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Full Discussion: Writing to a Serial Port
Top Forums Web Development Writing to a Serial Port Post 302921695 by neutronscott on Sunday 19th of October 2014 05:31:12 PM
Old 10-19-2014
This is not reading from the port. You cannot do 2 redirections. You're attaching stdout to /dev/ttyS0 but immediately changing that to a file called bla.

Code:
mute@thedoctor:~$ echo hi >file1 >file2
mute@thedoctor:~$ ls -l file?
-rw-r--r-- 1 mute mute 0 Oct 19 21:29 file1
-rw-r--r-- 1 mute mute 3 Oct 19 21:29 file2

This shows how redirection to two places fails. You only need to:
Code:
$ echo W >/dev/ttyS0
$ cat /dev/ttyS0

Try to set permissions, as root, to allow everyone access to the serial port with chmod 0666 /dev/ttyS0. If your code then works, the issue is that the webserver doesn't run as ethan, but another user who doesn't have access to ttyS0.
 

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MIXERCTL.CONF(5)					      BSD File Formats Manual						  MIXERCTL.CONF(5)

NAME
mixerctl.conf -- audio mixer configuration file SYNOPSIS
mixerctl.conf DESCRIPTION
The /etc/mixerctl.conf file consists of mixerctl(1) variables to set at boot time. Each line of mixerctl.conf has the following format: variable=value To generate a mixerctl.conf from the current mixer settings, execute: mixerctl -a > /etc/mixerctl.conf Set mixerctl to YES in rc.conf(5) to have the variables set at boot time. Additionally, you can have the settings saved and restored for the devices of your choice by listing them in mixerctl_mixers in rc.conf(5). FILES
/etc/mixerctl.conf EXAMPLES
Example mixer settings for an esa(4) audio adapter: outputs.master=255,255 outputs.master.mute=off outputs.mono=255 outputs.mono.mute=on outputs.mono.source=mixerout outputs.headphones=255,255 outputs.headphones.mute=off outputs.tone=255,255 inputs.speaker=255 inputs.speaker.mute=off inputs.phone=191 inputs.phone.mute=on inputs.mic=191 inputs.mic.mute=on inputs.mic.preamp=off inputs.mic.source=mic0 inputs.line=191,191 inputs.line.mute=on inputs.cd=191,191 inputs.cd.mute=on inputs.video=255,255 inputs.video.mute=off inputs.aux=255,255 inputs.aux.mute=off inputs.dac=191,191 inputs.dac.mute=off record.source=mic record.volume=255,255 record.volume.mute=off record.mic=0 record.mic.mute=off outputs.loudness=off outputs.spatial=off outputs.spatial.center=0 outputs.spatial.depth=0 SEE ALSO
mixerctl(1), rc.conf(5) HISTORY
The mixerctl.conf configuration file first appeared in NetBSD 2.0. BSD
April 5, 2003 BSD
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