====== Linux ======

==== Installing a Web App via GNOME Web ====

If the web-app is called **"Example"** and it launches **"https://www.example.com"**. You will create a .desktop file as follows:

    [Desktop Entry]
    Version=1.0
    Type=Application
    Exec=epiphany --application-mode=example.desktop https://www.example.com
    Icon=example
    StartupNotify=true
    StartupWMClass=example
    Terminal=false
    Name=Example application
    Comment=A system-wide web application``

Note that the exec line includes a reference to the web app URL and to the .desktop file itself. Store the desktop file and matching icons in the usual locations, for example:

  * For System-Wide:  

    /usr/share/applications/example.desktop
    /usr/share/icons/hicolor/128x128/apps/example.png 

  * For your own user account:

    ~/.local/share/applications/example.desktop
    ~/.local/share/icons/hicolor/128x128/apps/example.png

**__You can also reference local HTML files as follows:__** (( Source: https://wiki.gnome.org/Apps/Web/Docs/FrequentlyAskedQuestions))

    [Desktop Entry]
    Name=Fedora Developer Portal
    Comment=The developer workstation you've been waiting for.
    GenericName=Documentation
    Exec=epiphany --application-mode=fedora-developer-portal.desktop /usr/share/fedora-developer-portal/index.html
    Icon=fedora-developer-portal
    StartupWMClass=fedora-developer-portal
    Type=Application
    StartupNotify=true
    MimeType=text/plain;


----




==== Magic SysRq Key ====
''The Decent Way To Reboot Frozen Kernels.''

  - First, the option within the kernel needs to be turned on.
    - ''sudo sh -c "echo \"1\" > /proc/sys/kernel/sysrq"''
  - Then; the sequence **R** .. **E** .. **K** .. **S** .. **U** .. **B** can be typed slowly while holding ''ALT'' + ''SysRq'' 

== List of SysRq Command Keys  == 
Following are the command keys available for Alt+SysRq+commandkey.(( Source: https://linux.101hacks.com/sysadmin-tasks/magic-sysrq-key/))


  * **‘k’ – Kills all the process running on the current virtual console.** 
  * **’s’ – This will attempt to sync all the mounted file system.**
  * ‘b’ – Immediately reboot the system, without unmounting partitions or syncing.
  * **‘e’ – Sends SIGTERM to all process except init.**
  * ‘m’ – Output current memory information to the console.
  * **‘i’ – Send the SIGKILL signal to all processes except init**
  * ‘r’ – Switch the keyboard from raw mode (the mode used by programs such as X11), to XLATE mode.
  * **’s’ – sync all mounted file system.**
  * ‘t’ – Output a list of current tasks and their information to the console.
  * ‘u’ – Remount all mounted filesystems in readonly mode.
  * ‘o’ – Shutdown the system immediately.
  * ‘p’ – Print the current registers and flags to the console.
  * ‘0-9′ – Sets the console log level, controlling which kernel messages will be printed to your console.
  * **‘f’ – Will call oom_kill to kill process which takes more memory.**
  * ‘h’ – Used to display the help. But any other keys than the above listed will print help.