How can I get know when I plug my headphones into the 3.5 interface?

Question

I want to write a small program in C: When I plug my headphones in my notebook, it should turn the volume lower. Then, when I remove headphone from my notebook, it should turn the volume back up.

I am using the alsa driver, and I know how to control the volume.

The question is: How to get notified, when the headphone gets plugged in?

Before I asked this question, I tried to use IRQ. I used watch -d0.5 cat /proc/stat to see if any interrupts are experienced by the system when I plug in or remove my headphone, and I see 8 interrupts. I don't know with IRQ is the right one so, I have no idea.

@BasileStarynkevitch , thanks, I have heared about it. So I add it as a tag. But I don't konw how to use it. Could you please give me some information about it? Thank you again. :) — madper, Apr 26 '12 at 08:19
http://linux.die.net/man/8/udev http://en.wikipedia.org/wiki/Udev http://www.reactivated.net/writing_udev_rules.html — Basile Starynkevitch, Apr 26 '12 at 09:09
Madper if you get to solve your problem, post what you did as an answer and mark it as such. This is allowed in SO. — RedX, Apr 26 '12 at 11:12

score 0 · Accepted Answer · answered May 05 '12 at 17:15

0

Maybe you don't need to write any program. Alsamixer should let you specify the volume of the speaker and the volume of the headphones. You just set the headphones' volume a little lower, and that's all.

answered May 05 '12 at 17:15

Cojocaru Alexandru

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How can I get know when I plug my headphones into the 3.5 interface?

1 Answers1