Battery vs. AC for a shell script?

I'd like to write a shell script to do stuff only if I'm on AC and not running just on battery power. I checked dcop, I thought there might be something in klaptop, but there was nothing. I thought there might be something I could use in /proc but I got lost really quickly. Searches were all too general.

Has anyone ever written a shell script that has to do with this?

If anyone's wondering, I want to make a cronjob to start setiathome every night, but only if I'm plugged into the wall. I don't need to kill my battery looking for aliens ;)

Use perl or grep to parse the output of 'apm'.

Eg. it usually outputs something like:

Code:

---

AC on-line, battery status high: 99% (3:27)

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So, a simple:

Code:

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if [ `/usr/bin/apm | grep -c "AC\ on-line"` -eq "1" ]; then
    search_for_little_green_men &
fi

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... should do the trick.

With the 2.4 and 2.6 kernels it is /proc/acpi/ac_adapter/AC/state and the two states it is in is

Code:

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state:                      on-line
state:                      off-line

---

in the cron job you can cat and grep the status and use that to determine to run SETI or not

cat /proc/acpi/ac_adapter/AC/state | cut -c26-32

For me that will show the state of on-line or off-line (test with yours to verify)

I'll let you figure out the if/then statement to use :)

Absolutely perfect! Thanks guys!