Here is a small app which sits on the root window and displays a bar graph and numerical percentage. The default display is my usage: displaying percentage of swap space used on FreeBSD.
#!/bin/sh
# \
exec wish "$0" -- "$@"
set orient h
set geom 150x25+[expr {[winfo vrootwidth .] - 150}]+[expr {[winfo vrootheight .] - 25}]
array set colors "0 white"
set interval 5000
set command {[string trimright [lindex [exec pstat -s] 10] %]}
set from 0
set to 100
set background black
set foreground white
set label 1
set font ""
proc ref {} {
global tag rect orient interval command to from geom
eval set data $command
if {$orient == "h"} {set w [winfo width .c]} elseif {$orient == "v"} {set w [winfo height .c]}
set size [expr ($data - $from.00) / ($to.00 - $from.00)]
set per [expr {round($size * 100)}]
set size [expr $size * $w.00]
.l configure -text ${per}%
.c itemconfigure $tag -fill [getcolor $per]
eval .c coords $tag $rect
after $interval ref
}
proc getcolor {num} {
global colors colorn
foreach x $colorn {
if {$x <= $num} {break}
set ret $x
}
return $colors($x)
}
proc ParseCommandline { } {
global argv argc
set num 0
while {[set tmp [lrange $argv $num end]] != ""} {
switch -glob -- [lindex $tmp 0] {
-geometry {
global geom
set geom [lindex $tmp 1]
incr num 2
}
-colors {
global colors
array set colors [lindex $tmp 1]
incr num 2
}
-orient {
global orient
set orient [lindex $tmp 1]
incr num 2
}
-from {
global from
set from [lindex $tmp 1]
incr num 2
}
-to {
global to
set to [lindex $tmp 1]
incr num 2
}
-foreground {
global foreground
set foreground [lindex $tmp 1]
incr num 2
}
-background {
global background
set background [lindex $tmp 1]
incr num 2
}
-command {
global command
eval set command \"[lindex $tmp 1]\"
incr num 2
}
-interval {
global interval
set interval [lindex $tmp 1]
incr num 2
}
-label {
global label
set label 0
incr num 1
}
-font {
global font
set font [lindex $tmp 1]
incr num 2
}
-* {
puts stderr "Unknown option [lindex $tmp 0]"
exit
}
default {
puts stderr "Too many arguments"
exit
}
}
}
}
ParseCommandline
wm withdraw .
. configure -borderwidth 0 -highlightthickness 0 -takefocus 0 -background ""
wm title . xswapinfo
wm geometry . $geom
wm overrideredirect . 1
update idletasks
canvas .c -bg $background -borderwidth 0 -highlightthickness 0
label .l -bg $background -fg $foreground -text 0%
if {$font != ""} {
.l configure -font $font
}
if {$orient == "h"} {
if $label {pack .l -side left -fill both}
pack .c -side right -expand 1 -fill both
set rect "-1 -1 \$size \[winfo height .c\]"
} elseif {$orient == "v"} {
if $label {pack .l -side bottom -fill both}
pack .c -side top -expand 1 -fill both
set rect "-1 \[winfo height .c\] \[winfo width .c\] \[expr \[winfo height .c\] - \$size\]"
}
set colorn [lsort -integer -decreasing [array names colors]]
set size 0
update idletasks
wm deiconify .
set tag [eval .c create rectangle $rect]
ref