I want to reload the .asoundrc file to switch between hdmi and the 3.5mm jack.
I'm able to switch between the two by software which switches the content of .asoundrc, but it only switches my sound output after I play a new file or reboot the system.
I've tried the following to reload the file.
sudo alsa force-reload
Which returns: sudo: alsa: command not found
sudo /etc/init.d/alsa-utils stop
sudo alsactl kill rescan
sudo /etc/init.d/alsa-utils start
Doesnt return an error, but doesn't work either
Related
I am training myself on Linux with a Raspberry Pi 400 (OS: Raspbian) and I would like to setup my personal config file for apps (notably the Terminal in Zsh). I am able to setup my config onto the terminal with the following:
$ cd .dotfiles
$ ./export.sh
$ cd zsh/
$ source ./zshrc
The problem comes when I quit the terminal or if I open a new terminal or if I reboot the computer, the config is not "saved".
I am not an expert, but for changing bash to zsh and maintaining it as default shell language, I did the following:
$ nano /etc/passwd
and changed the following line from :
pi:x:1000:1000:,,,:/home/pi:/bin/bash
to:
pi:x:1000:1000:,,,:/home/pi:/bin/zsh
This move managed to get me zsh from start every time now. I am wondering if i can directly source my .zshrc with the same technique ... Or would you have any better idea?
I would like to avoid repeating the sourcing steps at every start in the terminal ...
I'm working on a small project right now. I want the python script to automatically run after loggin into the GUI.
I followed the steps here: https://www.raspberrypi.org/forums/view ... 91&t=65607
But it didn't work for me. What it did was whenever I open up the terminal, the script will run automatically, but not after loggin into the GUI.
So I figured a easy solution is to configure the system so terminal runs after loggin into GUI.
Any suggestions?
To auto-start the terminal on boot, open this file with nano:
nano ~/.config/lxsession/LXDE-pi/autostart
Add this line to the end of the file:
#lxterminal
Close, save and reboot
Reference and some other goodies to run a script on startup as well which may have been what you are actually looking for:
http://blog.startingelectronics.com/auto-start-a-desktop-application-on-the-rapberry-pi/
When you edit or create autostart file in your user space like
~/.config/lxsession/LXDE-pi/autostart
then, this file will override global lxsession autostart file in
/etc/xdg/lxsession/LXDE-pi/autostart
so you should copy everything from global file to your newly created file.
By this way , after reboot you won't get a blank screen running openbox.
So, your file should contain
#lxpanel --profile LXDE-pi
#pcmanfm --desktop --profile LXDE-pi
#xscreensaver -no-splash
point-rpi
And then add your necessary startup items at the bottom like
#lxterminal
In case you want to launch a terminal and automatically run a script inside it, you can do so by passing the --command parameter to the lxterminal command.
Open the autostart file
sudo nano /etc/xdg/lxsession/LXDE-pi/autostart
Edit the autostart file
Right above the #xscreensaver line, add #lxterminal --command=/path/to/script"
My autostart file looks something like this.
#lxpanel --profile LXDE-pi
#pcmanfm --desktop --profile LXDE-pi
#lxterminal --command="/path/to/script"
#xscreensaver -no-splash
point-rpi
Note: In some places, it is suggested to use the -e flag instead of --command parameter in lxterminal, however that did not work for me. This did.
i just installed mongopi from https://github.com/RickP/mongopi and it working correctly after doing a few adjustments mainly $ sudo chown $USER /data/db. However my mongo and mongod calls arent persistent i do PATH=$PATH:/opt/mongo/bin/ &
export PATH however this does not last on next ssh session. Also how can I make mongo initialize at startup? I did all the steps from the github repo.
For the path part of the question:
To get the path working you should put it in a script that runs every time you log in. Generally there is a rc-file for you shell in your home directory. Type
echo $SHELL
to see what shell you are running. Go to your home directory:
cd
and then open the file that is called .(your shell)rc - that is, if you are running bash, open .bashrc
nano .bashrc
add the path at the end of this file:
PATH=$PATH:/opt/mongo/bin
export PATH
For the initialization part of the question:
Download and edit this script: Mongo init.d at github
You'll need to change the value of the DEAMON at line 50. I had some other troubles, but you should probably be ok if you create a configuration file (that probably could be empty) and refer to it from line 57. Also, you need to add a mongodb user that the server should run as. You can edit this on line 95, but the default is probably a good idea.
When all this editing is done, you move the file to /etc/init.d/mongodb, like so:
sudo mv init.d /etc/init.d/mongodb
and then add it to the systems start-up routine
sudo update-rc.d mongodb defaults
(This is presuming you run debian. Other distros may have other commands to do this.)
Now, see to that you are not running mongod some other place, and control the service by
sudo service mongodb start
service mongodb status
sudo service mongodb stop
... and so on. This will also run automatically on start-up and shutdown.
I have a source code that runs perfectly fine on Ubuntu, it does some copumtations, and at some points it beeps like this
system("beep -f 400 -l 500");
On Ubuntu I had to do
apt-get install beep
However, I migrated to OpenSuse (not my choice) and now I get this message "sh: beep: command not found", as the command and package are obviously different.
Does anybody know hot to trigger the system beep sound and define the duration and frequency? I have been able to find only one way to change the parameters
setterm -bfreq 500 -blength 500
, but no way to actually trigger the system bell (beep). The following things don't work
echo ^G
echo -e "\a"
PS - the system Bell is enabled at
Configure Desktop -> Application and System Notifications -> System Bell
and you can actually play with this
So, I did what #fvu proposed.
However, one needs to have sudo rights, to do so, otherwise (e.g. at my work-place we don't have sudo rights) there is this output message
Could not open /dev/tty0 or /dev/vc/0 for writing open: No such file or directory
In this case, you should:
sudo chmod 4755 /usr/bin/beep
as proposed here
I noticed that on my OpenSuse 12.3 system, the bell is working in xterm or gnome-terminal, but not in konsole or xfce4-terminal.
If the same applies to your system, then maybe a work-around could be creating a shell script called "beep" which calls xterm and rings the bell:
#!/bin/sh
xterm -e "echo -e '\a'; sleep 1"
I used QEMU to bring CentOS.img (downloaded some where). I find the boot screen of CentOS.img took over the console session of the current terminal and I could see CentOS booting up process and prompts me to the login screen of the guestVM CentOS. This is really helpful for me as I ran QEMU instance from remote console machine.
Now, I created a new RHEL.img using iso and when I try to boot it; I was not able to see anything in the screen other then some symbol of (Y) :(
$>/usr/libexec/qemu-kvm -hda ./RHEL.img -bios bios.bin -nographic -net nic,model=e1000,macaddr=00:AD:BE:EF:4F:BD -net tap,script=./qemu-ifup -m 1024 -smp 2
...Y
on investigation, I find we can do it by redirecting RHEL boot to console using
# virt-edit RHEL_VM /boot/grub/grub.conf
...
title rhel (2.6.38.6-26.rc1.fc15.x86_64)
root (hd0,0)
kernel /vmlinuz ro [...] console=ttyS0
...
but nothing worked out. I am trying to bring the rhel VM session to the same console where I invoked qemu-kvm from remote terminal. Thanks in advance.
NOTE: I don't have GUI enabled on the physical host machine.
You could try adding a serial port and sending output to that. Although you do have to be able to boot it at least once to do these steps...
You might get lucky if you just add a serial port to the qemu command line and then telnet to that; hoping linux detects this and sends output there
edit /etc/init/ttyS0.conf and add
respawn
console none
start on (local-filesystems)
stop on [!12345]
script
exec start ttyS0
end script
then
ln -s /etc/init/ttyS0.conf /etc/rc2.d/S99ttyS0.conf
ln -s /etc/init/ttyS0.conf /etc/rc0.d/S99ttyS0.conf
ln -s /etc/init/ttyS0.conf /etc/rc6.d/S99ttyS0.conf
then do this to enable grub
Edit /etc/default/grub
1. Edit the GRUB_CMDLINE_DEFAULT="" line to start the console on /dev/ttyS0
GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,38400n8"
2. Add a serial console section
# Serial console
GRUB_TERMINAL=serial
GRUB_SERIAL_COMMAND="serial --speed=38400 --unit=0 --word=8 --parity=no --stop=1"
3. Rebuild the grub.cfg file
sudo sh
grub-mkconfig > /boot/grub/grub.cfg