Recording using arecord creates thousands of files

Question

I was trying to use arecord to record a wav file, but instead of recording to one file, it created tens of thousands of files (around 60000). This happened after I had installed the alsaequal package. I used to record using the -f dat flag with arecord, but after I installed alsaequal, this stopped working so I tried to use -f cd, which is when this problem occured. I don't know if it is alsaequal that is causing this behavior or the use of the cd format. I am using Arch Linux on a Raspberry Pi. The full command that I ran was arecord -f cd test.wav and the files it outputted were all named test-xxxxx.wav Does anyone have any idea what might be causing this problem?

Update: This seems to happen randomly. It will work fine for a bunch of recordings and then I restart or run arecord with slightly different arguments, which will cause the problem to occur each time I record (no matter what arguments I use). I haven't been able to find a reproducible pattern.

Answer 1

It appears that when arecord receives a SIGINT it gets upset and creates thousands of files. (This will happen if you Ctrl-C whilst it is recording.) I'm not sure how to "fix" it (I'd classify it as a bug, anyway), but I will offer two workarounds:

1. Don't SIGINT, just SIGKILL (killall -KILL arecord)

2. To prevent thousands of files being created do the following instead:

   arecord - > /tmp/sample.wav 2> /dev/null

   Now, instead of producing sample-1.wav, sample-2.wav, etc, arecord sends all it's data to STDOUT, which you redirect to a file of your choice. Messages are printed to STDERR which is redirected to /dev/null in this case. The tradeoff is that instead of thousands of files being created, that single file will grow very large - which may or may not be considered as an improvement!

As a bonus gift; since the classic "rm /tmp/sample*.wav" is likely to report "too many files"; here is how to clean up the mess (adjust as appropriate):

find /tmp -type f -name sample*.wav -exec rm {} \+

Just for the record:

$ arecord --version
arecord version 1.0.27 by Jaroslav Kysela <[e-mail]>