[mythtv-users] External Channel Change Question? - WAS Re: CentOS and MythTV

[Len Reed]

Kenneth Hadley wrote:
> Brian Wood wrote:
> 
>>On Feb 12, 2006, at 7:02 PM, Kenneth Hadley wrote:
>>
>>  
>>
>>>Appears I spoke too soon about have no further problems.
>>>
>>>I use a MyBlaster to control my external Samsung DirecTV receiver and
>>>with my previous box this worked fine using the MyBlaster.pl script.
>>>
>>>This time...not working so well.
>>>
>>>I have the script located in /usr/local/bin/ and typed into the input
>>>field of "mythtvsetup=>input connections=>/dev/video0/=>External  
>>>channel
>>>change command" the script path/filename (/usr/local/bin/MyBlaster.pl)
>>>but when I record programs the channel never changes and when watching
>>>the MyBlaster transmitter when the recording starts and it should be
>>>blinking, it does not.
>>>
>>>Manually typing at the CLI
>>>[mythtv at pvr01 ~]$ /usr/local/bin/MyBlaster.pl 298
>>>Does change the channel.
>>>
>>>Anyone have any thoughts?
>>>
>>>Thanks!
>>>    
>>
>>Probably the most common problem with scripts is that they have be  
>>both readable and executable in order to work. Just a simple thing to  
>>check.
>>  
> 
> chmod +0777 /usr/local/bin/MyBlaster.pl
> chmod +x /usr/local/bin/MyBlaster.pl

They don't, however, have to be world writable and it's bad practice -- 
even on a dedicated system on a safe LAN -- to make things world 
writable.  0755 maybe, but not 0777.

Are you running your command line test (which works) as the same user 
that mythbackend is running?  This script will have to access some 
device, which will also have permission issues if mythbackend isn't 
running as root.

Beware also if you're running mythbackend as setid root: perl may see 
that real-user != effective user and try to run a taint-controlled 
version.  That can be tricky to get working.

Len