screenrc: Display current battery charge.

Also add battery.pl script and update setup.sh to only enable it if
necessary.

diff --git a/bin/battery.pl b/bin/battery.pl
new file mode 100755 (executable)
index 0000000..31501ac
--- /dev/null
+++ b/bin/battery.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+
+
+use strict;
+use warnings;
+
+
+my $path = '/sys/class/power_supply/BAT0/uevent';
+
+# No battery available.
+if (! -e $path) {
+    exit;
+}
+
+my $screen_mode = (defined $ARGV[0] and $ARGV[0] eq '-s');
+
+my %battery;
+
+open my $file, '<', $path;
+while (<$file>) {
+    /^POWER_SUPPLY_([A-Z_]+)=(.+)$/;
+    $battery{$1} = $2;
+}
+close $file;
+
+my $charge = int($battery{CHARGE_NOW} / $battery{CHARGE_FULL} * 100);
+
+# GNU screen mode with colors: 0-20 red, 20-40 yellow, 40-100 green.
+if ($screen_mode) {
+    my $color;
+    if ($charge < 20) {
+        $color = 'b r';
+    } elsif ($charge < 40) {
+        $color = 'b y';
+    } else {
+        $color = 'b g';
+    }
+
+    print "\005{+$color}$charge%\005{-}\n";
+
+# Just text output.
+} else {
+    print "$charge%\n";
+}

diff --git a/screenrc.in b/screenrc.in
index 02212fb20ef3472d9b38b27b13bd5ac3daa562c7..37d61da70fcff39640bcab3ee8a84d53a943f173 100644 (file)
--- a/screenrc.in
+++ b/screenrc.in
@@ -37,6 +37,10 @@ attrcolor b ".I"
 # for window borders in split mode).
 sorendition = Bw
 
+# Display current battery charge if running on a laptop. Redisplay every 3
+# minutes.
+backtick 1 180 180 $HOME/.shell/bin/battery.pl -s # (BATTERY)
+
 # Make sure the temporary variable we use is empty. Thanks to
 # http://gist.github.com/133000 for the idea to use setenv and to TauPan in
 # #screen on Freenode (2010-03-10 16:11 CET) for reminding me of it and
@@ -61,6 +65,8 @@ setenv s "$s%="  # - right align the following text
 setenv s "$s%l"  # - load average
 setenv s "$s "   # - space
 setenv s "$s%H"  # - hostname
+setenv s "$s "   # - space          (BATTERY)
+setenv s "$s%1`" # - battery status (BATTERY)
 hardstatus alwayslastline "$s"
 unsetenv s
 

diff --git a/setup.sh b/setup.sh
index a7ae8fd2a52d5899b49b15c45b579458817f2936..ec6f9d749364a2f4f8c84d086561e911974f2da4 100755 (executable)
--- a/setup.sh
+++ b/setup.sh
@@ -33,6 +33,13 @@ if installed rxvt; then
     sed 's/attrcolor b ".I"/#attrcolor b ".I"/' screenrc > screenrc.tmp
     mv screenrc.tmp screenrc
 fi
+# Display current battery charge on computers with a battery. Necessary lines
+# are marked as "(BATTERY)".
+if [ ! -d /sys/class/power_supply/BAT0 ]; then
+    echo screenrc: removing battery display
+    grep -v '(BATTERY)' screenrc > screenrc.tmp
+    mv screenrc.tmp screenrc
+fi
 
 # Link setup for shells.
 link shell ~/.shell