TWM(1) MachTen Programmer’s Manual TWM(1)

NAME
twm - Tab Window Manager for the X Window System

SYNTAX
twm [ -display dpy ] [ -s ] [ -f initfile ] [ -v ]

DESCRIPTION
Twm is a window manager for the X Window System. It pro-
vides titlebars, shaped windows, several forms of icon
management, user-defined macro functions, click-to-type
and pointer-driven keyboard focus, and user-specified key
and pointer button bindings.

This program is usually started by the user’s session man-
ager or startup script. When used from xdm(1) or xinit(1)
without a session manager, twm is frequently executed in
the foreground as the last client. When run this way,
exiting twm causes the session to be terminated (i.e.,
logged out).

By default, application windows are surrounded by a
‘‘frame’’ with a titlebar at the top and a special border
around the window. The titlebar contains the window’s
name, a rectangle that is lit when the window is receiving
keyboard input, and function boxes known as ‘‘titlebut-
tons’’ at the left and right edges of the titlebar.

Pressing pointer Button1 (usually the left-most button
unless it has been changed with xmodmap) on a titlebutton
will invoke the function associated with the button. In
the default interface, windows are iconified by clicking
(pressing and then immediately releasing) the left title-
button (which looks like a Dot). Conversely, windows are
deiconified by clicking in the associated icon or entry in
the icon manager (see description of the variable Show-
IconManager and of the function f.showiconmgr).

Windows are resized by pressing the right titlebutton
(which resembles a group of nested squares), dragging the
pointer over edge that is to be moved, and releasing the
pointer when the outline of the window is the desired
size. Similarly, windows are moved by pressing in the
title or highlight region, dragging a window outline to
the new location, and then releasing when the outline is
in the desired position. Just clicking in the title or
highlight region raises the window without moving it.

When new windows are created, twm will honor any size and
location information requested by the user (usually
through -geometry command line argument or resources for
the individual applications). Otherwise, an outline of
the window’s default size, its titlebar, and lines divid-
ing the window into a 3x3 grid that track the pointer are
displayed. Clicking pointer Button1 will position the
window at the current position and give it the default
size. Pressing pointer Button2 (usually the middle
pointer button) and dragging the outline will give the
window its current position but allow the sides to be
resized as described above. Clicking pointer Button3
(usually the right pointer button) will give the window
its current position but attempt to make it long enough to
touch the bottom the screen.

OPTIONS
Twm accepts the following command line options:

-display dpy
This option specifies the X server to use.

-s This option indicates that only the default screen
(as specified by -display or by the DISPLAY envi-
ronment variable) should be managed. By default,
twm will attempt to manage all screens on the dis-
play.

-f filename
This option specifies the name of the startup file
to use. By default, twm will look in the user’s
home directory for files named .twmrc.num (where
num is a screen number) or .twmrc.

-v This option indicates that twm should print error
messages whenever an unexpected X Error event is
received. This can be useful when debugging
applications but can be distracting in regular
use.

CUSTOMIZATION
Much of twm’s appearance and behavior can be controlled by
providing a startup file in one of the following locations
(searched in order for each screen being managed when twm
begins):

$HOME/.twmrc.screennumber
The screennumber is a small positive number (e.g.
0, 1, etc.) representing the screen number (e.g.
the last number in the DISPLAY environment vari-
able host:displaynum.screennum) that would be used
to contact that screen of the display. This is
intended for displays with multiple screens of
differing visual types.

$HOME/.twmrc
This is the usual name for an individual user’s
startup file.

<XRoot>/lib/X11/twm/system.twmrc
If neither of the preceding files are found, twm
will look in this file for a default configura-
tion. This is often tailored by the site adminis-
trator to provide convenient menus or familiar
bindings for novice users. <XRoot> refers to the
root of the X11 install tree.

If no startup files are found, twm will use the built-in
defaults described above. The only resource used by twm
is bitmapFilePath for a colon-separated list of directo-
ries to search when looking for bitmap files (for more
information, see the Athena Widgets manual and xrdb(1)).

Twm startup files are logically broken up into three types
of specifications: Variables, Bindings, Menus. The Vari-
ables section must come first and is used to describe the
fonts, colors, cursors, border widths, icon and window
placement, highlighting, autoraising, layout of titles,
warping, use of the icon manager. The Bindings section
usually comes second and is used to specify the functions
that should be to be invoked when keyboard and pointer
buttons are pressed in windows, icons, titles, and frames.
The Menus section gives any user-defined menus (containing
functions to be invoked or commands to be executed).

Variable names and keywords are case-insensitive. Strings
must be surrounded by double quote characters (e.g.
"blue") and are case-sensitive. A pound sign (#) outside
of a string causes the remainder of the line in which the
character appears to be treated as a comment.

VARIABLES
Many of the aspects of twm’s user interface are controlled
by variables that may be set in the user’s startup file.
Some of the options are enabled or disabled simply by the
presence of a particular keyword. Other options require
keywords, numbers, strings, or lists of all of these.

Lists are surrounded by braces and are usually separated
by whitespace or a newline. For example:

AutoRaise { "emacs" "XTerm" "Xmh" }

or

AutoRaise
{
"emacs"
"XTerm"
"Xmh"
}

When a variable containing a list of strings representing
windows is searched (e.g. to determine whether or not to
enable autoraise as shown above), a string must be an
exact, case-sensitive match to the window’s name (given by
the WM_NAME window property), resource name or class name
(both given by the WM_CLASS window property). The preced-
ing example would enable autoraise on windows named
‘‘emacs’’ as well as any xterm (since they are of class
‘‘XTerm’’) or xmh windows (which are of class ‘‘Xmh’’).

String arguments that are interpreted as filenames (see
the Pixmaps, Cursors, and IconDirectory below) will
prepend the user’s directory (specified by the HOME envi-
ronment variable) if the first character is a tilde (~).
If, instead, the first character is a colon (:), the name
is assumed to refer to one of the internal bitmaps that
are used to create the default titlebars symbols: :xlogo
or :delete (both refer to the X logo), :dot or :iconify
(both refer to the dot), :resize (the nested squares used
by the resize button), :menu (a page with lines), and
:question (the question mark used for non-existent bitmap
files).

The following variables may be specified at the top of a
twm startup file. Lists of Window name prefix strings are
indicated by win-list. Optional arguments are shown in
square brackets:

AutoRaise { win-list }
This variable specifies a list of windows that
should automatically be raised whenever the
pointer enters the window. This action can be
interactively enabled or disabled on individual
windows using the function f.autoraise.

AutoRelativeResize
This variable indicates that dragging out a window
size (either when initially sizing the window with
pointer Button2 or when resizing it) should not
wait until the pointer has crossed the window
edges. Instead, moving the pointer automatically
causes the nearest edge or edges to move by the
same amount. This allows the resizing of windows
that extend off the edge of the screen. If the
pointer is in the center of the window, or if the
resize is begun by pressing a titlebutton, twm
will still wait for the pointer to cross a window
edge (to prevent accidents). This option is par-
ticularly useful for people who like the press-
drag-release method of sweeping out window sizes.

BorderColor string [{ wincolorlist }]
This variable specifies the default color of the
border to be placed around all non-iconified win-
dows, and may only be given within a Color,
Grayscale or Monochrome list. The optional win-
colorlist specifies a list of window and color
name pairs for specifying particular border colors
for different types of windows. For example:

BorderColor "gray50"
{
"XTerm" "red"
"xmh" "green"
}

The default is "black".

BorderTileBackground string [{ wincolorlist }]
This variable specifies the default background
color in the gray pattern used in unhighlighted
borders (only if NoHighlight hasn’t been set), and
may only be given within a Color, Grayscale or
Monochrome list. The optional wincolorlist allows
per-window colors to be specified. The default
is "white".

BorderTileForeground string [{ wincolorlist }]
This variable specifies the default foreground
color in the gray pattern used in unhighlighted
borders (only if NoHighlight hasn’t been set), and
may only be given within a Color, Grayscale or
Monochrome list. The optional wincolorlist allows
per-window colors to be specified. The default is
"black".

BorderWidth pixels
This variable specifies the width in pixels of the
border surrounding all client window frames if
ClientBorderWidth has not been specified. This
value is also used to set the border size of win-
dows created by twm (such as the icon manager).
The default is 2.

ButtonIndent pixels
This variable specifies the amount by which title-
buttons should be indented on all sides. Positive
values cause the buttons to be smaller than the
window text and highlight area so that they stand
out. Setting this and the TitleButtonBorderWidth
variables to 0 makes titlebuttons be as tall and
wide as possible. The default is 1.

ClientBorderWidth
This variable indicates that border width of a
window’s frame should be set to the initial border
width of the window, rather than to the value of
BorderWidth.

Color { colors-list }
This variable specifies a list of color assign-
ments to be made if the default display is capable
of displaying more than simple black and white.
The colors-list is made up of the following color
variables and their values: DefaultBackground,
DefaultForeground, MenuBackground, MenuForeground,
MenuTitleBackground, MenuTitleForeground,
MenuShadowColor, PointerForeground, and Pointer-
Background. The following color variables may
also be given a list of window and color name
pairs to allow per-window colors to be specified
(see BorderColor for details): BorderColor, Icon-
ManagerHighlight, BorderTitleBackground, BorderTi-
tleForeground, TitleBackground, TitleForeground,
IconBackground, IconForeground, IconBorderColor,
IconManagerBackground, and IconManagerForeground.
For example:

Color
{
MenuBackground "gray50"
MenuForeground "blue"
BorderColor "red" { "XTerm" "yellow" }
TitleForeground "yellow"
TitleBackground "blue"
}

All of these color variables may also be specified
for the Monochrome variable, allowing the same
initialization file to be used on both color and
monochrome displays.

ConstrainedMoveTime milliseconds
This variable specifies the length of time between
button clicks needed to begin a constrained move
operation. Double clicking within this amount of
time when invoking f.move will cause the window to
be moved only in a horizontal or vertical direc-
tion. Setting this value to 0 will disable con-
strained moves. The default is 400 milliseconds.

Cursors { cursor-list }
This variable specifies the glyphs that twm should
use for various pointer cursors. Each cursor may
be defined either from the cursor font or from two
bitmap files. Shapes from the cursor font may be
specified directly as:

cursorname "string"

where cursorname is one of the cursor names listed
below, and string is the name of a glyph as found
in the file <XRoot>/include/X11/cursorfont.h
(without the ‘‘XC_’’ prefix). If the cursor is to
be defined from bitmap files, the following syntax
is used instead:

cursorname "image" "mask"

The image and mask strings specify the names of
files containing the glyph image and mask in
bitmap(1) form. The bitmap files are located in
the same manner as icon bitmap files. The follow-
ing example shows the default cursor definitions:

Cursors
{
Frame "top_left_arrow"
Title "top_left_arrow"
Icon "top_left_arrow"
IconMgr "top_left_arrow"
Move "fleur"
Resize "fleur"
Menu "sb_left_arrow"
Button "hand2"
Wait "watch"
Select "dot"
Destroy "pirate"
}

DecorateTransients
This variable indicates that transient windows
(those containing a WM_TRANSIENT_FOR property)
should have titlebars. By default, transients are
not reparented.

DefaultBackground string
This variable specifies the background color to be
used for sizing and information windows. The
default is "white".

DefaultForeground string
This variable specifies the foreground color to be
used for sizing and information windows. The
default is "black".

DontIconifyByUnmapping { win-list }
This variable specifies a list of windows that
should not be iconified by simply unmapping the
window (as would be the case if IconifyByUnmapping
had been set). This is frequently used to force
some windows to be treated as icons while other
windows are handled by the icon manager.

DontMoveOff
This variable indicates that windows should not be
allowed to be moved off the screen. It can be
overridden by the f.forcemove function.

DontSqueezeTitle [{ win-list }]
This variable indicates that titlebars should not
be squeezed to their minimum size as described
under SqueezeTitle below. If the optional window
list is supplied, only those windows will be pre-
vented from being squeezed.

ForceIcons
This variable indicates that icon pixmaps speci-
fied in the Icons variable should override any
client-supplied pixmaps.

FramePadding pixels
This variable specifies the distance between the
titlebar decorations (the button and text) and the
window frame. The default is 2 pixels.

Grayscale { colors }
This variable specifies a list of color assign-
ments that should be made if the screen has a
GrayScale default visual. See the description of
Colors.

IconBackground string [{ win-list }]
This variable specifies the background color of
icons, and may only be specified inside of a
Color, Grayscale or Monochrome list. The optional
win-list is a list of window names and colors so
that per-window colors may be specified. See the
BorderColor variable for a complete description of
the win-list. The default is "white".

IconBorderColor string [{ win-list }]
This variable specifies the color of the border
used for icon windows, and may only be specified
inside of a Color, Grayscale or Monochrome list.
The optional win-list is a list of window names
and colors so that per-window colors may be speci-
fied. See the BorderColor variable for a complete
description of the win-list. The default is
"black".

IconBorderWidth pixels
This variable specifies the width in pixels of the
border surrounding icon windows. The default is
2.

IconDirectory string
This variable specifies the directory that should
be searched if if a bitmap file cannot be found in
any of the directories in the bitmapFilePath
resource.

IconFont string
This variable specifies the font to be used to
display icon names within icons. The default is
"variable".

IconForeground string [{ win-list }]
This variable specifies the foreground color to be
used when displaying icons, and may only be speci-
fied inside of a Color, Grayscale or Monochrome
list. The optional win-list is a list of window
names and colors so that per-window colors may be
specified. See the BorderColor variable for a
complete description of the win-list. The default
is "black".

IconifyByUnmapping [{ win-list }]
This variable indicates that windows should be
iconified by being unmapped without trying to map
any icons. This assumes that the user will remap
the window through the icon manager, the f.warpto
function, or the TwmWindows menu. If the optional
win-list is provided, only those windows will be
iconified by simply unmapping. Windows that have
both this and the IconManagerDontShow options set
may not be accessible if no binding to the TwmWin-
dows menu is set in the user’s startup file.

IconManagerBackground string [{ win-list }]
This variable specifies the background color to
use for icon manager entries, and may only be
specified inside of a Color, Grayscale or
Monochrome list. The optional win-list is a list
of window names and colors so that per-window col-
ors may be specified. See the BorderColor vari-
able for a complete description of the win-list.
The default is "white".

IconManagerDontShow [{ win-list }]
This variable indicates that the icon manager
should not display any windows. If the optional
win-list is given, only those windows will not be
displayed. This variable is used to prevent win-
dows that are rarely iconified (such as xclock or
xload) from taking up space in the icon manager.

IconManagerFont string
This variable specifies the font to be used when
displaying icon manager entries. The default is
"variable".

IconManagerForeground string [{ win-list }]
This variable specifies the foreground color to be
used when displaying icon manager entries, and may
only be specified inside of a Color, Grayscale or
Monochrome list. The optional win-list is a list
of window names and colors so that per-window col-
ors may be specified. See the BorderColor vari-
able for a complete description of the win-list.
The default is "black".

IconManagerGeometry string [ columns ]
This variable specifies the geometry of the icon
manager window. The string argument is standard
geometry specification that indicates the initial
full size of the icon manager. The icon manager
window is then broken into columns pieces and
scaled according to the number of entries in the
icon manager. Extra entries are wrapped to form
additional rows. The default number of columns is
1.

IconManagerHighlight string [{ win-list }]
This variable specifies the border color to be
used when highlighting the icon manager entry that
currently has the focus, and can only be specified
inside of a Color, Grayscale or Monochrome list.
The optional win-list is a list of window names
and colors so that per-window colors may be speci-
fied. See the BorderColor variable for a complete
description of the win-list. The default is
"black".

IconManagers { iconmgr-list }
This variable specifies a list of icon managers to
create. Each item in the iconmgr-list has the

following format:

"winname" ["iconname"] "geometry" columns

where winname is the name of the windows that
should be put into this icon manager, iconname is
the name of that icon manager window’s icon, geom-
etry is a standard geometry specification, and
columns is the number of columns in this icon man-
ager as described in IconManagerGeometry. For
example:

IconManagers
{
"XTerm" "=300x5+800+5" 5
"myhost" "=400x5+100+5" 2
}

Clients whose name or class is ‘‘XTerm’’ will have
an entry created in the ‘‘XTerm’’ icon manager.
Clients whose name was ‘‘myhost’’ would be put
into the ‘‘myhost’’ icon manager.

IconManagerShow { win-list }
This variable specifies a list of windows that
should appear in the icon manager. When used in
conjunction with the IconManagerDontShow variable,
only the windows in this list will be shown in the
icon manager.

IconRegion geomstring vgrav hgrav gridwidth gridheight
This variable specifies an area on the root window
in which icons are placed if no specific icon
location is provided by the client. The geom-
string is a quoted string containing a standard
geometry specification. If more than one IconRe-
gion lines are given, icons will be put into the
succeeding icon regions when the first is full.
The vgrav argument should be either North or South
and control and is used to control whether icons
are first filled in from the top or bottom of the
icon region. Similarly, the hgrav argument should
be either East or West and is used to control
whether icons should be filled in from left from
the right. Icons are laid out within the region
in a grid with cells gridwidth pixels wide and
gridheight pixels high.

Icons { win-list }
This variable specifies a list of window names and
the bitmap filenames that should be used as their
icons. For example:

Icons
{
"XTerm" "xterm.icon"
"xfd" "xfd_icon"
}

Windows that match ‘‘XTerm’’ and would not be
iconified by unmapping, and would try to use the
icon bitmap in the file ‘‘xterm.icon’’. If Force-
Icons is specified, this bitmap will be used even
if the client has requested its own icon pixmap.

InterpolateMenuColors
This variable indicates that menu entry colors
should be interpolated between entry specified
colors. In the example below:

Menu "mymenu"
{
"Title" ("black":"red") f.title
"entry1" f.nop
"entry2" f.nop
"entry3" ("white":"green") f.nop
"entry4" f.nop
"entry5" ("red":"white") f.nop
}

the foreground colors for ‘‘entry1’’ and
‘‘entry2’’ will be interpolated between black and
white, and the background colors between red and
green. Similarly, the foreground for ‘‘entry4’’
will be half-way between white and red, and the
background will be half-way between green and
white.

MakeTitle { win-list }
This variable specifies a list of windows on which
a titlebar should be placed and is used to request
titles on specific windows when NoTitle has been
set.

MaxWindowSize string
This variable specifies a geometry in which the
width and height give the maximum size for a given
window. This is typically used to restrict win-
dows to the size of the screen. The default width
is 32767 - screen width. The default height is
32767 - screen height.

MenuBackground string
This variable specifies the background color used
for menus, and can only be specified inside of a
Color or Monochrome list. The default is "white".

MenuFont string
This variable specifies the font to use when dis-
playing menus. The default is "variable".

MenuForeground string
This variable specifies the foreground color used
for menus, and can only be specified inside of a
Color, Grayscale or Monochrome list. The default
is "black".

MenuShadowColor string
This variable specifies the color of the shadow
behind pull-down menus and can only be specified
inside of a Color, Grayscale or Monochrome list.
The default is "black".

MenuTitleBackground string
This variable specifies the background color for
f.title entries in menus, and can only be speci-
fied inside of a Color, Grayscale or Monochrome
list. The default is "white".

MenuTitleForeground string
This variable specifies the foreground color for
f.title entries in menus and can only be specified
inside of a Color or Monochrome list. The default
is "black".

Monochrome { colors }
This variable specifies a list of color assign-
ments that should be made if the screen has a
depth of 1. See the description of Colors.

MoveDelta pixels
This variable specifies the number of pixels the
pointer must move before the f.move function
starts working. Also see the f.deltastop func-
tion. The default is zero pixels.

NoBackingStore
This variable indicates that twm’s menus should
not request backing store to minimize repainting
of menus. This is typically used with servers
that can repaint faster than they can handle back-
ing store.

NoCaseSensitive
This variable indicates that case should be
ignored when sorting icon names in an icon man-
ager. This option is typically used with applica-
tions that capitalize the first letter of their
icon name.

NoDefaults
This variable indicates that twm should not supply
the default titlebuttons and bindings. This
option should only be used if the startup file
contains a completely new set of bindings and def-
initions.

NoGrabServer
This variable indicates that twm should not grab
the server when popping up menus and moving opaque
windows.

NoHighlight [{ win-list }]
This variable indicates that borders should not be
highlighted to track the location of the pointer.
If the optional win-list is given, highlighting
will only be disabled for those windows. When the
border is highlighted, it will be drawn in the
current BorderColor. When the border is not high-
lighted, it will be stippled with a gray pattern
using the current BorderTileForeground and Border-
TileBackground colors.

NoIconManagers
This variable indicates that no icon manager
should be created.

NoMenuShadows
This variable indicates that menus should not have
drop shadows drawn behind them. This is typically
used with slower servers since it speeds up menu
drawing at the expense of making the menu slightly
harder to read.

NoRaiseOnDeiconify
This variable indicates that windows that are
deiconified should not be raised.

NoRaiseOnMove
This variable indicates that windows should not be
raised when moved. This is typically used to
allow windows to slide underneath each other.

NoRaiseOnResize
This variable indicates that windows should not be
raised when resized. This is typically used to
allow windows to be resized underneath each other.

NoRaiseOnWarp
This variable indicates that windows should not be
raised when the pointer is warped into them with
the f.warpto function. If this option is set,
warping to an occluded window may result in the
pointer ending up in the occluding window instead
the desired window (which causes unexpected behav-
ior with f.warpring).

NoSaveUnders
This variable indicates that menus should not
request save-unders to minimize window repainting
following menu selection. It is typically used
with displays that can repaint faster than they
can handle save-unders.

NoStackMode [{ win-list }]
This variable indicates that client window
requests to change stacking order should be
ignored. If the optional win-list is given, only
requests on those windows will be ignored. This
is typically used to prevent applications from
relentlessly popping themselves to the front of
the window stack.

NoTitle [{ win-list }]
This variable indicates that windows should not
have titlebars. If the optional win-list is
given, only those windows will not have titlebars.
MakeTitle may be used with this option to force
titlebars to be put on specific windows.

NoTitleFocus
This variable indicates that twm should not set
keyboard input focus to each window as it is
entered. Normally, twm sets the focus so that
focus and key events from the titlebar and icon
managers are delivered to the application. If the
pointer is moved quickly and twm is slow to
respond, input can be directed to the old window
instead of the new. This option is typically used
to prevent this ‘‘input lag’’ and to work around
bugs in older applications that have problems with
focus events.

NoTitleHighlight [{ win-list }]
This variable indicates that the highlight area of
the titlebar, which is used to indicate the window
that currently has the input focus, should not be
displayed. If the optional win-list is given,
only those windows will not have highlight areas.
This and the SqueezeTitle options can be set to
substantially reduce the amount of screen space
required by titlebars.

OpaqueMove
This variable indicates that the f.move function
should actually move the window instead of just an
outline so that the user can immediately see what
the window will look like in the new position.
This option is typically used on fast displays
(particularly if NoGrabServer is set).

Pixmaps { pixmaps }
This variable specifies a list of pixmaps that
define the appearance of various images. Each
entry is a keyword indicating the pixmap to set,
followed by a string giving the name of the bitmap
file. The following pixmaps may be specified:

Pixmaps
{
TitleHighlight "gray1"
}

The default for TitleHighlight is to use an even
stipple pattern.

Priority priority
This variable sets twm’s priority. priority
should be an unquoted, signed number (e.g. 999).
This variable has an effect only if the server
supports the SYNC extension.

RandomPlacement
This variable indicates that windows with no spec-
ified geometry should be placed in a pseudo-random
location instead of having the user drag out an
outline.

ResizeFont string
This variable specifies the font to be used for in
the dimensions window when resizing windows. The
default is "fixed".

RestartPreviousState
This variable indicates that twm should attempt to
use the WM_STATE property on client windows to
tell which windows should be iconified and which
should be left visible. This is typically used to
try to regenerate the state that the screen was in
before the previous window manager was shutdown.

SaveColor { colors-list }
This variable indicates a list of color assign-
ments to be stored as pixel values in the root
window property _MIT_PRIORITY_COLORS. Clients may
elect to preserve these values when installing
their own colormap. Note that use of this mecha-
nism is a way an for application to avoid the
"technicolor" problem, whereby useful screen
objects such as window borders and titlebars dis-
appear when a programs custom colors are installed
by the window manager. For example:

SaveColor
{
BorderColor
TitleBackground
TitleForeground
"red"
"green"
"blue"
}

This would place on the root window 3 pixel values
for borders and titlebars, as well as the three
color strings, all taken from the default col-
ormap.

ShowIconManager
This variable indicates that the icon manager win-
dow should be displayed when twm is started. It
can always be brought up using the f.showiconmgr
function.

SortIconManager
This variable indicates that entries in the icon
manager should be sorted alphabetically rather
than by simply appending new windows to the end.

SqueezeTitle [{ squeeze-list }]
This variable indicates that twm should attempt to
use the SHAPE extension to make titlebars occupy
only as much screen space as they need, rather
than extending all the way across the top of the
window. The optional squeeze-list may be used to
control the location of the squeezed titlebar
along the top of the window. It contains entries
of the form:

"name" justification num denom

where name is a window name, justification is
either left, center, or right, and num and denom
are numbers specifying a ratio giving the relative
position about which the titlebar is justified.
The ratio is measured from left to right if the
numerator is positive, and right to left if nega-
tive. A denominator of 0 indicates that the
numerator should be measured in pixels. For con-
venience, the ratio 0/0 is the same as 1/2 for
center and -1/1 for right. For example:

SqueezeTitle
{
"XTerm" left 0 0
"xterm1" left 1 3
"xterm2" left 2 3
"oclock" center 0 0
"emacs" right 0 0
}

The DontSqueezeTitle list can be used to turn off
squeezing on certain titles.

StartIconified [{ win-list }]
This variable indicates that client windows should
initially be left as icons until explicitly
deiconified by the user. If the optional win-list
is given, only those windows will be started
iconic. This is useful for programs that do not
support an -iconic command line option or
resource.

TitleBackground string [{ win-list }]
This variable specifies the background color used
in titlebars, and may only be specified inside of
a Color, Grayscale or Monochrome list. The
optional win-list is a list of window names and
colors so that per-window colors may be specified.
The default is "white".

TitleButtonBorderWidth pixels
This variable specifies the width in pixels of the
border surrounding titlebuttons. This is typi-
cally set to 0 to allow titlebuttons to take up as
much space as possible and to not have a border.
The default is 1.

TitleFont string
This variable specifies the font to be used for
displaying window names in titlebars. The default
is "variable".

TitleForeground string [{ win-list }]
This variable specifies the foreground color used
in titlebars, and may only be specified inside of
a Color, Grayscale or Monochrome list. The
optional win-list is a list of window names and
colors so that per-window colors may be specified.
The default is "black".

TitlePadding pixels
This variable specifies the distance between the
various buttons, text, and highlight areas in the
titlebar. The default is 8 pixels.

UnknownIcon string
This variable specifies the filename of a bitmap
file to be used as the default icon. This bitmap
will be used as the icon of all clients which do
not provide an icon bitmap and are not listed in
the Icons list.

UsePPosition string
This variable specifies whether or not twm should
honor program-requested locations (given by the
PPosition flag in the WM_NORMAL_HINTS property) in
the absence of a user-specified position. The
argument string may have one of three values:
"off" (the default) indicating that twm should
ignore the program-supplied position, "on" indi-
cating that the position should be used, and "non-
zero" indicating that the position should used if
it is other than (0,0). The latter option is for
working around a bug in older toolkits.

WarpCursor [{ win-list }]
This variable indicates that the pointer should be
warped into windows when they are deiconified. If
the optional win-list is given, the pointer will
only be warped when those windows are deiconified.

WindowRing { win-list }
This variable specifies a list of windows along
which the f.warpring function cycles.

WarpUnmapped
This variable indicates that the f.warpto function
should deiconify any iconified windows it encoun-
ters. This is typically used to make a key bind-
ing that will pop a particular window (such as
xmh), no matter where it is. The default is for
f.warpto to ignore iconified windows.

XorValue number
This variable specifies the value to use when
drawing window outlines for moving and resizing.
This should be set to a value that will result in
a variety of of distinguishable colors when exclu-
sive-or’ed with the contents of the user’s typical
screen. Setting this variable to 1 often gives
nice results if adjacent colors in the default
colormap are distinct. By default, twm will
attempt to cause temporary lines to appear at the
opposite end of the colormap from the graphics.

Zoom [ count ]
This variable indicates that outlines suggesting
movement of a window to and from its iconified
state should be displayed whenever a window is
iconified or deiconified. The optional count
argument specifies the number of outlines to be
drawn. The default count is 8.

The following variables must be set after the fonts have
been assigned, so it is usually best to put them at the
end of the variables or beginning of the bindings sec-
tions:

DefaultFunction function
This variable specifies the function to be exe-
cuted when a key or button event is received for
which no binding is provided. This is typically
bound to f.nop, f.beep, or a menu containing win-
dow operations.

WindowFunction function
This variable specifies the function to execute
when a window is selected from the TwmWindows
menu. If this variable is not set, the window
will be deiconified and raised.

BINDINGS
After the desired variables have been set, functions may
be attached titlebuttons and key and pointer buttons.
Titlebuttons may be added from the left or right side and
appear in the titlebar from left-to-right according to the
order in which they are specified. Key and pointer button
bindings may be given in any order.

Titlebuttons specifications must include the name of the
pixmap to use in the button box and the function to be
invoked when a pointer button is pressed within them:

LeftTitleButton "bitmapname" = function

or

RightTitleButton "bitmapname" = function

The bitmapname may refer to one of the built-in bitmaps
(which are scaled to match TitleFont) by using the appro-
priate colon-prefixed name described above.

Key and pointer button specifications must give the modi-
fiers that must be pressed, over which parts of the screen
the pointer must be, and what function is to be invoked.
Keys are given as strings containing the appropriate
keysym name; buttons are given as the keywords But-
ton1-Button5:

"FP1" = modlist : context : function
Button1 = modlist : context : function

The modlist is any combination of the modifier names
shift, control, lock, meta, mod1, mod2, mod3, mod4, or
mod5 (which may be abbreviated as s, c, l, m, m1, m2, m3,
m4, m5, respectively) separated by a vertical bar (|).
Similarly, the context is any combination of window,
title, icon, root, frame, iconmgr, their first letters
(iconmgr abbreviation is m), or all, separated by a verti-
cal bar. The function is any of the f. keywords
described below. For example, the default startup file
contains the following bindings:

Button1 = : root : f.menu "TwmWindows"
Button1 = m : window | icon : f.function "move-or-lower"
Button2 = m : window | icon : f.iconify
Button3 = m : window | icon : f.function "move-or-raise"
Button1 = : title : f.function "move-or-raise"
Button2 = : title : f.raiselower
Button1 = : icon : f.function "move-or-iconify"
Button2 = : icon : f.iconify
Button1 = : iconmgr : f.iconify
Button2 = : iconmgr : f.iconify

A user who wanted to be able to manipulate windows from
the keyboard could use the following bindings:

"F1" = : all : f.iconify
"F2" = : all : f.raiselower
"F3" = : all : f.warpring "next"
"F4" = : all : f.warpto "xmh"
"F5" = : all : f.warpto "emacs"
"F6" = : all : f.colormap "next"
"F7" = : all : f.colormap "default"
"F20" = : all : f.warptoscreen "next"
"Left" = m : all : f.backiconmgr
"Right" = m | s : all : f.forwiconmgr
"Up" = m : all : f.upiconmgr
"Down" = m | s : all : f.downiconmgr

Twm provides many more window manipulation primitives than
can be conveniently stored in a titlebar, menu, or set of
key bindings. Although a small set of defaults are sup-
plied (unless the NoDefaults is specified), most users
will want to have their most common operations bound to
key and button strokes. To do this, twm associates names
with each of the primitives and provides user-defined
functions for building higher level primitives and menus
for interactively selecting among groups of functions.

User-defined functions contain the name by which they are
referenced in calls to f.function and a list of other
functions to execute. For example:

Function "move-or-lower" { f.move f.deltastop f.lower }
Function "move-or-raise" { f.move f.deltastop f.raise }
Function "move-or-iconify" { f.move f.deltastop f.iconify }
Function "restore-colormap" { f.colormap "default" f.lower }

The function name must be used in f.function exactly as it
appears in the function specification.

In the descriptions below, if the function is said to
operate on the selected window, but is invoked from a root
menu, the cursor will be changed to the Select cursor and
the next window to receive a button press will be chosen:

! string
This is an abbreviation for f.exec string.

f.autoraise
This function toggles whether or not the selected
window is raised whenever entered by the pointer.
See the description of the variable AutoRaise.

f.backiconmgr
This function warps the pointer to the previous
column in the current icon manager, wrapping back
to the previous row if necessary.

f.beep This function sounds the keyboard bell.

f.bottomzoom
This function is similar to the f.fullzoom func-
tion, but resizes the window to fill only the bot-
tom half of the screen.

f.circledown
This function lowers the top-most window that
occludes another window.

f.circleup
This function raises the bottom-most window that
is occluded by another window.

f.colormap string
This function rotates the colormaps (obtained from
the WM_COLORMAP_WINDOWS property on the window)
that twm will display when the pointer is in this
window. The argument string may have one of the
following values: "next", "prev", and "default".
It should be noted here that in general, the
installed colormap is determined by keyboard
focus. A pointer driven keyboard focus will
install a private colormap upon entry of the win-
dow owning the colormap. Using the click to type
model, private colormaps will not be installed
until the user presses a mouse button on the tar-
get window.

f.deiconify
This function deiconifies the selected window. If
the window is not an icon, this function does
nothing.

f.delete
This function sends the WM_DELETE_WINDOW message
to the selected window if the client application
has requested it through the WM_PROTOCOLS window
property. The application is supposed to respond
to the message by removing the indicated window.
If the window has not requested WM_DELETE_WINDOW
messages, the keyboard bell will be rung indicat-
ing that the user should choose an alternative
method. Note this is very different from
f.destroy. The intent here is to delete a single
window, not necessarily the entire application.

f.deltastop
This function allows a user-defined function to be
aborted if the pointer has been moved more than
MoveDelta pixels. See the example definition
given for Function "move-or-raise" at the begin-
ning of the section.

f.destroy
This function instructs the X server to close the
display connection of the client that created the
selected window. This should only be used as a
last resort for shutting down runaway clients.
See also f.delete.

f.downiconmgr
This function warps the pointer to the next row in
the current icon manger, wrapping to the beginning
of the next column if necessary.

f.exec string
This function passes the argument string to
/bin/sh for execution. In multiscreen mode, if
string starts a new X client without giving a dis-
play argument, the client will appear on the
screen from which this function was invoked.

f.focus This function toggles the keyboard focus of the
server to the selected window, changing the focus
rule from pointer-driven if necessary. If the
selected window already was focused, this function
executes an f.unfocus.

f.forcemove
This function is like f.move except that it
ignores the DontMoveOff variable.

f.forwiconmgr
This function warps the pointer to the next column
in the current icon manager, wrapping to the
beginning of the next row if necessary.

f.fullzoom
This function resizes the selected window to the
full size of the display or else restores the
original size if the window was already zoomed.

f.function string
This function executes the user-defined function
whose name is specified by the argument string.

f.hbzoom
This function is a synonym for f.bottomzoom.

f.hideiconmgr
This function unmaps the current icon manager.

f.horizoom
This variable is similar to the f.zoom function
except that the selected window is resized to the
full width of the display.

f.htzoom
This function is a synonym for f.topzoom.

f.hzoom This function is a synonym for f.horizoom.

f.iconify
This function iconifies or deiconifies the
selected window or icon, respectively.

f.identify
This function displays a summary of the name and
geometry of the selected window. If the server
supports the SYNC extension, the priority of the
client owning the window is also displayed.
Clicking the pointer or pressing a key in the win-
dow will dismiss it.

f.lefticonmgr
This function similar to f.backiconmgr except that
wrapping does not change rows.

f.leftzoom
This variable is similar to the f.bottomzoom func-
tion but causes the selected window is only
resized to the left half of the display.

f.lower This function lowers the selected window.

f.menu string
This function invokes the menu specified by the
argument string. Cascaded menus may be built by
nesting calls to f.menu.

f.move This function drags an outline of the selected
window (or the window itself if the OpaqueMove
variable is set) until the invoking pointer button
is released. Double clicking within the number of
milliseconds given by ConstrainedMoveTime warps
the pointer to the center of the window and con-
strains the move to be either horizontal or verti-
cal depending on which grid line is crossed. To
abort a move, press another button before releas-
ing the first button.

f.nexticonmgr
This function warps the pointer to the next icon
manager containing any windows on the current or
any succeeding screen.

f.nop This function does nothing and is typically used
with the DefaultFunction or WindowFunction vari-
ables or to introduce blank lines in menus.

f.previconmgr
This function warps the pointer to the previous
icon manager containing any windows on the current
or preceding screens.

f.priority string
This function sets the priority of the client own-
ing the selected window to the numeric value of
the argument string, which should be a signed
integer in double quotes (e.g. "999" ). This
function has an effect only if the server supports
the SYNC extension.

f.quit This function causes twm to restore the window’s
borders and exit. If twm is the first client
invoked from xdm, this will result in a server
reset.

f.raise This function raises the selected window.

f.raiselower
This function raises the selected window to the
top of the stacking order if it is occluded by any
windows, otherwise the window will be lowered.

f.refresh
This function causes all windows to be refreshed.

f.resize
This function displays an outline of the selected
window. Crossing a border (or setting AutoRela-
tiveResize) will cause the outline to begin to
rubber band until the invoking button is released.
To abort a resize, press another button before
releasing the first button.

f.restart

This function kills and restarts twm.

f.righticonmgr
This function is similar to f.nexticonmgr except
that wrapping does not change rows.

f.rightzoom
This variable is similar to the f.bottomzoom func-
tion except that the selected window is only
resized to the right half of the display.

f.saveyourself
This function sends a WM_SAVEYOURSELF message to
the selected window if it has requested the mes-
sage in its WM_PROTOCOLS window property. Clients
that accept this message are supposed to check-
point all state associated with the window and
update the WM_COMMAND property as specified in the
ICCCM. If the selected window has not selected
for this message, the keyboard bell will be rung.

f.showiconmgr
This function maps the current icon manager.

f.sorticonmgr
This function sorts the entries in the current
icon manager alphabetically. See the variable
SortIconManager.

f.title This function provides a centered, unselectable
item in a menu definition. It should not be used
in any other context.

f.topzoom
This variable is similar to the f.bottomzoom func-
tion except that the selected window is only
resized to the top half of the display.

f.unfocus
This function resets the focus back to pointer-
driven. This should be used when a focused window
is no longer desired.

f.upiconmgr
This function warps the pointer to the previous
row in the current icon manager, wrapping to the
last row in the same column if necessary.

f.vlzoom
This function is a synonym for f.leftzoom.

f.vrzoom
This function is a synonym for f.rightzoom.

f.warpring string
This function warps the pointer to the next or
previous window (as indicated by the argument
string, which may be "next" or "prev") specified
in the WindowRing variable.

f.warpto string
This function warps the pointer to the window
which has a name or class that matches string. If
the window is iconified, it will be deiconified if
the variable WarpUnmapped is set or else ignored.

f.warptoiconmgr string
This function warps the pointer to the icon man-
ager entry associated with the window containing
the pointer in the icon manager specified by the
argument string. If string is empty (i.e. ""),
the current icon manager is chosen.

f.warptoscreen string
This function warps the pointer to the screen
specified by the argument string. String may be a
number (e.g. "0" or "1"), the word "next" (indi-
cating the current screen plus 1, skipping over
any unmanaged screens), the word "back" (indicat-
ing the current screen minus 1, skipping over any
unmanaged screens), or the word "prev" (indicating
the last screen visited.

f.winrefresh
This function is similar to the f.refresh function
except that only the selected window is refreshed.

f.zoom This function is similar to the f.fullzoom func-
tion, except that the only the height of the
selected window is changed.

MENUS
Functions may be grouped and interactively selected using
pop-up (when bound to a pointer button) or pull-down (when
associated with a titlebutton) menus. Each menu specifi-
cation contains the name of the menu as it will be
referred to by f.menu, optional default foreground and
background colors, the list of item names and the func-
tions they should invoke, and optional foreground and
background colors for individual items:

Menu "menuname" [ ("deffore":"defback") ]
{
string1 [ ("fore1":"backn")] function1
string2 [ ("fore2":"backn")] function2
.
.
.
stringN [ ("foreN":"backN")] functionN
}

The menuname is case-sensitive. The optional deffore and
defback arguments specify the foreground and background
colors used on a color display to highlight menu entries.
The string portion of each menu entry will be the text
which will appear in the menu. The optional fore and back
arguments specify the foreground and background colors of
the menu entry when the pointer is not in the entry.
These colors will only be used on a color display. The
default is to use the colors specified by the MenuFore-
ground and MenuBackground variables. The function portion
of the menu entry is one of the functions, including any
user-defined functions, or additional menus.

There is a special menu named TwmWindows which contains
the names of all of the client and twm-supplied windows.
Selecting an entry will cause the WindowFunction to be
executed on that window. If WindowFunction hasn’t been
set, the window will be deiconified and raised.

ICONS
Twm supports several different ways of manipulating iconi-
fied windows. The common pixmap-and-text style may be
laid out by hand or automatically arranged as described by
the IconRegion variable. In addition, a terse grid of
icon names, called an icon manager, provides a more effi-
cient use of screen space as well as the ability to navi-
gate among windows from the keyboard.

An icon manager is a window that contains names of
selected or all windows currently on the display. In
addition to the window name, a small button using the
default iconify symbol will be displayed to the left of
the name when the window is iconified. By default, click-
ing on an entry in the icon manager performs f.iconify.
To change the actions taken in the icon manager, use the
the iconmgr context when specifying button and keyboard
bindings.

Moving the pointer into the icon manager also directs key-
board focus to the indicated window (setting the focus
explicitly or else sending synthetic events NoTitleFocus
is set). Using the f.upiconmgr, f.downiconmgr
f.lefticonmgr, and f.righticonmgr functions, the input
focus can be changed between windows directly from the
keyboard.

BUGS
The resource manager should have been used instead of all
of the window lists.

The IconRegion variable should take a list.

Double clicking very fast to get the constrained move
function will sometimes cause the window to move, even
though the pointer is not moved.

If IconifyByUnmapping is on and windows are listed in
IconManagerDontShow but not in DontIconifyByUnmapping,
they may be lost if they are iconified and no bindings to
f.menu "TwmWindows" or f.warpto are setup.

FILES
$HOME/.twmrc.<screen number>
$HOME/.twmrc
<XRoot>/lib/X11/twm/system.twmrc

ENVIRONMENT VARIABLES
DISPLAY This variable is used to determine which X server
to use. It is also set during f.exec so that pro-
grams come up on the proper screen.

HOME This variable is used as the prefix for files that
begin with a tilde and for locating the twm
startup file.

SEE ALSO
X(1), Xserver(1), xdm(1), xrdb(1)

AUTHORS
Tom LaStrange, Solbourne Computer; Jim Fulton, MIT X Con-
sortium; Steve Pitschke, Stardent Computer; Keith Packard,
MIT X Consortium; Dave Sternlicht, MIT X Consortium; Dave
Payne, Apple Computer.

X Version 11 Release 6 24