Remove repo after adding it via deb I've added a repo with the following:  add-apt-repository "deb http://archive.ubuntu.com/ubuntu artful universe"   How would I remove it? I'm using this in a automated script also!
How can PPAs be removed? I've added many PPAs using the add-apt-repository command. Is there a simple way to remove these PPAs? I've checked in /etc/apt/sources.list for the appropriate deb lines but they aren't there.   This is on a server system so a command line solution would be great!
Does Java have buffer overflows? I want to disable Bluetooth on my laptop running Windows 10 Pro x64, but I have a problem: the option to do so is missing even though I know that it was previously available.  Here is the Bluetooth settings pages should look like on Windows 10:    Here is how it looks for me:    As you can see, I am missing the switch to turn it on or off? Why is it missing? I know that just yesterday, it was available and I turned it off. What can I do to fix it? Lie algebra of $\left(\begin{smallmatrix}a & b\\ & a^2\end{smallmatrix}\right )$ in $GL_2(\mathbb{R})$ I'm working on the question     Let $G$ be the group of invertible real matrices of the form $\left [\begin{array}{c c}a &amp; b\\ &amp; a^2\end{array}\right ]$. Determine the Lie algebra $L$ of $G$, and compute the bracket on $L$.   I'm familiar with how to derive the Lie algebra for a linear group like $U_n$, $SU_n$, etc. but I'm not sure what to do in a more explicit case like this. Anyone know a quick easy way to migrate a SQLite3 database to MySQL? Let $G$ be a finite group and $F$ a field with $\mathrm{char}(F)=0$ or coprime to $|G|$. Let $V$ be a $FG$-module in a way that every $ FG$-homomorphism $ f : V \to V $ is given by $f(x)= \lambda x $. Then $V$ is irreducible.   I already managed to proof this by contradiction, using Maschke's Theorem. We can  write $V$ as $U\oplus W$ and get a $FG$-homomorphism $\pi:U\oplus W \to U\oplus W$, $\pi (u+w)=u$, then $\pi(u+w)=\lambda (u+w)=u $ then either $U$ or $W$ are trivial and thus $V$ is irreducible.  My question is if this statements still holds if the characterictic of $F$ divides the order of $G$, since I only used this fact in my proof to use Maschke's theorem. Very large log files, what should I do? The Challenge  I have been trying to write a filter that applies (prepends a string) to (a) post titles of a certain post type and (b) to that same post type WordPress admin backend for use by an auto social sharing plugin.  I've gotten really close.  I've achieved: 1.  prepending only to custom post_type post titles 2.  prepending to custom_post type titles AND all nav menu items 3.  prepending to ALL titles (post, page, nav menu, and backend auto-sharing plugin)  The final, 3rd attempt got me very hopeful, but yet still, no matter the function, conditional statement, or combination I use, I can't get custom_post title AND backend social sharing plugin, but not nav menu items.  My Code - what I've tried  I've tried different conditionals, like is_admin() and !is_nav_menu with all nav menu IDs.  I've also tried comparing the ID of the post to the ID of the menu.  Finally, I've also tried adding the filter only to loop_start and that seems promising if combined with other statements.  I will clean up my code for your review but I leave it this way for now in hopes it helps to see what I've tried and maybe where I went wrong with any of those methods.  // , $id = NULL function append_album_review_to_title( $title ) {     global $post;     global $dont_apply_title_filter;     $text = 'Album Review: ';     $prepended_title = $text . $title; /*     $nav_menus_obj = wp_get_nav_menus();     $nav_menu_ids = '';     foreach( $nav_menus_obj as $nav_menu ) {         $nav_menu_ids .= $nav_menu-&gt;term_id . ',';     }     rtrim($nav_menu_ids, ','); */ //  if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; in_the_loop() ){ //  if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; $id == get_the_ID() ){ //  if ( !is_nav_menu( '32057,32058,35135,32054,32056' ) ) { //  if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; is_nav_menu( $id ) ) {     if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; !$dont_apply_title_filter ) {         //print_r( $nav_menu_ids );         //print_r( is_nav_menu( $nav_menu_ids ) );         return $prepended_title; /*     } elseif ( get_post_type( $post-&gt;ID ) == 'album_review'  ) {         return $title; */     } else {         return $title;     }; } add_filter('the_title', 'append_album_review_to_title'); //add_action('save_post', 'custom_post_type_title', 100); /* function set_custom_title() {     add_filter( 'the_title', 'append_album_review_to_title', 10, 2 ); } add_action( 'loop_start', 'set_custom_title' ); */ Copy existing property from e.g. Properties window to a custom panel So if I have this custom panel in the 3D view, is there a way I can take a property from for example the properties window and paste it onto my panel below the "text" prop, without creating a new property?  The reason I do not want to create a new property is because I want them to share all data, such as values, keyframes, drivers etc.        bl_info = {     "name": "",     "description": "",     "author": "",     "version": (0, 0, 1),     "blender": (2, 70, 0),     "location": "",     "warning": "",      "wiki_url": "",     "tracker_url": "",     "category": "" }  import bpy  from bpy.props import (StringProperty,                        BoolProperty,                        IntProperty,                        FloatProperty,                        FloatVectorProperty,                        EnumProperty,                        PointerProperty,                        ) from bpy.types import (Panel,                        Operator,                        AddonPreferences,                        PropertyGroup,                        )   class inouse_Settings(PropertyGroup):      my_bool = BoolProperty(         name="Enable or Disable",         description="A bool property",         default = False)     class UV_OT_my_panel(Panel):     bl_space_type = 'VIEW_3D'     bl_idname = "UV_OT_my_panel"     bl_label = "Custom"     bl_category = "Custom"     bl_region_type = 'TOOLS'      def draw(self, context):          scn = context.scene         mytool = scn.inhouse         layout = self.layout          col = layout.column(align=True)         row = col.row(align = True)         row.prop(mytool, "my_bool", text="Text")       def register():     bpy.utils.register_module(__name__)     bpy.types.Scene.inhouse = PointerProperty(type=inouse_Settings)  def unregister():     bpy.utils.unregister_module(__name__)     del bpy.types.Scene.inhouse  if __name__ == "__main__":     register() Options to hide reputation information on Stack Overflow? Why do we have no enzyme to digest cellulose? As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have an enzyme to digest cellulose? Java: Load class from string Embedding $S_n$ into $A_{n+2}$ Researching English/Christian families in India during first half of 19th century? How do I move the "Show Applications" icon in Ubuntu Dock? Ubuntu 17.10 introduces the GNOME Shell with the  (based on  GNOME Shell extension) and it allows you to put the Dock on the bottom of the desktop:    However, there is no easy way to move the Show Applications icon (shown on the right) to the left of the Dock. There is no such setting in GNOME Control Center. There is already a  filed, but does anybody know any workaround until it gets fixed by Ubuntu Dock developers? I am running Ubuntu 14.04 and Notepad++ 6.6.4 (through WINE)  Under the 'Run' tab, I clicked on "Launch in Firefox" , but nothing happened   I uninstalled Notepad++ and WINE, then shutdown. I re-installed Notepad++ and WINE and still have the same problem.   Does anyone know what the problem is? How to force the browser to reload cached CSS and JavaScript files How to AutoSize the height of a Label but not the width How can I duplicate a mesh along a curve? I want to outline a curve in the form of text with a mesh (UV-sphere, cube etc.). How can I do that while saving mesh geometry without using the Curve modifier? I need to calculate the following determinant in order to prove the following equality:  $$\det\begin{pmatrix} a &amp; b &amp; c &amp; d \\ -b &amp; a &amp; -d &amp; c \\ -c &amp; d &amp; a &amp; -b \\ -d &amp; -c &amp; b &amp; a \end{pmatrix} = (a^2+b^2+c^2+d^2)^2.$$  I tried using Gauss-algorithm to get an easier matrix, but I'm not sure if I did it correctly.  Calling the $4$ lines $I$, $II$, $III$ and $IV$, I did:  (1) $II \cdot a$  (2) $III \cdot a$  (3) $IV \cdot a$  After this I did:  (4) $II' + I \cdot b$  (5) $III' + I \cdot c$  (6) $IV' + I \cdot d$  So finally I got the following matrix:  $$\begin{pmatrix} a &amp; b &amp; c &amp; d \\ 0 &amp; a^2+b^2 &amp; bc-ad &amp; ac+bd \\ 0 &amp; ad+bc &amp; a^2+c^2 &amp; cd-ab \\ 0 &amp; bd-ac &amp; ab-cd &amp; a^2+d^2 \end{pmatrix}.$$  I thought this would make the determinant a bit easier, unfortunately I must have done something wrong. Is multiplication with single lines allowed as I have done it?  Thank you very much. Why does $A\sin{k(x+c)}=a\sin{kx}+b\cos{kx}$ imply that $A=\sqrt{a^2+b^2}$ and $\tan{c}=-b/a$? I don't understand this. These identities are given in the online notes for MIT's 18.01 calculus class. It's related to taking the sum of two trig functions and transforming them into a single trig function. I can use the formulas to do this, but I am having trouble finding anything on the internet to use a proof for my understanding.  Thanks for any responses!  EDITED (added after the first answer):  Sorry, the identity goes like this:  $A\sin{k(x-c)}=a\sin{kx}+b\cos{kx}$ ,  with the relationships  $a=A\cos{kc}$ , $b=-A\sin{kc}$ , $A=\sqrt{a^2+b^2}$ , and $\tan{kc}=-b/a$