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alttab - the task switcher


alttab [-w N] [-d N] [-sc N] [-mk str] [-kk str] [-bk str] [-mm N] [-bm N] [-t NxM] [-i NxM] [-vp str] [-p str] [-s N] [-theme name] [-bg color] [-fg color] [-frame color] [-font name] [-v|-vv]


The task switcher designed for minimalistic window managers or standalone X11 session.

Unlike task switchers integrated in most simple WMs, alttab features visual interface and convenient tactile behaviour, switching windows on releasing Alt key.

Being lightweight and depending only on core X11 libs, it still features customizable look and behaviour.


Most command line options have corresponding X resource, see doc/ for example.

resource: alttab.windowmanager
default: autodetect, fallback to 3
Control how to obtain window list and set focus. NUMBER must be between 0 and 3:
0: No WM, raw X.
Set this value manually, as it´s not autodetected. Only top-level viewable children of root window are listed. Running -w 0 under WM is discouraged: hidden windows or windows on another desktops will not be listed; instead, some strange windows may be included.
1: EWMH compatible.
Compatible WM list is in [SEE ALSO] below. alttab functions in xmonad (EWMH must be allowed, details in doc/, i3, evilwm, xfwm4, metacity, jwm, openbox, fluxbox, icewm, enlightenment, blackbox, aewm, fvwm, sawfish. The following WMs support EWMH partially but work in -w 1 mode too: dwm (issue #9), matchbox (issue #34), windowmaker (issue #9), xpra (issue #37), cwm (issue #35), ctwm (issue #39), lwm (issue #40), awesome (issue #41).
2: Ratpoison.
Alttab uses ratpoison own remote control capability. Additionally, alttab registers itself in its "unmanaged list" automatically.
3: Ancient WM.
Fallback, worse than 0. Search for application windows at random nodes of window tree (WM is probably reparenting) and select only those with a name, including non-viewable (WM is probably iconifying). May cause lag. Tested in twm, flwm, wm2.
resource: alttab.desktops
default: 0
Show windows belonging to desktops (workspaces, groups). NUMBER must be between 0 and 3:
0: Current desktop.
This is default, although in non EWMH-compatible WM, except ratpoison, it´s effectively the same as 1.
1: All desktops.
2: All desktops, excluding special (-1) one.
In various EWMH WM this desktop may be designed hidden or containing sticky windows. In i3, it´s "scratchpad".
3: All desktops, excluding current and special.
resource: alttab.screens
default: 1
Show windows belonging to xrandr/xinerama screens. NUMBER must be 0 or 1:
0: Current screen.
As defined according to -vp pointer or -vp focus.
1: All screens.
This is default.
resource: alttab.modifier.keysym
default: Alt_L
Keysym of main modifier. String or number accepted. Suitable examples: Control_L, Super_L.
resource: alttab.key.keysym
default: Tab
Keysym of main key. For example, grave (aka tilde), Escape.
resource: alttab.backscroll.keysym
default: any Shift, according to ShiftMask
Keysym of backward scroll key.
resource: alttab.modifier.mask
OBSOLETED, guessed from -mk instead.
resource: alttab.backscroll.mask
OBSOLETED, guessed from -bk instead.
resource: alttab.tile.geometry
default: 112x128
Size of a single tile (mini-window). If switcher doesn´t fit the viewport (-vp), tile may be thinner.
resource: alttab.icon.geometry
default: 32x32
Size of icons.
resource: alttab.viewport
default: focus
Limit viewport for the switcher. The switcher always has variable size and position, but tries to never break out of -vp container, while -p specifies position relative to this container. Together these options allow for WM-independent multi-monitor support. Possible values for -vp:
focus: in multihead configuration: the monitor which shows largest part of currently focused window. If this part is shared with other monitors, then the smallest of these monitors is choosen. In single head configuration: the geometry of default root window.
pointer: the monitor which has mouse pointer, otherwise the same as focus.
The "multihead" above means more than one active XRANDR output. They are detected at runtime, so hopefully monitors may be attached/detached without restarting alttab.
total: the geometry of default root window.
If you specify this in tiling multihead configuration, then the switcher will be drawn relative to the entire combined screen, crossing monitors´ borders.
WxH+X+Y: Specific position relative to default root window.
This allows for static manual bounding if XRANDR detection fails. Suppose X root window spans over two 2560х1440 monitors, resulting in combined screen of 5120x1440 size. Then the switcher may be positioned at the center of the right monitor with -vp 2560x1440+2560+0 -p center.
resource: alttab.position
default: center
Position of switcher: "center", "none" or specific position relative to upper left corner of viewport, in the form +X+Y.
resource: alttab.icon.source
default: 2
Source of icons. NUMBER must be between 0 and 3:
0: Use icons from X11 window attributes only.
1: Load icon from file if not found in window attributes.
Alttab searches for PNG icons under:
Directory structure should obey freedesktop standard, but desktop files are ignored, instead file name is expected to be equal to application class. That is, if alttab doesn´t recognize an icon for window of class foo, as obtained by ´xprop WM_CLASS´, then just drop a 32x32 icon into /usr/local/share/icons/hicolor/32x32/apps/foo.png.
2: Prefer icon from file when it matches requested size better (see -i option).
3: Use icons from files only.
resource: alttab.theme
default: hicolor
Desktop theme for application icons. Used when -s is 1, 2 or 3.

The following three options accept color names or #rrggbb. Special value _rnd_low or _rnd_high produce random color from lower or upper RGB space respectively.

resource: alttab.background
default: black
Tile background color.
resource: alttab.foreground
default: grey
Foreground color.
resource: alttab.framecolor
default: #a0abab
Color of frame around selected tile.
resource: alttab.font
default: xft:sans-10
Label font name in format: xft:fontconfig_pattern, like in emacs and rxvt. See [SEE ALSO] for fontconfig pattern. It´s neither GTK font pattern nor legacy XLFD.

Your Xresources database probably already has *background, *foreground or *font wildcard definitions, which alttab will obey. Precedence order (preferred first):

alttab.font resource,
-font option,
wildcard resource like *font in xfd: format.

resource: no
default: silent
short help


Run alttab after WM, or autodetection will fail.


Copyright 2017-2019 Alexander Kulak <sa-dev AT odd POINT systems>.


Please report issues on github



EWMH compatible WM list

Description of fontconfig pattern

April 2019