I downloaded and installed the 3.0.0-21 update to the kernel. It caused several problems including:   Firefox not asking for a folder before placing a URL into bookmarks Ubuntu 11.10 not automatically opening to the desktop (I still haven't figuring out a viable work around).    This may be an inability to hibernate and reinstall, but I believe I also had problems after shutdown and booting.   I have tried to learn how to return to the former 3.0.0-19, but I can't find anything to teach me. I would like to know how to return to the -19 configuration or how to reinstall the -21 configuration.
The latest kernel is causing problems with my sound, which worked fine with an older version. As I have only Ubuntu installed, Grub is not getting displayed while booting. How can I manually choose my kernel version while booting?
Compress a directory using tar/gz over SSH to local computer? I'd like to essentially tar/gz a directory on a remote machine and save the file to my local computer without having to connect back into my local machine from the remote one. Is there a way to do this over SSH? The tar file doesn't need to be stored on the remote machine, only on the local machine. Is this possible? my circuit is shown on the picture. the problem is the output of the mosfet does't work as desired. For example, If I use Vin=100V and the duty cycle is 50%, the output is Vout=19V.  Anyway, the output is not even near to the desired value. can you help, please? Gnome Panel becomes fully transparent when window is not maximised! How do I transfer my Pokemon Go account to another device (Android to Android)? I was having trouble playing the game on my android so I downloaded it to my wife's phone (Galaxy S6). I read some posts on how to get it running on my android and it worked but, my level 7 account is on my wife's phone.  How do I get it back to my android? When I sign out and back in it doesn't ask for any sign in info. I've tried deleting the app's data and even uninstalling and re-installing, but it still doesn't ask for sign-in info. Is returning a pointer to a static local variable safe? I'm working with some code that widely uses the idiom of returning a pointer to a static local variable.  eg:  char* const GetString() {   static char sTest[5];   strcpy(sTest, "Test");   return sTest; }   Am I right in thinking that this is safe?  PS, I know that this would be a better way of doing the same thing:  char* const GetString() {   return "Test"; }   Edit: Apologies, the function signature should of course be:  const char* GetString(); My table doesn't fit; what are my options? My PC has both Ubuntu and Windows 7 installed. I have installed all my drivers in Windows like Nvidia graphics, motherboard etc. Shall I install them in Ubuntu too?  I looked on the web for my Nvidia drivers and I have found a .run file. How could I install it on my Ubuntu? I don't believe it's true that all submodules of a finitely generated free module are free just based on results from google. Is there a canonical simple example of a finitely generated free module with a submodule that is not free? Can I levitate an object without using an electromagnet? we all study mathematics , and all of us learn mathematical methods to solve problems , we learn how to prove , how to think mathematically   but the question is, what is mathematics ? how can we define it as a branch of science ? How to prove wave nature of large object? Why does $(\frac{p-1}{2}!)^2 = (-1)^{\frac{p+1}{2}}$ mod $p$? Assume $p$ is prime and $p\ge 3$.  Through experimentation, I can see that it's probably true. Using Wilson's theorem and Fermat's little theorem, it's equivalent to saying $2^2 4^2 6^2 \cdots (p-1)^2 = (-1)^{\frac{p+1}{2}}$ mod $p$, but I can't figure out any more than that. "I'm not sure what the right way is" I believe the sentence in the title is grammatically correct.   Recently I've seen too many people writing it this way:     I'm not sure what is the right way.   Is it grammatically correct as well? Maybe in a different sense? Or simply misuse by non-native speakers? Construct a command by putting a string into a tty I managed to do this  echo -n "command" &gt; /dev/tty1  The letters appear, and the cursor moves, but they are "ghosts" – if you hit Enter, nothing happens (they are not in stdin).  Edit:  In the middle of the below screenshot, you see why I see the use of this. (The line with a red caption, right below the line with a yellow caption.) As it is now, you are not really "editing" the note text; you are just asked to write a new text, which will replace the text of the note you are (not really) editing. Thus, I thought it could be remedied by simply pasting the old text into the tty: if the user hits enter, no modification is made. (This program is in Perl/MySQL, but I thought it would be more interesting to ask for a general solution than "how do I do this in Perl".)    Edit 2:  Here is the Perl code, that uses the C code below (works exactly as intended), as well as a new screenshot – hopefully this will clarify things beyond doubt :) Again, look at the middle of the screenshot, where the edit is made to the note text - this time around, the old text is there, for example if you just wanted to fix a typo, you won't have to retype the entire note text.  my $edit_note_text = $edit_note_data[2]; print BOLD, RED, " new text: ", RESET; system("writevt /dev/tty \"$edit_note_text\""); my $new_text = &lt;$in&gt;; $new_text = fix_input($new_text); my $set_text = "UPDATE notes SET note = \"$new_text\" WHERE id = $edit_note_id"; $db-&gt;do($set_text); Show that the locus formed by z in the equation $z^3 + iz = 1$  never crosses the co-ordinate axes in the Argand plane. Further show that $$|z| = \sqrt{\dfrac{-\Im(z)}{2\Re(z)\Im(z) +1}}$$  Concept: $z=x+iy$ $z^3=(x+iy)^3=x^3-3xy^2+i(3x^2y-y^3)$ $iz=-y+ix$ Combined equation is $x^3-3xy^2-y-1+i(3x^2y-y^3+x)=0$ How do we proceed from here onward? Does there exist a continuous bijection from $(0,1)$ to $[0,1]$? Of course the map should not be a proper map. How did this person gain possession of the Infinity Stones? Is it worth it to upgrade a Toshiba Satellite C55-A5300 laptop given the latest productivity software requirements? I would like to upgrade a Toshiba Satellite C55-A5300 laptop so it can be as useful as it can be nowadays. I haven’t needed to use much software for a few years now, and I’m not able to gauge whether a maxed out upgrade of this laptop would be up to running the latest versions of MS Office and Acrobat smoothly. Maybe even run some Photoshop and Lightroom? I want to install the best CPU that will work optimally within the parameters of this laptop, including the laptop’s cooling capabilities. I ultimately want improved performance, but I want the performance to be as smooth as possible. From what I gather the Pentium 2030M is the best processor this motherboard will accept. Am I on the right track? I also plan to fully upgrade the memory and the hard disk speed with respective upgrades. What is the max memory per RAM slot (2 total)? What is the fastest speed of RAM I can use?  Copied from the Toshiba spec sheet:  Processor and Graphics Intel® Celeron® Processor 1037U o (2M Cache, 1.80GHz) Mobile Intel® NM70 Express Chipset Mobile Intel® HD graphics with shared graphics memory Memory Memory Configured with 4GB DDR3 1333MHz (max 16GB) 2 main memory slots. One slot is occupied Storage Drive 500GB (5400 RPM) Serial ATA hard disk drive Power 45W (19V 2.37A) 100-240V/50-60Hz AC Adapter Automatic text wrapping in ArcMap layout text element? Reprojecting raster from 0 360 to -180 180 with cutting 180 meridian using gdalwarp I have a geotiff raster image that has a coordinate system with longitudes from 0 to 360. The horizontal center of the image is 180 longitude. See image below:    I want to transform it to EPSG:4326 SRS with -180 180 longtitude range.  And I want the center of the image to be at Greenwich meridian (0). I guess this srs is very widely used. I expect the result look like this:    So I use a gdalwarp command to reproject:  gdalwarp -s_srs '+proj=latlong +datum=WGS84 +pm=180dW' -t_srs EPSG:4326 test_col.tif test_4326.tif   But I only get a tiff with bigger dimensions (more pixels) and EPSG:4326 metadata. The image itself looks the same, as the initial one. But I expect it to swap the hemispheres.  How do I gdalwarp an image to be strictly -180 180 EPSG:4326 with the center in 0 longitude?  This is gdalinfo of my initial file:  Origin = (-0.102272598067084,89.946211604095552) Pixel Size = (0.204545196134167,-0.204423208191126) Metadata:   AREA_OR_POINT=Area Image Structure Metadata:   INTERLEAVE=BAND Corner Coordinates: Upper Left  (  -0.1022726,  89.9462116) (  0d 6' 8.18"W, 89d56'46.36"N) Lower Left  (  -0.1022726, -89.9462116) (  0d 6' 8.18"W, 89d56'46.36"S) Upper Right (     359.897,      89.946) (359d53'50.18"E, 89d56'46.36"N) Lower Right (     359.897,     -89.946) (359d53'50.18"E, 89d56'46.36"S) Center      ( 179.8975000,  -0.0000000) (179d53'51.00"E,  0d 0' 0.00"S)   This is gdalinfo after gdalwarp     Origin = (-180.102727401932952,89.946211604095552) Pixel Size = (0.091397622896436,-0.091420837939082) Metadata:   AREA_OR_POINT=Area Image Structure Metadata:   INTERLEAVE=PIXEL Corner Coordinates: Upper Left  (-180.1027274,  89.9462116) (180d 6' 9.82"W, 89d56'46.36"N) Lower Left  (-180.1027274, -89.9699975) (180d 6' 9.82"W, 89d58'11.99"S) Upper Right ( 179.8211116,  89.9462116) (179d49'16.00"E, 89d56'46.36"N) Lower Right ( 179.8211116, -89.9699975) (179d49'16.00"E, 89d58'11.99"S) Center      (  -0.1408079,  -0.0118929) (  0d 8'26.91"W,  0d 0'42.81"S)