Command Line Arguments
**********************

GNU Emacs supports command line arguments to request various actions when invoking Emacs.  These are for compatibility with other editors and for sophisticated activities.  We don't recommend using them for ordinary editing.

Arguments starting with - are options.  Other arguments specify files to visit.  Emacs visits the specified files while it starts up.  The last file name on your command line becomes the current buffer; the other files are also present in other buffers.

You can use options to specify various other things, such as the size and position of the X window Emacs uses, its colors, and so on.  A few options support advanced usage, such as running Lisp functions on files in batch mode.

There are two kinds of options: initial options and ordinary options.  Initial options must come at the beginning of the command line, in a particular order.  Ordinary options come afterward; they can appear in any order and can be intermixed with file names to visit.  These and file names are called ordinary arguments.  Emacs processes all of these in the order they are written.

Ordinary Arguments
==================

Here is a table of the ordinary arguments and options:

FILE
     Visit FILE using find-file.  See Visiting.

+LINENUM FILE
     Visit FILE using find-file, then go to line number LINENUM in it.

-l FILE
-load FILE
     Load a file FILE of Lisp code with the function load. See Lisp Libraries.

-f FUNCTION
-funcall FUNCTION
     Call Lisp function FUNCTION with no arguments.

-insert FILE
     Insert the contents of FILE into the current buffer. This is like what M-x insert-file does; see Misc File Ops.

-kill
     Exit from Emacs without asking for confirmation.

Initial Options
===============

The initial options are recognized only at the beginning of the command line.  If you use more than one of them, they must appear in the order that they appear in this table.

-t DEVICE
     Use DEVICE as the device for terminal input and output.

-d DISPLAY
     When running with the X Window System, use the display named DISPLAY to make the window that serves as Emacs's terminal.

-nw
     Don't communicate directly with X, disregarding the DISPLAY environment variable even if it is set.  -nw stands for ``non-window.''

-batch
     Run Emacs in batch mode, which means that the text being edited is not displayed and the standard terminal interrupt characters such as C-z and C-c continue to have their normal effect.  Emacs in batch mode outputs to stderr only what would normally be printed in the echo area under program control.

     Batch mode is used for running programs written in Emacs Lisp from shell scripts, makefiles, and so on.  Normally the -l option or -f option will be used as well, to invoke a Lisp program to do the batch processing.

     -batch implies -q (do not load an init file).  It also causes Emacs to kill itself after all command options have been processed.  In addition, auto-saving is not done except in buffers for which it has been explicitly requested.

-q
-no-init-file
     Do not load your Emacs init file ~/.emacs.

-no-site-file
     Do not load site-start.el.  (This file is normally loaded before ~/.emacs.)

-u USER
-user USER
     Load USER's Emacs init file ~USER/.emacs instead of your own.

-debug-init
     Enable the Emacs Lisp debugger for errors in the init file.

The init file can access the values of the command line arguments as the elements of a list in the variable command-line-args.  (The list contains only the ordinary arguments; Emacs processes the initial arguments before building the list.)  The init file can override the normal processing of the ordinary arguments by setting this variable.

Command Argument Example
========================

Here is an example of using Emacs with arguments and options.  It assumes you have a Lisp program file called hack-c.el which, when loaded, performs some useful operation on current buffer, expected to be a C program.

     emacs -batch foo.c -l hack-c -f save-buffer -kill >& log

This says to visit foo.c, load hack-c.el (which makes changes in the visited file), save foo.c (note that save-buffer is the function that C-x C-s is bound to), and then exit to the shell that this command was done with.  The initial option -batch guarantees there will be no problem redirecting output to log, because Emacs will not assume that it has a display terminal to work with.

Resuming Emacs with Arguments
=============================

You can specify ordinary arguments for Emacs when you resume it after a suspension.  To prepare for this, put the following code in your .emacs file (see Hooks):

     (add-hook 'suspend-hook 'resume-suspend-hook)

As further preparation, you must execute the shell script emacs.csh (if you use csh as your shell) or emacs.bash (if you use bash as your shell).  These scripts define an alias named edit, which will resume Emacs giving it new command line arguments such as files to visit.

Only ordinary arguments work properly when you resume Emacs.  Initial arguments are not recognized---it's too late to execute them anyway.

Note that resuming Emacs (with or without arguments) must be done from within the shell that is the parent of the Emacs job.  This is why edit is an alias rather than a program or a shell script.  It is not possible to implement a resumption command that could be run from other subjobs of the shell; no way to define a command that could be made the value of EDITOR, for example.  Therefore, this feature does not take the place of the the Emacs Server feature.  See Emacs Server.

The aliases use the Emacs Server feature if you appear to have a server Emacs running.  However, they cannot determine this with complete accuracy.  They may think that a server is still running when in actuality you have killed that Emacs, because the file /tmp/.esrv... still exists.  If this happens, find that file and delete it.

Environment Variables
=====================

This appendix describes how Emacs uses environment variables.  An environment variable is a string passed from the operating system to Emacs, and the collection of environment variables is known as the environment.  Environment variable names are case sensitive and it is conventional to use upper case letters only.

Because environment variables come from the operating system there is no general way to set them; it depends on the operating system and especially the shell that you are using.  For example, here's how to set the environment variable ORGANIZATION to not very much using bash:

     export ORGANIZATION="not very much"

and here's how to do it in csh or tcsh:

     setenv ORGANIZATION "not very much"

When Emacs is set-up to use the X windowing system, it inherits the use of a large number of environment variables from the X library.  See the X documentation for more information.

General Variables
-----------------

AUTHORCOPY
     The name of a file used to archive news articles posted with the GNUS package.

CDPATH
     Used by the cd command.

DOMAINNAME
     The name of the internet domain that the machine running Emacs is located in.  Used by the GNUS package.

EMACSDATA
     Used to initialize the variable data-directory used to locate the architecture-independent files that come with Emacs.  Setting this variable overrides the setting in paths.h when Emacs was built.

EMACSLOADPATH
     A colon-separated list of directories from which to load Emacs Lisp files.  Setting this variable overrides the setting in paths.h when Emacs was built.

EMACSLOCKDIR
     The directory that Emacs places lock files---files used to protect users from editing the same files simultaneously.  Setting this variable overrides the setting in paths.h when Emacs was built.

EMACSPATH
     The location of Emacs-specific binaries.  Setting this variable overrides the setting in paths.h when Emacs was built.

ESHELL
     Used for shell-mode to override the SHELL environment variable.

HISTFILE
     The name of the file that shell commands are saved in between logins. This variable defaults to ~/.history if you use (t)csh as shell, to ~/.bash_history if you use bash, to ~/.sh_history if you use ksh, and to ~/.history otherwise.

HOME
     The location of the user's files in the directory tree; used for expansion of file names starting with a tilde (~).  On MS-DOS, it defaults to the directory from which Emacs was started, with /bin removed from the end if it was present.

HOSTNAME
     The name of the machine that Emacs is running on.

INCPATH
     A colon-separated list of directories.  Used by the complete package to search for files.

INFOPATH
     A colon separated list of directories holding info files.  Setting this variable overrides the setting in paths.el when Emacs was built.

LOGNAME
     The user's login name.  See also USER.

MAIL
     The name of the user's system mail box.

MAILRC
     Name of file containing mail aliases.  This defaults to ~/.mailrc.

MH
     Name of setup file for the mh system.  This defaults to ~/.mh_profile.

NAME
     The real-world name of the user.

NNTPSERVER
     The name of the news server.  Used by the mh and GNUS packages.

ORGANIZATION
     The name of the organization to which you belong.  Used for setting the `Organization:' header in your posts from the GNUS package.

PATH
     A colon-separated list of directories in which executables reside.  (On MS-DOS, it is semicolon-separated instead.)  This variable is used to set the Emacs Lisp variable exec-path which you should consider to use instead.

PWD
     If set, this should be the default directory when Emacs was started.

SAVEDIR
     The name of a directory in which news articles are saved by default. Used by the GNUS package.

SHELL
     The name of an interpreter used to parse and execute programs run from inside Emacs.

TERM
     The name of the terminal that Emacs is running on.  The variable must be set unless Emacs is run in batch mode.  On MS-DOS, it defaults to internal, which specifies a built-in terminal emulation that handles the machine's own display.

TERMCAP
     The name of the termcap library file describing how to program the terminal specified by the TERM variable.  This defaults to /etc/termcap.

TMPDIR
     Used by the Emerge package as a prefix for temporary files.

TZ
     This specifies the current time zone and possibly also daylight savings information.  On MS-DOS, the default is based on country code; see the file msdos.c for details.

USER
     The user's login name.  See also LOGNAME.  On MS-DOS, this defaults to root.

VERSION_CONTROL
     Used to initialize the version-control variable (see Backup Names).

Misc Variables
--------------

These variables are used only on particular configurations:

COMSPEC
     On MS-DOS, the name of the command interpreter to use.  This is used to make a default value for the SHELL environment variable.

NAME
     On MS-DOS, this variable defaults to the value of the USER variable.

TEMP
TMP
     On MS-DOS, these specify the name of the directory for storing temporary files in.

USE_DOMAIN_ACLS
     Used for Apollo machines to enable access control lists.

WINDOW_GFX
     Used when initializing the Sun windows system.

Specifying the Display Name
===========================

The environment variable DISPLAY tells all X clients, including Emacs, where to display their windows.  Its value is set up by default in ordinary circumstances, when you start an X server and run jobs locally.  Occasionally you may need to specify the display yourself; for example, if you do a remote login and want to run a client program remotely, displaying on your local screen.

With Emacs, the main reason people change the default display is to let them log into another system, run Emacs on that system, but have the window displayed at their local terminal.  You might need to use login to another system because the files you want to edit are there, or because the Emacs executable file you want to run is there.

The syntax of the DISPLAY environment variable is HOST:DISPLAY.SCREEN, where HOST is the host name of the X Window System server machine, DISPLAY is an arbitrarily-assigned number that distinguishes your server (X terminal) from other servers on the same machine, and SCREEN is a rarely-used field that allows an X server to control multiple terminal screens.  The period and the SCREEN field are optional.  If included, SCREEN is usually zero.

For example, if your host is named glasperle and your server is the first (or perhaps the only) server listed in the configuration, your DISPLAY is glasperle:0.0.

You can specify the display name explicitly when you run Emacs, either by changing the DISPLAY variable, or with the option -d DISPLAY or -display DISPLAY.  These are initial options; they must come at the beginning of the command line. See Initial Options.  Here is an example:

     emacs -display glasperle:0 &

You can inhibit the direct use of X with the -nw option.  This is also an initial option.  This option tells Emacs to display using ordinary ASCII on its controlling terminal.

Sometimes, security arrangements prevent a program on a remote system from displaying on your local system.  In this case, trying to run Emacs produces messages like this:

     Xlib:  connection to "glasperle:0.0" refused by server

You might be able to overcome this problem by using the xhost command on the local system to give permission for access from your remote machine.

Font Specification Options
==========================

By default, Emacs displays text in the font named 9x15, which makes each character nine pixels wide and fifteen pixels high.  You can specify a different font on your command line through the option -fn NAME.

-fn NAME
     Use font NAME as the default font.

-font NAME
     -font is an alias for -fn.

Under X, each font has a long name which consists of eleven words or numbers, separated by dashes.  Some fonts also have shorter nicknames---9x15 is such a nickname.  You can use either kind of name.  You can use wild card patterns for the font name; then Emacs lets X choose one of the fonts that match the pattern.  Here is an example, which happens to specify the font whose nickname is 6x13:

     emacs -fn "-misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1" &

You can also specify the font in your .Xdefaults file:

     emacs.font: -misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1

A long font name has the following form:

     -MAKER-FAMILY-WEIGHT-SLANT-WIDTHTYPE-STYLE...
     ...-PIXELS-HEIGHT-HORIZ-VERT-SPACING-WIDTH-CHARSET

family
     This is the name of the font family--for example, courier.

weight
     This is normally bold, medium or light.  Other words may appear here in some font names.

slant
     This is r (roman), i (italic), o (oblique), ri (reverse italic), or ot (other).

widthtype
     This is normally condensed, extended, semicondensed or normal.  Other words may appear here in some font names.

style
     This is an optional additional style name.  Usually it is empty---most long font names have two hyphens in a row at this point.

pixels
     This is the font height, in pixels.

height
     This is the font height on the screen, measured in printer's points (approximately 1/72 of an inch), times ten.  For a given vertical resolution, HEIGHT and PIXELS are proportional; therefore, it is common to specify just one of them and use * for the other.

horiz
     This is the horizontal resolution, in pixels per inch, of the screen for which the font is intended.

vert
     This is the vertical resolution, in dots per inch, of the screen for which the font is intended.  Normally the resolution of the fonts on your system is the right value for your screen; therefore, you normally specify * for this and HORIZ.

spacing
     This is m (monospace), p (proportional) or c (character cell).  Emacs can use m and c fonts.

width
     This is the average character width, in pixels, times ten.

charset
     This is the character set that the font depicts. Normally you should use iso8859-1.

Use only fixed width fonts---that is, fonts in which all characters have the same width; Emacs cannot yet handle display properly for variable width fonts.  Any font with m or c in the SPACING field of the long name is a fixed width font.  Here's how to use the xlsfonts program to list all the fixed width fonts available on your system:

     xlsfonts -fn '*x*'
     xlsfonts -fn '*-*-*-*-*-*-*-*-*-*-*-m*'
     xlsfonts -fn '*-*-*-*-*-*-*-*-*-*-*-c*'

To see what a particular font looks like, use the xfd command. For example:

     xfd -fn 6x13

displays the entire font 6x13.

While running Emacs, you can set the font of the current frame (see Frame Parameters) or for a specific kind of text (see Faces).

Window Color Options
====================

On a color display, you can specify which color to use for various parts of the Emacs display.  To find out what colors are available on your system, look at the /usr/lib/X11/rgb.txt file.  If you do not specify colors, the default for the background is white and the default for all other colors is black.  On a monochrome (black and white) display, the foreground is black, the background is white, and the border is grey.

Here is a list of the options for specifying colors:

-fg COLOR
     Specify the foreground color.

-bg COLOR
     Specify the background color.

-bd COLOR
     Specify the color of the border of the X window.

-cr COLOR
     Specify the color of the Emacs cursor which indicates where point is.

-ms COLOR
     Specify the color for the mouse cursor when the mouse is in the Emacs window.

-r
     Reverse video---swap the foreground and background colors.

For example, to use a coral mouse cursor and a slate blue text cursor, enter:

     emacs -ms coral -cr 'slate blue' &

You can reverse the foreground and background colors through the -r option or with the X resource reverseVideo.

Options for Window Geometry
===========================

The -geometry option controls the size and position of the initial Emacs frame.  Here is the format for specifying the window geometry:

-geometry WIDTHxHEIGHT{+-}XOFFSET{+-}YOFFSET
     Specify window size WIDTH and HEIGHT (measured in character columns and lines), and positions XOFFSET and YOFFSET (measured in pixels).

A positive XOFFSET specifies the distance from the left side of the screen, a negative XOFFSET specifies the distance from the right side of the screen, a positive YOFFSET specifies the distance from the top of the screen, and a negative YOFFSET specifies the distance from the bottom of the screen.

Emacs uses the same units as xterm does to interpret the geometry. The WIDTH and HEIGHT are measured in characters, so a large font creates a larger frame than a small font.  The XOFFSET and YOFFSET are measured in pixels.

Since the mode line and the echo area occupy the last 2 lines of the frame, the height of the initial text window is 2 less than the height specified in your geometry.  In non-toolkit versions of Emacs, the menu bar also takes one line of the specified number.

You do not have to specify all of the fields in the geometry specification.

If you omit both XOFFSET and YOFFSET, the window manager decides where to put the Emacs frame, possibly by letting you place it with the mouse.  For example, 164x55 specifies a window 164 columns wide, enough for two ordinary width windows side by side, and 55 lines tall.

The default width for Emacs is 80 characters and the default height is 40 lines.  You can omit either the width or the height or both.  If you start the geometry with an integer, Emacs interprets it as the width.  If you start with an x followed by an integer, Emacs interprets it as the height.  Thus, 81 specifies just the width; x45 specifies just the height.

If you start with + or -, that introduces an offset, which means both sizes are omitted.  Thus, -3 specifies the XOFFSET only.  (If you give just one offset, it is always XOFFSET.)  +3-3 specifies both the XOFFSET and the YOFFSET, placing the frame near the bottom left of the screen.

You can specify a default for any or all of the fields in .Xdefaults file, and then override selected fields through a -geometry option.

Internal and External Borders
=============================

An Emacs frame has an internal border and an external border.  The internal border is an extra strip of the background color around all four edges of the frame.  Emacs itself adds the internal border.  The external border is added by the window manager outside the internal border; it may contain various boxes you can click on to move or iconify the window.

-ib WIDTH
     Specify WIDTH as the width of the internal border.

-bw WIDTH
     Specify WIDTH as the width of the main border.

When you specify the size of the frame, that does not count the borders.  The frame's position is measured from the outside edge of the external border.

Use the -ib N option to specify an internal border N pixels wide.  The default is 1.  Use -bw N to specify the width of the external border (though the window manager may not pay attention to what you specify).  The default width of the external border is 2.

Icons
=====

Most window managers allow the user to ``iconify'' a frame, removing it from sight, and leaving a small, distinctive ``icon'' window in its place.  Clicking on the icon window makes the frame itself appear again. If you have many clients running at once, you can avoid cluttering up the screen by iconifying most of the clients.

-i
-itype
     Use a picture of a gnu as the Emacs icon.

-iconic
     Start Emacs in iconified state.

The -i and -itype option tells Emacs to use an icon window containing a picture of the GNU gnu.  If omitted, Emacs lets the window manager choose what sort of icon to use---usually just a small rectangle containing the frame's title.

The -iconic option tells Emacs to begin running as an icon, rather than opening a frame right away.  In this situation, the icon window provides only indication that Emacs has started; the usual text frame doesn't appear until you deiconify it.

X Resources
===========

Programs running under the X Window System organize their user options under a hierarchy of classes and resources.  You can specify default values for these options in your X resources file, usually named ~/.Xdefaults.

Each line in the file specifies a value for one option or for a collection of related options, for one program or for several programs (optionally even for all programs).

Programs define named resources with particular meanings.  They also define how to group resources into named classes.  For instance, in Emacs, the internalBorder resource controls the width of the internal border, and the borderWidth resource controls the width of the external border.  Both of these resources are part of the BorderWidth class.  Case distinctions are significant in these names.

In ~/.Xdefaults, you can specify a value for a single resource on one line, like this:

     emacs.borderWidth: 2

Or you can use a class name to specify the same value for all resources in that class.  Here's an example:

     emacs.BorderWidth: 2

If you specify a value for a class, it becomes the default for all resources in that class.  You can specify values for individual resources as well; these override the class value, for those particular resources.  Thus, this example specifies 2 as the default width for all borders, but overrides this value with 4 for the external border:

     emacs.Borderwidth: 2
     emacs.borderwidth: 4

The order in which the lines appear in the file does not matter. Also, command-line options always override the X resources file.

The string emacs in the examples above is also a resource name.  It actually represents the name of the executable file that you invoke to run Emacs.  If Emacs is installed under a different name, it looks for resources under that name instead of emacs.

When Emacs creates a new frame, it may or may not have a specified title.  The frame title, if specified, appears in window decorations and icons as the name of the frame.  It is also used (instead of the Emacs executable's name) to look up all the resources for that frame.  The option -name specifies a frame title for the initial frame. Subsequent frames normally have no frame title, but Lisp programs can specify a title when they create frames.

-name NAME
     Use NAME as the title of the initial frame.

For consistency, -name also specifies the name to use for other resource values that do not belong to any particular frame.

The resources that name Emacs invocations also belong to a class; its name is Emacs.  To specify options for all Emacs jobs, no matter what name is used to run them, write Emacs instead of emacs, like this:

     Emacs.BorderWidth: 2
     Emacs.borderWidth: 4

You can specify a string of additional resource values for Emacs to use with the command line option -xrm RESOURCES.  The text RESOURCES should have the same format that you would use inside a file of X resources.  To include multiple resource specifications in DATA, put a newline between them, just as you would in a file. You can also use #include "FILENAME" to include a file full of resource specifications.  Resource values specified with -xrm take precedence over all other resource specifications.

The following table lists the resource names that designate options for Emacs, each with the class that it belongs to:

background (class Background)
     Background color name.

bitmapIcon (class BitmapIcon)
     Use a bitmap icon (a picture of a gnu) if on, let the window manager choose an icon if off.

borderColor (class BorderColor)
     Color name for the external border.

borderWidth (class BorderWidth)
     Width in pixels of the external border.

cursorColor (class Foreground)
     Color name for text cursor (point).

font (class Font)
     Font name for text.

foreground (class Foreground)
     Color name for text.

geometry (class Geometry)
     Window size and position.  Be careful not to specify this resource as emacs*geometry, because that may affect individual menus as well as the Emacs frame itself.

iconName (class Title)
     Name to display in the icon.

internalBorder (class BorderWidth)
     Width in pixels of the internal border.

paneFont (class Font)
     Font name for menu pane titles, in non-toolkit versions of Emacs.

pointerColor (class Foreground)
     Color of the mouse cursor.

reverseVideo (class ReverseVideo)
     Switch foreground and background default colors if on, use colors as specified if off.

selectionFont (class Font)
     Font name for pop-up menu items, in non-toolkit versions of Emacs. (Toolkit versions, use emacs.shell.menu.popup.font instead---see below.)

title (class Title)
     Name to display in the title bar of the initial Emacs frame.

If the Emacs installed at your site was built to use an X toolkit, then the menu bar is a separate widget and has its own resources.  Their names start with shell.pane.menubar; specify them like this:

     Emacs.shell.pane.menubar.RESOURCE:  VALUE

For example, to specify the font 8x16 for the menu bar items, write this:

     Emacs.shell.pane.menubar.font:  8x16

or, for short, like this:

     Emacs*menubar.font:  8x16

Resources for toolkit popup menus have shell.menu.popup, in like fashion.  For example, to specify the font 8x16 for the menu bar items, write this:

     Emacs.shell.menu.popup.font:	8x16

Here is a list of the specific resources for menu bars and popup menus:

font
     Font for menu item text.

foreground
     Color of the foreground.

background
     Color of the background.

buttonForeground
     In the menu bar, the color of the foreground for a selected item.

horizontalSpacing
     Horizontal spacing in pixels between items.  Default is 3.

verticalSpacing
     Vertical spacing in pixels between items.  Default is 1.

arrowSpacing
     Horizontal spacing between the arrow (which indicates a submenu) and the associated text.  Default is 10.

shadowThickness
     Thickness of shadow line around the widget.

Here are resources for controlling the appearance of particular faces (see Faces):

FACE.attributeFont
     Font for face FACE.

FACE.attributeForeground
     Foreground color for face FACE.

FACE.attributeBackground
     Background color for face FACE.

FACE.attributeUnderline
     Underline flag for face FACE.