Today, all of a sudden, I thought that less doesn’t function, by default, the way I would like. So I read the manual page. These options will make “less” not wrap long lines and also will make it scroll horizontally one character at a time, instead of half the screen width. This way it’s easier to follow which long line is which.
A short post that is not about SUSE; it’s just something I had to get done. BackTrack starts by default in text mode, it the intended behavior. If you’d like to have a GUI that starts automatically, read on.
1. make sure you have KDM installed
dpkg --list kdm
It should be there, it’s installed by default. If you use Gnome, you need GDM, that is not installed by default, so install it this way:
apt-get install gdm
2. remove the “text” option in /etc/default/grub
Edit this line and delete the “text” option
GRUB_CMDLINE_LINUX_DEFAULT="text splash vga=791"
3. update grub.cfg
By now, you should have KDM on your screen. It’s going to appear when you reboot, too.
And since you’re here, maybe you also want to configure this:
Remote connection through VNC
1. install tightvncserver
apt-get install tightvncserver
2. edit /etc/services
Add the line below. You might want to do it at the proper sorted position, by port number.
This post walks you through the steps to make some user accounts that can connect only by sftp (Secure FTP, a subsystem of openSSH) and are chrooted into their home directories. That is, they can’t see anything else outside their homes. You will be able to have other regular users on the system, the sftp-only users will be a special group.
Create a volume for chroot homes and mount it with options nodev, nosuid
This volume is used by the chrooting part of the mechanism. It will contain the home directories of the sftp-only users. The easiest way to make this on an already-installed OS is to create a loop mounted image. You must be root for these commands to work.
su - # become root
dd if=/dev/zero of=/home/sftponly_image.ext3 bs=1M count=512 # this makes a 512 MB volume
mkfs.ext3 /home/sftponly_image.ext3 # create the filesystem. Answer y to "Proceed anyway?"
mkdir /home/sftponly # make a mountpoint
mount -o loop,nodev,nosuid /home/sftponly_image.ext3 /home/sftponly # mount the image
Also you’ll want the image to mount automatically at boot. Add this to /etc/fstab:
Everything up until now was laying the foundation for the actual sftp-only configuration that follows. Without all that, you would see this error in /var/log/messages when you try to login with sftp-only accounts:
sshd[...]: fatal: chroot into directory without nodev or nosuid
Create a sftponly group
Members of this group will be able to connect only by SFTP and will be chrooted to their home directories.
groupadd --system sftponly
Create a sftp user
The following command creates a sftp-only user named “sftpexample” with the home directory inside the mounted image. The user is a member of sftponly group and does not have permission to login with ssh, only sftp.
useradd --comment "SFTP example" --create-home --home /home/sftponly/sftpexample --groups sftponly --shell /bin/false sftpexample
passwd sftpexample # set a password
Add options to SSH daemon configuration file
Add this to /etc/ssh/sshd_config
Match Group sftponly
Reload the ssh daemon:
systemctl reload sshd.service
Verify that it works
Login through sftp and verify the chroot environment:
Connected to localhost.
sftp> cd /
Must not be able to login with ssh:
Connection to localhost closed by remote host.
Connection to localhost closed.
I use an older PC as media player, it’s connected through a HDMI cable to a LCD TV. Most of the people might use, in this case, a media center application like XBMC (packages for openSUSE are available in the packman repository). I have my own reasons for using just plain openSUSE:
I like KDE in openSUSE and I’m proficient in setting it up the way I want
my older PC has little memory, 1 GB with 256 MB shared as video memory for the on-board GeForce 8200 video
need to run a web-browser (Firefox) that I can set up with large fonts to be read at 3 m
I actually like more to run mplayer on the command line to play stuff and pass options to it this way, rather thank click through menus
By default, sound goes to the sound board jack plugs, which means you should connect speakers to hear it. However, the TV has it’s own speakers and sound from the PC can reach them through the HDMI cable.
Go to KDE Configure Desktop, in the Hardware section, choose Multimedia and then Phonon.
The Audio Hardware Setup should look like this:
The Device Preference should look like this:
Click on “Internal Audio Digital Stereo (HDMI)”, then on “Test”. You’d expect that to be enough, but if you’ve come to read this post it might be because it’s not working for you yet. The most probable reason is that the particular output is muted by default. Here’s the magic tool to un-mute it: alsamixer. It can be run in Konsole:
Select the sound card with [F6]
In the next screen, use right arrow [->] to scroll through available channels until you reach S/PDIF 1 and un-mute it with [M]
In your case it might be something else than S/PDIF 1. Just look for channels that are muted, they have a “MM” at the bottom, like “Line” has in the picture above. It helps if you play a song in a different window and just mute/un-mute channels, one by one, in alsamixer.