Crontab is not working on Raspberry Pi 4

Question

here my system info:

$ uname -a
Linux rp4 6.6.51+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.6.51-1+rpt1 (2024-09-26) aarch64 GNU/Linux

All these lines are working directly from command line on RPi4.

18 21 * * * /usr/bin/play /home/user/1.mp3 >/dev/null 2>&1
19 21 * * * /usr/bin/play /home/user/1.mp3
20 21 * * * sh /home/user/playlist.sh

Here is the executable script playlist.sh:

#!/usr/bin/env bash

/usr/bin/play "/home/user/5.m3u"

This one is working

30 21 * * * touch test.txt

What do I do wrong? Thank you :)

goldilocks U DA MAN! By using your hint to redirect the output to a file (I am so stupid not to think about it my self). I got these 3 lines in the file:

couldn't open play stream: Unknown error 524 /usr/bin/play FAIL ao: Could not find a default ao driver /usr/bin/play FAIL sox: Sorry, there is no default audio device configured

By using aplay -l I found my default device. Which is bcm2835 Headphones

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones]
  Subdevices: 8/8

Here I found how to set a default device with SOX: https://linux.die.net/man/1/sox

set AUDIODEV=hw:2 in my case export AUDIODEV=hw:2

Here is my final script:

#!/usr/bin/env bash

export AUDIODEV=hw:2

/usr/bin/play "/home/user/5.m3u"

Answer 1

Chances are cron is working, it's the command that's not -- because it does not automatically have access to the sound system when run this way.

Instead of discarding any possible output, you should write it to a file somewhere in case there's an informative error, etc.:

18 21 * * * /usr/bin/play /home/user/1.mp3 >/var/log/cron-play.txt 2>&1

If that's a user cron tab (and not the system one), you'll want a different log path since that requires root privilleges. /tmp is a good place for that since anyone can use it, but it all gets deleted on reboot.