ysap's questions

I am using Ubuntu/gnome (10.04) to remotely connect to two (slightly different) embedded systems running Ubuntu (12.04). I use the following command for connection:

ssh -X -l username 192.168.1.blah

Then, in the terminal I can use a command that run a GUI based program, say gedit:

gedit filename.txt

Now, on the first system, a nice gedit window is opened on my PC desktop, allowing me to edit the remote file. However, on the second system, I get the following error message:

** (gedit:3637): WARNING **: Could not connect to session bus

Why is it so, and how can I make the 2nd connection to work like the 1st one?

UPDATE 1: The 1st machine reports linaro 12.03, not 12.04

UPDATE 2: Here's the output for dbus search (dpkg -l *dbus* | grep ^i) on the 1st machine:

ii  dbus                                   1.4.14-1ubuntu1                                            simple interprocess messaging system (daemon and utilities)
ii  dbus-x11                               1.4.14-1ubuntu1                                            simple interprocess messaging system (X11 deps)
ii  gir1.2-dbusmenu-glib-0.4               0.5.0-0ubuntu4~linaro2                                     typelib file for libdbusmenu-glib4
ii  gir1.2-dbusmenu-gtk-0.4                0.5.0-0ubuntu4~linaro2                                     typelib file for libdbusmenu-gtk4
ii  libdbus-1-3                            1.4.14-1ubuntu1.3                                          simple interprocess messaging system (library)
ii  libdbus-1-dev                          1.4.14-1ubuntu1.3                                          simple interprocess messaging system (development headers)
ii  libdbus-glib-1-2                       0.94-4                                                     simple interprocess messaging system (GLib-based shared library)
ii  libdbus-glib1.0-cil                    0.5.0-3build1                                              CLI implementation of D-Bus (GLib mainloop integration)
ii  libdbus1.0-cil                         0.7.0-4                                                    CLI implementation of D-Bus
ii  libdbusmenu-glib4                      0.5.0-0ubuntu4~linaro2                                     library for passing menus over DBus
ii  libdbusmenu-gtk3-4                     0.5.0-0ubuntu4~linaro2                                     library for passing menus over DBus - GTK+ version
ii  libdbusmenu-gtk4                       0.5.0-0ubuntu4~linaro2                                     library for passing menus over DBus - GTK+ version
ii  libdbusmenu-qt2                        0.9.0-0ubuntu2                                             a Qt library that implements the DBusMenu spec
ii  libdconf-dbus-1-0                      0.10.0-0ubuntu1                                            simple configuration storage system - D-Bus library
ii  libnih-dbus1                           1.0.3-4ubuntu2                                             NIH D-Bus Bindings Library
ii  libqt4-dbus                            4:4.7.4-0ubuntu8.1linaro1                                  Qt 4 D-Bus module
ii  python-dbus                            0.84.0-2                                                   simple interprocess messaging system (Python interface)
ii  qdbus                                  4:4.7.4-0ubuntu8.1linaro1                                  Qt 4 Dbus Tool

And here it is for the 2nd machine:

ii  dbus                                   1.4.18-1ubuntu1                            simple interprocess messaging system (daemon and utilities)
ii  dbus-x11                               1.4.18-1ubuntu1                            simple interprocess messaging system (X11 deps)
ii  gir1.2-dbusmenu-glib-0.4               0.6.1-0ubuntu3                             typelib file for libdbusmenu-glib4
ii  gir1.2-dbusmenu-gtk-0.4                0.6.1-0ubuntu3                             typelib file for libdbusmenu-gtk4
ii  gir1.2-gjsdbus-1.0                     1.32.0-1ubuntu1                            GObject introspection data for GJS
ii  gstreamer-dbus-media-service           0.1.17-upstream-0ubuntu3                   Media service for Ubuntu Mobile
ii  libdbus-1-3                            1.4.18-1ubuntu1                            simple interprocess messaging system (library)
ii  libdbus-glib-1-2                       0.98-1ubuntu1                              simple interprocess messaging system (GLib-based shared library)
ii  libdbusmenu-glib4                      0.6.1-0ubuntu3                             library for passing menus over DBus
ii  libdbusmenu-gtk3-4                     0.6.1-0ubuntu3                             library for passing menus over DBus - GTK+ version
ii  libdbusmenu-gtk4                       0.6.1-0ubuntu3                             library for passing menus over DBus - GTK+ version
ii  libdbusmenu-qt2                        0.9.2-0ubuntu1                             Qt implementation of the DBusMenu protocol
ii  libnih-dbus1                           1.0.3-4ubuntu9                             NIH D-Bus Bindings Library
ii  libqt4-dbus                            4:4.8.1-0ubuntu4                           Qt 4 D-Bus module
ii  python-dbus                            1.0.0-1ubuntu1                             simple interprocess messaging system (Python interface)
ii  python-dbus-dev                        1.0.0-1ubuntu1                             main loop integration development files for python-dbus
ii  qdbus                                  4:4.8.1-0ubuntu4                           Qt 4 D-Bus tool

I have a VMware Player virtual machine setup, running Ubuntu 10.04 as the a guest OS.

The VM was created on a 20GB virtual drive, with a single partition for working space. Finally I got to the point where I need to expand the size of the virtual drive. Resizing the drive itself, adding some 10GB, was easy via the VMware Player menus. I now need to resize the main partition itself (I prefer this over creating a separate partition and mounting it).

According to GParted, I now have the following partitions:

My question is, how can I increase the size of the Filesystem partition to include the free 10GB?

From information I found online, it looks like one limitation is the fact that he swap partition is immediately adjacent to the filesystem, so my understanding is that first thing would be to move that partition to the end of the volume. How can this be done?

Also, some sources suggest that the system should be booted from a LiveCD, so the filesystem is not the boot partition, and thus make it easier to resize. As mentioned above, I run a VM, so I am not sure how to boot it from a LiveCD. Any ideas?

I am running Ubuntu on an ARM based embedded system that lacks a battery backed RTC. The wake-up time is somewhere during 1970. Thus, I use the NTP service to update the time to the current time.

I added the following line to /etc/rc.local file:

sudo ntpdate -s time.nist.gov

However, after startup, it still takes a couple of minutes until the time is updated, during which period I cannot work effectively with tar and make.

How can I force a clock update at any given time?

UPDATE 1: The following (thanks to Eric and Stephan) works fine from command line, but fails to update the clock when put in /etc/rc.local:

$ date ; sudo service ntp stop ; sudo ntpdate -s time.nist.gov ; sudo service ntp start ; date
Thu Jan  1 00:00:58 UTC 1970
 * Stopping NTP server ntpd     [ OK ] 
 * Starting NTP server          [ OK ] 
Thu Feb 14 18:52:21 UTC 2013

What am I doing wrong?

UPDATE 2: I tried following the few suggestions that came in response to the 1st update, but nothing seems to actually do the job as required. Here's what I tried:

1. Replace the server to us.pool.ntp.org
2. Use explicit paths to the programs
3. Remove the ntp service altogether and leave just sudo ntpdate ... in rc.local
4. Remove the sudo from the above command in rc.local

Using the above, the machine still starts at 1970. However, when doing this from command line once logged in (via ssh), the clock gets updated as soon as I invoke ntpdate.

Last thing I did was to remove that from rc.local and place a call to ntpdate in my .bashrc file. This does update the clock as expected, and I get the true current time once the command prompt is available.

However, this means that if the machine is turned on and no user is logged in, then the time never gets updates. I can, of course, reinstall the ntp service so at least the clock is updated within a few minutes from startup, but then we're back at square 1.

So, is there a reason why placing the ntpdate command in rc.local does not perform the required task, while doing so in .bashrc works fine?

Using Ubuntu Software Center I can perform a search on an approximate package name and get the matching packages list to select from.

If I work on a remote machine via ssh (i.e. command line only), how do I perform such a search?

On an embedded system with a very limited disk space I have the folder /var/cache/apt full with some 700MB of srcpkgcache.bin.* and a couple of large *.bin files.

Performing sudo apt-get clean did not make a visible difference.

Is it safe to manually delete these *.bin* files?

I have a DELL U2410 monitor connected to a Compaq 100B desktop equipped with an integrated AMD/ATI graphics card (AMD E-350). The installed O/S is Ubuntu 10.04 LTS.

The computer is connected to the monitor via the DVI connection.

The problem is that I cannot set the desktop resolution to the native 1920x1200. The maximum allowed resolution is 1600x1200.

Doing some research I found about the xrandr utility. Unfortunately, when trying to use it I cannot configure it to the required resolution. First, it does not report the output name (which supposed to be DVI-0), saying default instead. Without it I cannot use the --fb option.

The EDID utility seems to identify the monitor well. Here's the output from get-edid:

    # EDID version 1 revision 3
Section "Monitor"
    # Block type: 2:0 3:ff
    # Block type: 2:0 3:fc
    Identifier "DELL U2410"
    VendorName "DEL"
    ModelName "DELL U2410"
    # Block type: 2:0 3:ff
    # Block type: 2:0 3:fc
    # Block type: 2:0 3:fd
    HorizSync 30-81
    VertRefresh 56-76
    # Max dot clock (video bandwidth) 170 MHz
    # DPMS capabilities: Active off:yes  Suspend:yes  Standby:yes

    Mode    "1920x1200" # vfreq 59.950Hz, hfreq 74.038kHz
        DotClock    154.000000
        HTimings    1920 1968 2000 2080
        VTimings    1200 1203 1209 1235
        Flags   "-HSync" "+VSync"
    EndMode
    # Block type: 2:0 3:ff
    # Block type: 2:0 3:fc
    # Block type: 2:0 3:fd
EndSection

but the xrandr -q command returns:

Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200
default connected 1600x1200+0+0 0mm x 0mm
   1600x1200       0.0* 
   1280x1024       0.0  
   1152x864        0.0  
   1024x768        0.0  
   800x600         0.0  
   640x480         0.0  
   720x400         0.0  

When I try to set the resolution, I get:

$ xrandr --fb 1920x1200
xrandr: screen cannot be larger than 1600x1200 (desired size 1920x1200)

$ xrandr --output DVI-0 --auto
warning: output DVI-0 not found; ignoring

How can I set the screen resolution to 1920x1200? Why doesn't xrandr identify the DVI-0 output?

Note that the same computer running Ubuntu version higher than 10.04 detects the correct resolution with no problems. On this machine I cannot upgrade due to some legacy hardware compatibility problems.

Also, I don't see any optional screen drivers available in the Hardware Drivers dialog.

----

UPDATE:

following the answer to this question, I got some advance. Now the required mode is listed in the xrandr -q list, but I can't switch to that mode. Using the Monitors applet (which now shows the new mode), I get the response that:

The selected configuration for displays could not be applied. Could not set the configuration to CRTC 262.

From the command line it looks like this:

$ cvt 1920 1200 60
# 1920x1200 59.88 Hz (CVT 2.30MA) hsync: 74.56 kHz; pclk: 193.25 MHz
Modeline "1920x1200_60.00"  193.25  1920 2056 2256 2592  1200 1203 1209 1245 -hsync +vsync

$ xrandr --newmode "1920x1200_60.00"  193.25  1920 2056 2256 2592  1200 1203 1209 1245 -hsync +vsync

$ xrandr -q
Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200
default connected 1600x1200+0+0 0mm x 0mm
   1600x1200       0.0* 
   1280x1024       0.0  
   1152x864        0.0  
   1024x768        0.0  
   800x600         0.0  
   640x480         0.0  
   720x400         0.0  
  1920x1200_60.00 (0x120)  193.0MHz
        h: width  1920 start 2056 end 2256 total 2592 skew    0 clock   74.5KHz
        v: height 1200 start 1203 end 1209 total 1245           clock   59.8Hz

$ xrandr --addmode default 1920x1200_60.00

$ xrandr -q
Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200
default connected 1600x1200+0+0 0mm x 0mm
   1600x1200       0.0* 
   1280x1024       0.0  
   1152x864        0.0  
   1024x768        0.0  
   800x600         0.0  
   640x480         0.0  
   720x400         0.0  
   1920x1200_60.00   59.8  

$ xrandr --output default --mode 1920x1200_60.00
xrandr: Configure crtc 0 failed

Another piece of info (if it helps anyone):

$ sudo lshw -c video
  *-display UNCLAIMED     
       description: VGA compatible controller
       product: ATI Technologies Inc
       vendor: ATI Technologies Inc
       physical id: 1
       bus info: pci@0000:00:01.0
       version: 00
       width: 32 bits
       clock: 33MHz
       capabilities: pm pciexpress msi bus_master cap_list
       configuration: latency=0
       resources: memory:c0000000-cfffffff(prefetchable) ioport:f000(size=256) memory:feb00000-feb3ffff

----

UPDATE 2: Here's the updated lshw listing:

$ sudo lshw -numeric -c video
  *-display UNCLAIMED     
       description: VGA compatible controller
       product: ATI Technologies Inc [1002:9802]
       vendor: ATI Technologies Inc [1002]
       physical id: 1
       bus info: pci@0000:00:01.0
       version: 00
       width: 32 bits
       clock: 33MHz
       capabilities: pm pciexpress msi bus_master cap_list
       configuration: latency=0
       resources: memory:c0000000-cfffffff(prefetchable) ioport:f000(size=256) memory:feb00000-feb3ffff

I was looking for the difference between the "." and "source" builtin commands and a few sources (e.g., in this discussion, and the bash manpage) suggest that these are just the same.

However, following a problem with environment variables, I conducted a test. I created a file testenv.sh that contains:

#!/bin/bash
echo $MY_VAR

In the command prompt, I performed the following:

> chmod +x testenv.sh
> MY_VAR=12345
> ./testenv.sh

> source testenv.sh
12345
> MY_VAR=12345 ./testenv.sh
12345

[note that the 1st form returned an empty string]

So, this little experiment suggests that there is a difference after all, where for the "source" command, the child environment inherits all the variables from the parent one, where for the "." it does not.

Am I missing something, or is this is an undocumented/deprecated feature of bash?

[ GNU bash, version 4.1.5(1)-release (x86_64-pc-linux-gnu) ]

I was asked to reconfigure and make some order in a FTP server which is operating on Ubuntu 10.04. I have root access to the machine.

When checking what server is running, I get:

# ps -ef | grep ftp
root      2287     1  0 Mar19 ?        00:00:00 /usr/sbin/vsftpd
root     26380 26369  0 Jun27 ?        00:00:02 /usr/lib/openssh/sftp-server

From the man pages I understand that vsftpd and sftp-server are both FTP server software. How can I tell which server is actually serving an FTP request from a remote machine?

I run Ubuntu 10.04 64-bit as a guest OS on a VMWare Player machine over Windows 7. I have the clock displayed in the panel and the location set to my time zone. Occasionally, I close VMWare Player using the VM -> Power -> Suspend menu. When I turn the Ubuntu on again, the clock is no longer in sync with the real system clock.

How can I make the clock to auto sync when the system is resumed from suspension?

We have a couple of (identical) Ubuntu 11.10 machines, configured with gnome-classic, which we use as remote servers, and let our clients log into personal user accounts we create for them using vnc4server.

We configured all the machines in the same way, following a short manual we compiled, describing how to download, install and prepare a few tools and our software.

The connection usually works fine, but today I set up a fresh machine, and experienced problems.

After installing vnc4server, I ran vncpasswd and copied the following startup file to ~/.vnc/xstartup:

#!/bin/sh  
unset SESSION_MANAGER  
unset DBUS_SESSION_BUS_ADDRESS  
gnome-session --session=gnome-classic &  
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup  
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources  
xsetroot -solid grey  
vncconfig -iconic &  

Then, I started vnc4server and used two viewers (the Ubuntu Remote Desktop Viewer and Windows RealVNC Client) in two other machines, but instead of getting my desktop, I see an empty window with a grey-ish background pattern like this:

and the cursor is a bold X.

What is wrong with the setup and why don't I get a remote session as expected?

I have a remote system on which I defined two accounts - an administrator and a standard user. The machine was fallbacked from Unity to GNOME. I use vnc4server to remotely connect to the system, and RealVNC Viewer for the actual connection from my Win 7 laptop.

From the two accounts I started the servers as:

>> vnc4server -geometry 1440x900

I also have the following ~/.vnc/xstartup file in both accounts:

#!/bin/sh
# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
gnome-session --session=gnome-classic &
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &

Now, when I connect to the admin account, I get a desktop and can open a terminal to type my commands.

On the user account, however, I can do the same - but when I type the d key, the terminal minimizes, until I press the key again. What's going on here? How can I claim my d back?

EDIT: thanks to @zigg, I found the problem. I wonder, though, where does it inherited the "D" shortcut from? This is a fresh account and the changes I made were just to the .vnc file above???

I am trying to find diffs between all files of same names across two copies of a directory (say a working and a backup). For example, I can diff two files of same name in both:

> diff d1/f.cpp d2/f.cpp

or I can find differences across the directories:

> diff d1 d2

but how can I find differences between the *.cpp files only?

> diff d1/*.cpp d2/*.cpp

does not seem to work (for obvious reasons).

[It is probably easy to solve with loops, but I am trying to find a more elegant way]

I am using a Logitech Anywhere Mouse MX on my Ubuntu. Mouse works well, but I can't assign the actions to the extra buttons available on it. What I miss the most is the "back" and "forward" actions assigned to the scroll wheel tilt left and right.

How can I activate these features?

In order to change a symbolic link, one can use the -fs option to eliminate the need to unlink or delete the old link first. However, trying to do so on directories does not seem to work:

$ mkdir dir1
$ mkdir dir2
$ ln -s  dir1 lnk
$ ln -sf dir2 lnk
$ ll
......... lnk -> dir1
$

Why so? Is there another option to do this with directories the same as with files?

I am running 16 debug processes simultaneously with our adapted gdb (called e-gdb). The processes are invoked by a bash script, using:

gnome-terminal -e 'e-gdb -x gdbNN.cmd progNN.e'

To manage the multiple sessions I can open multiple terminals using the --geometry option to arrange them tiled on my screen. Alternatively, I can use the --tab option to have them all in one terminal.

When the sessions end I close the terminal(s) with a click (I don't want it to auto-close).

So, with multiple terms I need to click 16 times while with tabs I click once, but I have to switch between tabs to see the session results. I would like tiled tabs in a terminal so I can view them simultaneously and close all in a single click.

Is there a way to tile tabs? If not, can I close all debug terminals in one action?

UPDATE: Is there an easy way to kill multiple terminals based on their title? I am using the -t option to name the windows. Is there something like kill -name '*DBG*'?

Following this, I added a couple of modified background images to the backgrounds collection. Now, I want to select a different background for the login screen. How do I do that?

UPDATE: Just tried David's solution on a fresh installation of Ubuntu 11.10. It seems like the file: /usr/share/applications/gnome-appearance-properties.desktop does no longer exist. Any idea on what I can use instead?

I am about to ship a new 10.04 installed system to a customer. This is the 1st system that we are shipping with our preinstalled software and an additional hardware test platform, so I thought it would be a nice idea to have the desktop wallpaper include our company's logo.

What I want to do is just to add the logo to the default background image. the questions are:

1. Where are the set of backgrounds stored?
2. What are the rules for creating a custom background from scratch?
3. If I create a background from scratch, how do I add it to the system's background set (i.e., not just save it in the user's Pictures directory - I want it to be available to all future users of the machine)?