Samsung Galaxy S2 i9100 over-heating battery symbol fix (Probably water related)

It turns out that phones don’t like water (even rain). After a particularly heavy rain shower, my phone developed a strange behavior where it would show a battery symbol together with a hot thermometer and refuse to switch on. This fixed itself after 10 minutes or so, but some time later the similar symptoms reappeared.

• The phone ran fine when on
• When switched off the phone refused to switch on (with aforementioned over-heating battery symbol)
• However, when the micro-usb had a power source plugged in everything worked fine.

It seems like this is a common problem with the usb connector, and some people have fixed similar issues by buying replacement usb cards. Fortunately, I didn’t need to go so far, blowing compressed air into the micro-usb connector completely fixed this issue.

Ensure a bash process tidies up its children

When you have a bash process that spawns a number of background children, there is an unforunate side effect: These processes never exit. If you try to kill their parent they are happilly adopted by init.

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Code

Adding the following line at the beginning of your bash script ensure that all your children are truly dead when you yourself are killed.

trap "kill -- -$BASHPID" EXIT

The -PID argument tells bash to kill the process group with id $BASHPID, process groups have the same id as the spawning process (but the process group id remains even after processes have been reparented). The — gets kill not to interpret this as a signal :S.

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Caveats

The one caveat here is if someone sends you kill -9. If this happens, you don’t get to do anything before your imminent death (even murder all your children).