @code{version-control} to @code{never} to make sure
-that there is only one backup for an Rmail file. @xref{Locals}.
-
-@cindex @env{VERSION_CONTROL} environment variable
- If you set the environment variable @env{VERSION_CONTROL}, to tell
-various GNU utilities what to do with backup files, Emacs also obeys the
-environment variable by setting the Lisp variable @code{version-control}
-accordingly at startup. If the environment variable's value is @samp{t}
-or @samp{numbered}, then @code{version-control} becomes @code{t}; if the
-value is @samp{nil} or @samp{existing}, then @code{version-control}
-becomes @code{nil}; if it is @samp{never} or @samp{simple}, then
-@code{version-control} becomes @code{never}.
-
@node Backup Deletion
@subsubsection Automatic Deletion of Backups
any alternate names for the same file. This has nothing to do with
Emacs---the version control system does it.
+@node Customize Save
+@subsection Customizing Saving of Files
+
+@vindex require-final-newline
+ If the value of the variable @code{require-final-newline} is
+@code{t}, saving or writing a file silently puts a newline at the end
+if there isn't already one there. If the value is @code{visit}, Emacs
+adds a newline at the end of any file that doesn't have one, just
+after it visits the file. (This marks the buffer as modified, and you
+can undo it.) If the value is @code{visit-save}, that means to add
+newlines both on visiting and on saving. If the value is @code{nil},
+Emacs leaves the end of the file unchanged; if it's neither @code{nil}
+nor @code{t}, Emacs asks you whether to add a newline. The default is
+@code{nil}.
+
+@vindex mode-require-final-newline
+ Many major modes are designed for specific kinds of files that are
+always supposed to end in newlines. These major modes set the
+variable @code{require-final-newline} according to
+@code{mode-require-final-newline}. By setting the latter variable,
+you can control how these modes handle final newlines.
+
+@vindex write-region-inhibit-fsync
+ When Emacs saves a file, it invokes the @code{fsync} system call to
+force the data immediately out to disk. This is important for safety
+if the system crashes or in case of power outage. However, it can be
+disruptive on laptops using power saving, because it requires the disk
+to spin up each time you save a file. Setting
+@code{write-region-inhibit-fsync} to a non-@code{nil} value disables
+this synchronization. Be careful---this means increased risk of data
+loss.
+
@node Interlocking
@subsection Protection against Simultaneous Editing
@subsection Shadowing Files
@cindex shadow files
@cindex file shadows
+@findex shadow-initialize
@table @kbd
@item M-x shadow-initialize
@node Time Stamps
@subsection Updating Time Stamps Automatically
-@findex time-stamp
@cindex time stamps
@cindex modification dates
@cindex locale, date format
Time-stamp: " "
@end example
+@findex time-stamp
Then add the hook function @code{time-stamp} to the hook
@code{before-save-hook}; that hook function will automatically update
the time stamp, inserting the current date and time when you save the
You may find it useful to have Emacs revert files automatically when
they change. Three minor modes are available to do this.
- @kbd{M-x global-auto-revert-mode} runs Global Auto-Revert mode,
+ @kbd{M-x global-auto-revert-mode} enables Global Auto-Revert mode,
which periodically checks all file buffers and reverts when the
-corresponding file has changed. @kbd{M-x auto-revert-mode} runs a
-local version, Auto-Revert mode, which applies only to the buffer in
-which it was activated. Auto-Revert mode can be used to ``tail'' a
-file, such as a system log, so that changes made to that file by other
-programs are continuously displayed. To do this, just move the point
-to the end of the buffer, and it will stay there as the file contents
-change. However, if you are sure that the file will only change by
-growing at the end, you can tail the file more efficiently using
-Auto-Revert Tail mode, @kbd{M-x auto-revert-tail-mode}.
+corresponding file has changed. @kbd{M-x auto-revert-mode} enables a
+local version, Auto-Revert mode, which applies only to the current
+buffer.
+
+ You can use Auto-Revert mode to ``tail'' a file such as a system
+log, so that changes made to that file by other programs are
+continuously displayed. To do this, just move the point to the end of
+the buffer, and it will stay there as the file contents change.
+However, if you are sure that the file will only change by growing at
+the end, use Auto-Revert Tail mode instead
+(@code{auto-revert-tail-mode}). It is more efficient for this.
@vindex auto-revert-interval
The variable @code{auto-revert-interval} controls how often to check
for a changed file. Since checking a remote file is too slow, these
modes do not check or revert remote files.
-@vindex auto-revert-check-vc-info
- Whenever Auto Revert mode reverts the buffer, it updates the version
-control information, such as the version control number displayed in
-the mode line. However, this information may not be properly updated
-if the version control state changes outside of Emacs---for example,
-if a new version is checked in from outside the current Emacs session.
-If you set @code{auto-revert-check-vc-info} to @code{t}, Auto Revert
-mode will update the version control status information periodically.
+ @xref{VC Mode Line}, for Auto Revert peculiarities in buffers that
+visit files under version control.
@node Auto Save
@section Auto-Saving: Protection Against Disasters
It prevents you from losing more than a limited amount of work if the
system crashes.
- When Emacs determines that it is time for auto-saving, each buffer is
-considered, and is auto-saved if auto-saving is turned on for it and it
-has been changed since the last time it was auto-saved. The message
-@samp{Auto-saving...} is displayed in the echo area during auto-saving,
-if any files are actually auto-saved. Errors occurring during
-auto-saving are caught so that they do not interfere with the execution
-of commands you have been typing.
+ When Emacs determines that it is time for auto-saving, it considers
+each buffer, and each is auto-saved if auto-saving is enabled for it
+and it has been changed since the last time it was auto-saved. The
+message @samp{Auto-saving...} is displayed in the echo area during
+auto-saving, if any files are actually auto-saved. Errors occurring
+during auto-saving are caught so that they do not interfere with the
+execution of commands you have been typing.
@menu
* Files: Auto Save Files. The file where auto-saved changes are
@vindex delete-auto-save-files
A buffer's auto-save file is deleted when you save the buffer in its
-visited file. To inhibit this, set the variable @code{delete-auto-save-files}
-to @code{nil}. Changing the visited file name with @kbd{C-x C-w} or
-@code{set-visited-file-name} renames any auto-save file to go with
-the new visited name.
+visited file. (You can inhibit this by setting the variable
+@code{delete-auto-save-files} to @code{nil}.) Changing the visited
+file name with @kbd{C-x C-w} or @code{set-visited-file-name} renames
+any auto-save file to go with the new visited name.
@node Auto Save Control
@subsection Controlling Auto-Saving
@file{foo} is just an alias. More complex cases occur when symbolic
links point to directories.
- If you visit two names for the same file, normally Emacs makes
-two different buffers, but it warns you about the situation.
-
@vindex find-file-existing-other-name
@vindex find-file-suppress-same-file-warnings
+
Normally, if you visit a file which Emacs is already visiting under
a different name, Emacs displays a message in the echo area and uses
the existing buffer visiting that file. This can happen on systems
-that support symbolic links, or if you use a long file name on a
-system that truncates long file names. You can suppress the message by
-setting the variable @code{find-file-suppress-same-file-warnings} to a
-non-@code{nil} value. You can disable this feature entirely by setting
-the variable @code{find-file-existing-other-name} to @code{nil}: then
-if you visit the same file under two different names, you get a separate
-buffer for each file name.
+that support hard or symbolic links, or if you use a long file name on
+a system that truncates long file names, or on a case-insensitive file
+system. You can suppress the message by setting the variable
+@code{find-file-suppress-same-file-warnings} to a non-@code{nil}
+value. You can disable this feature entirely by setting the variable
+@code{find-file-existing-other-name} to @code{nil}: then if you visit
+the same file under two different names, you get a separate buffer for
+each file name.
@vindex find-file-visit-truename
@cindex truenames of files
terms of capabilities, it is the weakest of the six that VC supports.
VC compensates for certain features missing in SCCS (snapshots, for
example) by implementing them itself, but some other VC features, such
-as multiple branches, are not available with SCCS. You should use
-SCCS only if for some reason you cannot use RCS, or one of the
-higher-level systems such as CVS or GNU Arch.
+as multiple branches, are not available with SCCS. Since SCCS is
+non-free, not respecting its users freedom,d, you should not use it;
+use its free replacement CSSC instead. But you should use CSSC only
+if for some reason you cannot use RCS, or one of the higher-level
+systems such as CVS or GNU Arch.
+
+In the following, we discuss mainly RCS, SCCS and CVS. Nearly
+everything said about CVS applies to GNU Arch, Subversion and Meta-CVS
+as well.
@node VC Concepts
@subsubsection Concepts of Version Control
that it is modified. If the file is locked by some other user (for
instance, @samp{jim}), that is displayed as @samp{RCS:jim:1.3}.
+@vindex auto-revert-check-vc-info
+ When Auto Revert mode (@pxref{Reverting}) reverts a buffer that is
+under version control, it updates the version control information in
+the mode line. However, Auto Revert mode may not properly update this
+information if the version control status changes without changes to
+the work file, from outside the current Emacs session. If you set
+@code{auto-revert-check-vc-info} to @code{t}, Auto Revert mode updates
+the version control status information every
+@code{auto-revert-interval} seconds, even if the work file itself is
+unchanged. The resulting CPU usage depends on the version control
+system, but is usually not excessive.
+
@node Basic VC Editing
@subsection Basic Editing under Version Control
since you began editing it, and when this happens, his changes will be
effectively removed when you check in your version (though they will
remain in the master file, so they will not be entirely lost). You must
-therefore verify the current version is unchanged, before you check in your
-changes. We hope to eliminate this risk and provide automatic merging
-with RCS in a future Emacs version.
+therefore verify that the current version is unchanged, before you
+check in your changes. We hope to eliminate this risk and provide
+automatic merging with RCS in a future Emacs version.
In addition, locking is possible with RCS even in this mode, although
it is not required; @kbd{C-x v v} with an unmodified file locks the
When you check in changes, @kbd{C-x v v} first reads a log entry. It
pops up a buffer called @samp{*VC-Log*} for you to enter the log entry.
-When you are finished, type @kbd{C-c C-c} in the @samp{*VC-Log*} buffer.
-That is when check-in really happens.
+
+ Sometimes the @samp{*VC-Log*} buffer contains default text when you enter it,
+typically the last log message entered. If it does, mark and point
+are set around the entire contents of the buffer so that it is easy to
+kill the contents of the buffer with @kbd{C-w}.
+
+@findex log-edit-insert-changelog
+ If you work by writing entries in the @file{ChangeLog}
+(@pxref{Change Log}) and then commit the change under revision
+control, you can generate the Log Edit text from the ChangeLog using
+@kbd{C-c C-a} (@kbd{log-edit-insert-changelog}). This looks for
+entries for the file(s) concerned in the top entry in the ChangeLog
+and uses those paragraphs as the log text. This text is only inserted
+if the top entry was made under your user name on the current date.
+@xref{Change Logs and VC}, for the opposite way of
+working---generating ChangeLog entries from the revision control log.
+
+ In the @samp{*VC-Log*} buffer, @kbd{C-c C-f} (@kbd{M-x log-edit-show-files})
+shows the list of files to be committed in case you need to check
+that. (This can be a list of more than one file if you use VC Dired
+mode or PCL-CVS. @xref{VC Dired Mode}, and @ref{Top, , About PCL-CVS,
+pcl-cvs, PCL-CVS --- The Emacs Front-End to CVS}.)
+
+ When you have finished editing the log message, type @kbd{C-c C-c} to
+exit the buffer and commit the change.
To abort check-in, just @strong{don't} type @kbd{C-c C-c} in that
buffer. You can switch buffers and do other editing. As long as you
@kindex C-x v g
For some backends, you can display the file @dfn{annotated} with
per-line version information and using colors to enhance the visual
-appearance, with the the command @kbd{M-x vc-annotate}.
-It creates a new buffer
-to display file's text, colored to show how old each part is. Text
+appearance, with the command @kbd{M-x vc-annotate}.
+It creates a new buffer (the ``annotate buffer'') displaying the
+file's text, with each part colored to show how old it is. Text
colored red is new, blue means old, and intermediate colors indicate
intermediate ages. By default, the time scale is 360 days, so that
everything more than one year old is shown in blue.
stretch factor greater than 1 means the color range spans more than a
year.
-From the annotate buffer, you can use the following keys to browse the
+ From the annotate buffer, you can use the following keys to browse the
annotations of past revisions, view diffs, or view log entries:
-@itemize @bullet
-
-@item
-Pressing @kbd{P} annotates the previous revision. It also takes a
-numeric prefix argument, so for example @kbd{C-u 10 P} would take you
-back 10 revisions.
-
-@item
-Pressing @kbd{N} annotates the next revision. It also takes a numeric
-prefix argument, so for example @kbd{C-u 10 N} would take you forward
-10 revisions.
-
-@item
-Pressing @kbd{J} annotates the revision at line (as denoted by the
-version number on the same line).
-
-@item
-Pressing @kbd{A} annotates the revision previous to line (as denoted
-by the version number on the same line). This is useful to see the
-state the file was in before the change on the current line was made.
-
-@item
-Pressing @kbd{D} shows the diff of the revision at line with its
-previous revision. This is useful to see what actually changed when
-the revision denoted on the current line was committed.
-
-@item
-Pressing @kbd{L} shows the log of the revision at line. This is
-useful to see the author's description of the changes that occurred
-when the revision denoted on the current line was committed.
-
-@item
-Pressing @kbd{W} annotates the workfile (most up to date) version. If
-you used @kbd{P} and @kbd{N} to browse to other revisions, use this
-key to return to the latest version.
-@end itemize
+@table @kbd
+@item P
+Annotate the previous revision, that is to say, the revision before
+the one currently annotated. A numeric prefix argument is a repeat
+count, so @kbd{C-u 10 P} would take you back 10 revisions.
+
+@item N
+Annotate the next revision---the one after the revision currently
+annotated. A numeric prefix argument is a repeat count.
+
+@item J
+Annotate the revision indicated by the current line.
+
+@item A
+Annotate the revision before the one indicated by the current line.
+This is useful to see the state the file was in before the change on
+the current line was made.
+
+@item D
+Display the diff between the current line's revision and the previous
+revision. This is useful to see what the current line's revision
+actually changed in the file.
+
+@item L
+Show the log of the current line's revision. This is useful to see
+the author's description of the changes in the revision on the current
+line.
+
+@item W
+Annotate the workfile version--the one you are editing. If you used
+@kbd{P} and @kbd{N} to browse to other revisions, use this key to
+return to the latest version.
+@end table
@node Secondary VC Commands
@subsection The Secondary Commands of VC
that appears first in @code{vc-handled-backends} (@pxref{Customizing VC}).
On the other hand, if there are no files already registered,
Emacs uses the first system from @code{vc-handled-backends} that could
-register the file---for example, you cannot register a file under CVS if
-its directory is not already part of a CVS tree.
-
- With the default value of @code{vc-handled-backends}, this means
-that Emacs uses RCS if there are any files under RCS control, CVS if
-there are any files under CVS, SCCS if any files are under SCCS, or
-RCS as the ultimate default.
+register the file (for example, you cannot register a file under CVS if
+its directory is not already part of a CVS tree); with the default
+value of @code{vc-handled-backends}, this means that Emacs uses RCS in
+this situation.
If locking is in use, @kbd{C-x v i} leaves the file unlocked and
read-only. Type @kbd{C-x v v} if you wish to start editing it. After
registering a file with CVS, you must subsequently commit the initial
-version by typing @kbd{C-x v v}.
+version by typing @kbd{C-x v v}. Until you do that, the version
+appears as @samp{@@@@} in the mode line.
@vindex vc-default-init-version
@cindex initial version number to register
To view the detailed version control status and history of a file,
type @kbd{C-x v l} (@code{vc-print-log}). It displays the history of
changes to the current file, including the text of the log entries. The
-output appears in a separate window.
+output appears in a separate window. The point is centered at the
+revision of the file that is currently being visited.
+
+ In the change log buffer, you can use the following keys to move
+between the logs of revisions and of files, to view past revisions, and
+to view diffs:
+
+@table @kbd
+@item p
+Move to the previous revision-item in the buffer. (Revision entries in the log
+buffer are usually in reverse-chronological order, so the previous
+revision-item usually corresponds to a newer revision.) A numeric
+prefix argument is a repeat count.
+
+@item n
+Move to the next revision-item (which most often corresponds to the
+previous revision of the file). A numeric prefix argument is a repeat
+count.
+
+@item P
+Move to the log of the previous file, when the logs of multiple files
+are in the log buffer (@pxref{VC Dired Mode}). Otherwise, just move
+to the beginning of the log. A numeric prefix argument is a repeat
+count, so @kbd{C-u 10 P} would move backward 10 files.
+
+@item N
+Move to the log of the next file, when the logs of multiple files are
+in the log buffer (@pxref{VC Dired Mode}). It also takes a numeric
+prefix argument as a repeat count.
+
+@item f
+Visit the revision indicated at the current line, like typing @kbd{C-x
+v ~} and specifying this revision's number (@pxref{Old Versions}).
+
+@item d
+Display the diff (@pxref{Comparing Files}) between the revision
+indicated at the current line and the next earlier revision. This is
+useful to see what actually changed when the revision indicated on the
+current line was committed.
+@end table
@node VC Undo
@subsubsection Undoing Version Control Actions
If it operates on more than one file, it handles each file according to
its current state; thus, it might lock one file, but check in another
file. This could be confusing; it is up to you to avoid confusing
-behavior by marking a set of files that are in a similar state.
+behavior by marking a set of files that are in a similar state. If no
+files are marked, @kbd{v v} operates on the file in the current line.
If any files call for check-in, @kbd{v v} reads a single log entry,
then uses it for all the files being checked in. This is convenient for
features. Each such independent line of development is called a
@dfn{branch}. VC allows you to create branches, switch between
different branches, and merge changes from one branch to another.
-Please note, however, that branches are only supported for RCS at the
-moment.
+Please note, however, that branches are not supported for SCCS.
A file's main line of development is usually called the @dfn{trunk}.
The versions on the trunk are normally numbered 1.1, 1.2, 1.3, etc. At
correspond to those of CVS. Technically, this is not a problem, but
it can become difficult to keep track of what is in the CVS repository
and what is not. So we suggest that you return from time to time to
-CVS-only operation, using @kbd{C-u C-x v v cvs @key{RET}}.
+CVS-only operation, by committing your local changes back to the
+repository using @kbd{C-u C-x v v cvs @key{RET}}.
@node Snapshots
@subsection Snapshots
@cindex named configurations (RCS)
VC's snapshot facilities are modeled on RCS's named-configuration
-support. They use RCS's native facilities for this, so under VC
-snapshots made using RCS are visible even when you bypass VC.
+support. They use RCS's native facilities for this, so
+snapshots made using RCS through VC are visible even when you bypass VC.
@c worded verbosely to avoid overfull hbox.
For SCCS, VC implements snapshots itself. The files it uses contain
name/file/version-number triples. These snapshots are visible only
through VC.
+@c ??? What about CVS?
+
A snapshot is a set of checked-in versions. So make sure that all the
files are checked in and not locked when you make a snapshot.
This command works with RCS or CVS only, not with SCCS.
+@c ??? What about other back ends?
+
@item C-u C-x v a
As above, but only find entries for the current buffer's file.
snapshot thus modified may not completely work (@pxref{Snapshot
Caveats}).
+ Some backends do not provide an explicit rename operation to their
+repositories. After issuing @code{vc-rename-file}, use @kbd{C-x v v}
+on the original and renamed buffers and provide the necessary edit
+log.
+
You cannot use @code{vc-rename-file} on a file that is locked by
someone else.
@dfn{version headers} are replaced in each successive version by the
number of that version.
+@c ??? How does this relate to CVS?
+
If you are using RCS, and version headers are present in your working
files, Emacs can use them to determine the current version and the
locking state of the files. This is more reliable than referring to the
Insert headers in a file for use with your version-control system.
@end table
-@vindex vc-header-alist
+@vindex vc-@var{backend}-header
The default header string is @samp{@w{$}Id$} for RCS and
@samp{@w{%}W%} for SCCS. You can specify other headers to insert by
-setting the variable @code{vc-header-alist}. Its value is a list of
-elements of the form @code{(@var{program} . @var{string})} where
-@var{program} is @code{RCS} or @code{SCCS} and @var{string} is the
-string to use.
+setting the variables @code{vc-@var{backend}-header} where
+@var{backend} is @code{rcs} or @code{sccs}.
Instead of a single string, you can specify a list of strings; then
each string in the list is inserted as a separate header on a line of
its own.
- It is often necessary to use ``superfluous'' backslashes when
+ It may be necessary to use apparently-superfluous backslashes when
writing the strings that you put in this variable. For instance, you
might write @code{"$Id\$"} rather than @code{"$Id@w{$}"}. The extra
backslash prevents the string constant from being interpreted as a
@var{regexp} matches the buffer name, @var{format} is inserted as part
of the header. A header line is inserted for each element that matches
the buffer name, and for each string specified by
-@code{vc-header-alist}. The header line is made by processing the
-string from @code{vc-header-alist} with the format taken from the
+@code{vc-@var{backend}-header}. The header line is made by processing the
+string from @code{vc-@var{backend}-header} with the format taken from the
element. The default value for @code{vc-static-header-alist} is as follows:
@example
@vindex vc-handled-backends
The variable @code{vc-handled-backends} determines which version
control systems VC should handle. The default value is @code{(RCS CVS
-SCCS)}, so it contains all three version systems that are currently
-supported. If you want VC to ignore one or more of these systems,
-exclude its name from the list. To disable VC entirely, set this
-variable to @code{nil}.
+SVN SCCS Arch MCVS)}, so it contains all six version systems that are
+currently supported. If you want VC to ignore one or more of these
+systems, exclude its name from the list. To disable VC entirely, set
+this variable to @code{nil}.
The order of systems in the list is significant: when you visit a file
registered in more than one system (@pxref{Local Version Control}),
@key{RET}}, @pxref{Merging}).
@vindex vc-cvs-global-switches
- The variable @code{vc-cvs-global-switches} should be a string
-specifying switches to pass to CVS for all CVS operations.
+ The variable @code{vc-cvs-global-switches}, if non-@code{nil},
+should be a string specifying switches to pass to CVS for all CVS
+operations.
When @code{vc-cvs-stay-local} is @code{t}, VC also makes local
version backups, so that simple diff and revert operations are
listing} is a list of all the files in a directory. Emacs provides
commands to create and delete directories, and to make directory
listings in brief format (file names only) and verbose format (sizes,
-dates, and authors included). There is also a directory browser called
-Dired; see @ref{Dired}.
+dates, and authors included). Emacs also includes a directory browser
+feature called Dired; see @ref{Dired}.
@table @kbd
@item C-x C-d @var{dir-or-pattern} @key{RET}
@vindex directory-free-space-program
@vindex directory-free-space-args
- Emacs adds information about the amount of free space on the disk
-that contains the directory. To do this, it runs the program
-specified by @code{directory-free-space-program} with arguments
+ In verbose directory listings, Emacs adds information about the
+amount of free space on the disk that contains the directory. To do
+this, it runs the program specified by
+@code{directory-free-space-program} with arguments
@code{directory-free-space-args}.
@node Comparing Files
@code{diff-switches}. The value of @code{diff-switches} should be a
string; the default is @code{"-c"} to specify a context diff.
-@findex diff-goto-source
- After running @kbd{M-x diff}, you can use @kbd{C-x `} to visit
-successive changed locations in the two source files, as in
-Compilation mode (@pxref{Compilation}.) In the @samp{*diff*} buffer,
-you can move to a particular hunk of changes and type @kbd{C-c C-c}
-(@code{diff-goto-source}) to visit the corresponding source location.
-
@findex diff-backup
The command @kbd{M-x diff-backup} compares a specified file with its most
recent backup. If you specify the name of a backup file,
@code{diff-backup} compares it with the source file that it is a backup
of.
+@findex diff-goto-source
+@findex diff-mode
+@cindex Diff mode
+ The @samp{*diff*} buffer uses Diff mode, which enables you to use
+@kbd{C-x `} to visit successive changed locations in the two source
+files, as in Compilation mode (@pxref{Compilation Mode}.) You can
+also move to a particular hunk of changes and type @kbd{C-c C-c}
+(@code{diff-goto-source}) to visit the corresponding source location.
+
+@cindex patches
+ Differences between versions of files are often distributed as
+patches, which are the output from the @command{diff} program. You
+can use Diff mode to operate on a patch by typing @kbd{M-x diff-mode}.
+
@findex compare-windows
- The command @kbd{M-x compare-windows} compares the text in the current
-window with that in the next window. Comparison starts at point in each
-window, and each starting position is pushed on the mark ring in its
-respective buffer. Then point moves forward in each window, a character
-at a time, until a mismatch between the two windows is reached. Then
-the command is finished. For more information about windows in Emacs,
-@ref{Windows}.
+ The command @kbd{M-x compare-windows} compares the text in the
+current window with that in the next window. (For more information
+about windows in Emacs, @ref{Windows}.) Comparison starts at point in
+each window, after pushing each initial point value on the mark ring
+in its respective buffer. Then it moves point forward in each window,
+one character at a time, until it reaches characters that don't match.
+Then the command exits.
+
+ If point in the two windows is followed by non-matching text when
+the command starts, @kbd{M-x compare-windows} tries heuristically to
+advance up to matching text in the two windows, and then exits. So if
+you use @kbd{M-x compare-windows} repeatedly, each time it either
+skips one matching range or finds the start of another.
@vindex compare-ignore-case
@vindex compare-ignore-whitespace
With a numeric argument, @code{compare-windows} ignores changes in
whitespace. If the variable @code{compare-ignore-case} is
non-@code{nil}, the comparison ignores differences in case as well.
-If the variable @code{compare-ignore-whitespace} is non-nil,
+If the variable @code{compare-ignore-whitespace} is non-@code{nil},
@code{compare-windows} normally ignores changes in whitespace, and a
prefix argument turns that off.
-@findex diff-mode
-@cindex diffs
-@cindex patches
-@cindex Diff mode
- Differences between versions of files are often distributed as
-@dfn{patches}, which are the output from @command{diff} or a version
-control system that uses @command{diff}. @kbd{M-x diff-mode} turns on
-Diff mode, a major mode for viewing and editing patches, either as
-``unified diffs'' or ``context diffs.''
-
@cindex Smerge mode
@findex smerge-mode
@cindex failed merges
@findex write-region
@kbd{M-x write-region} is the inverse of @kbd{M-x insert-file}; it
copies the contents of the region into the specified file. @kbd{M-x
-append-to-file} adds the text of the region to the end of the specified
-file. @xref{Accumulating Text}.
+append-to-file} adds the text of the region to the end of the
+specified file. @xref{Accumulating Text}. The variable
+@code{write-region-inhibit-fsync} applies to these commands, as well
+as saving files; see @ref{Customize Save}.
@findex delete-file
@cindex deletion (of files)
@cindex mode, Auto Compression
@pindex gzip
-@findex auto-compression-mode
-@vindex auto-compression-mode
- Emacs comes with a library that can automatically uncompress
-compressed files when you visit them, and automatically recompress them
-if you alter them and save them. To enable this feature, type the
-command @kbd{M-x auto-compression-mode}. You can enable it permanently
-by customizing the variable @code{auto-compression-mode}.
-
- When automatic compression (which implies automatic uncompression as
-well) is enabled, Emacs recognizes compressed files by their file names.
-File names ending in @samp{.gz} indicate a file compressed with
+ Emacs automatically uncompresses compressed files when you visit
+them, and automatically recompresses them if you alter them and save
+them. Emacs recognizes compressed files by their file names. File
+names ending in @samp{.gz} indicate a file compressed with
@code{gzip}. Other endings indicate other compression programs.
Automatic uncompression and compression apply to all the operations in
saving it, inserting its contents into a buffer, loading it, and byte
compiling it.
+@findex auto-compression-mode
+@vindex auto-compression-mode
+ To disable this feature, type the command @kbd{M-x
+auto-compression-mode}. You can disenable it permanently by
+customizing the variable @code{auto-compression-mode}.
+
@node File Archives
@section File Archives
@cindex mode, tar
would in Dired, and visit the subfiles contained in the archive.
However, not all Dired commands are available in Tar mode.
- If you enable Auto Compression mode (@pxref{Compressed Files}), then
+ If Auto Compression mode is enabled (@pxref{Compressed Files}), then
Tar mode is used also for compressed archives---files with extensions
@samp{.tgz}, @code{.tar.Z} and @code{.tar.gz}.
The keys @kbd{e}, @kbd{f} and @key{RET} all extract a component file
-into its own buffer. You can edit it there and when you save the buffer
-the edited version will replace the version in the Tar buffer. @kbd{v}
-extracts a file into a buffer in View mode. @kbd{o} extracts the file
-and displays it in another window, so you could edit the file and
-operate on the archive simultaneously. @kbd{d} marks a file for
+into its own buffer. You can edit it there, and if you save the
+buffer, the edited version will replace the version in the Tar buffer.
+@kbd{v} extracts a file into a buffer in View mode. @kbd{o} extracts
+the file and displays it in another window, so you could edit the file
+and operate on the archive simultaneously. @kbd{d} marks a file for
deletion when you later use @kbd{x}, and @kbd{u} unmarks a file, as in
Dired. @kbd{C} copies a file from the archive to disk and @kbd{R}
-renames a file. @kbd{g} reverts the buffer from the archive on disk.
+renames a file within the archive. @kbd{g} reverts the buffer from
+the archive on disk.
The keys @kbd{M}, @kbd{G}, and @kbd{O} change the file's permission
bits, group, and owner, respectively.
Normally, if you do not specify a user name in a remote file name,
that means to use your own user name. But if you set the variable
@code{ange-ftp-default-user} to a string, that string is used instead.
-(The Emacs package that implements FTP file access is called
-@code{ange-ftp}.)
@cindex anonymous FTP
@vindex ange-ftp-generate-anonymous-password
@code{ange-ftp-generate-anonymous-password} controls what happens: if
the value of this variable is a string, then that string is used as
the password; if non-@code{nil} (the default), then the value of
-@code{user-mail-address} is used; if @code{nil}, the user is prompted
-for a password as normal.
+@code{user-mail-address} is used; if @code{nil}, then Emacs prompts
+you for a password as usual.
@cindex firewall, and accessing remote files
@cindex gateway, and remote file access with @code{ange-ftp}
@section Quoted File Names
@cindex quoting file names
+@cindex file names, quote special characters
You can @dfn{quote} an absolute file name to prevent special
characters and syntax in it from having their special effects.
The way to do this is to add @samp{/:} at the beginning.
@node File Conveniences
@section Convenience Features for Finding Files
+ In this section, we introduce some convenient facilities for finding
+recently-opened files, reading file names from a buffer, and viewing
+image files.
+
@findex recentf-mode
@vindex recentf-mode
@findex recentf-save-list
@code{recent-file-list} to a file, and @kbd{M-x recentf-edit-list}
edits it.
-@findex auto-image-file-mode
-@findex mode, auto-image-file
-@cindex images, visiting
-@cindex visiting image files
-@vindex image-file-name-regexps
-@vindex image-file-name-extensions
- When Auto-image-file minor mode is enabled, visiting an image file
-displays it as an image, not as text. Likewise, inserting an image
-file into a buffer inserts it as an image. This works only when Emacs
-can display the relevant image type. The variables
-@code{image-file-name-extensions} or @code{image-file-name-regexps}
-control which file names are recognized as containing images.
-
The @kbd{M-x ffap} command generalizes @code{find-file} with more
powerful heuristic defaults (@pxref{FFAP}), often based on the text at
point. Partial Completion mode offers other features extending
@code{find-file}, which can be used with @code{ffap}.
@xref{Completion Options}.
+@findex image-mode
+@findex image-toggle-display
+@cindex images, viewing
+ Visiting image files automatically selects Image mode. This major
+mode allows you to toggle between displaying the file as an image in
+the Emacs buffer, and displaying its underlying text representation,
+using the command @kbd{C-c C-c} (@code{image-toggle-display}). This
+works only when Emacs can display the specific image type.
+
+@findex thumbs-mode
+@findex mode, thumbs
+ Thumbs mode is a major mode for viewing directories containing many
+image files. To use it, type @kbd{M-x thumbs} and specify the
+directory to view. The images in that directory will be displayed in
+a @samp{Thumbs} buffer as @dfn{thumbnails}; type @kbd{RET} on a
+thumbnail to view the full-size image. Thumbs mode requires the
+@file{convert} program, which is part of the ImageMagick software
+package.
+
+@node Filesets
+@section Filesets
+@cindex filesets
+
+@findex filesets-init
+ If you regularly edit a certain group of files, you can define them
+as a @dfn{fileset}. This lets you perform certain operations, such as
+visiting, @code{query-replace}, and shell commands on all the files
+at once. To make use of filesets, you must first add the expression
+@code{(filesets-init)} to your @file{.emacs} file (@pxref{Init File}).
+This adds a @samp{Filesets} menu to the menu bar.
+
+@findex filesets-add-buffer
+@findex filesets-remove-buffer
+ The simplest way to define a fileset is by adding files to it one
+at a time. To add a file to fileset @var{name}, visit the file and
+type @kbd{M-x filesets-add-buffer @kbd{RET} @var{name} @kbd{RET}}. If
+there is no fileset @var{name}, this creates a new one, which
+initially creates only the current file. The command @kbd{M-x
+filesets-remove-buffer} removes the current file from a fileset.
+
+ You can also edit the list of filesets directly, with @kbd{M-x
+filesets-edit} (or by choosing @samp{Edit Filesets} from the
+@samp{Filesets} menu). The editing is performed in a Customize buffer
+(@pxref{Easy Customization}). Filesets need not be a simple list of
+files---you can also define filesets using regular expression matching
+file names. Some examples of these more complicated filesets are
+shown in the Customize buffer. Remember to select @samp{Save for
+future sessions} if you want to use the same filesets in future Emacs
+sessions.
+
+ You can use the command @kbd{M-x filesets-open} to visit all the
+files in a fileset, and @kbd{M-x filesets-close} to close them. Use
+@kbd{M-x filesets-run-cmd} to run a shell command on all the files in
+a fileset. These commands are also available from the @samp{Filesets}
+menu, where each existing fileset is represented by a submenu.
+
@ignore
arch-tag: 768d32cb-e15a-4cc1-b7bf-62c00ee12250
@end ignore