basic Archives - Complete, Concrete, Concise https://complete-concrete-concise.com/tag/basic/ Practical Information Without The Bloat Tue, 30 Apr 2013 19:59:01 +0000 en-US hourly 1 https://wordpress.org/?v=6.9 Ubuntu 13.04 – Basic Command Line Techniques https://complete-concrete-concise.com/ubuntu-2/ubuntu-13-04/ubuntu-13-04-basic-command-line-techniques/ Tue, 30 Apr 2013 19:59:01 +0000 http://complete-concrete-concise.com/?p=2925 Using the command line doesn't have to be mysterious or hard.

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This tutorial is for Ubuntu 13.04.

It is probably the same for every other version of Ubuntu and all other Linux distros, but I make no guarantee.

Linux (on which Ubuntu is based) is fundamentally a command line driven operating system. While there are graphical interfaces to many of the available commands, sometimes you need (or have no choice) to work at the command line.

There are five fundamental things everyone working at the command line should know (or at least be aware of):

  1. man
  2. pipes
  3. redirection
  4. less (or more)
  5. ls

man

man is short for manual

man is the help file.

When you want to know more about a command, you enter man <command name> to display information about the command. For example:

man ls

will bring up the man page for the command ls. You could also enter man man to display information about the man command. The man page for ls looks something like this:

To navigate through a man you use the following commands:

  • q – exit (quit) the man page
  • SPACE or f – forward to the next page
  • b – backward to the previous page
  • e – forward one line
  • y – backward one line

While there are man pages for pretty much every command, there is no man page for the command cd.

Pipes

Pipes allow you to send the displayed output from one command to another command.

In other words, when you enter a command that displays a bunch of information on the terminal (and maybe scrolls past the top of the terminal), you can use a pipe to send that information to another command.

The most common use of pipes is with the more (or, preferably, less) command. This is especially true when information scrolls past the top of the terminal.

The pipe is the vertical bar (or broken bar) symbol: ‘|‘.

For example, any of the following commands is likely display information that will scroll past the top of the terminal:

ls /bin
ls /etc
ls /lib

If we pipe the output to the more command, then we can scroll through the output one display page at a time:

ls /etc | more

Another common use of pipes is with the grep command. (grep is often used to filter out unwanted information – but I won’t be covering grep here.)

You can pipe together as many commands as you like. The output from the command on the left of the pipe is sent to the command on the right of the pipe.

Redirection

Sometimes you need to capture the information displayed by a command. This is done using redirection.

The output displayed by a command can be sent to a file instead of the display.

The redirection operator is the greater than symbol: ‘>’.

For example, suppose I want to dump a man page to file, so I can later look at (or print that file). I can do so by redirecting the man output to a file (you choose the name of the file):

man ls > ls.txt

The above command will send the output of the man page for ls to a file called ls.txt. I can then handle ls.txt the same way I handle any text file.

Another example, I could send a directory listing to a file as well:

ls > directory_list

The above command will send the output of ls to a file called directory_list. Again, the file can be handled the same way any other text file is handled.

Redirection always send stores the file in the current directory (normally, this will be your /home/<user> directory). You can write the file to another directory by either (1) changing to a different directory (using the cd command), or (2) specifying the path along with the file name. Note: you may not have permission to write in other directories, so the operation will fail.

less

less is an improved version of the more command. The main advantage of using less instead of more is that less lets you scroll backwards through data that has been piped to it; more only allows you to scroll forward through piped data. Other than that difference, less and more behave almost identically.

less is used to display information one page at a time.

Most often it is used in conjunction with pipes to prevent output from scrolling off the top of the terminal:

ls | less

less can be used to display the contents of a text file:

less <file name>

where <file name> is the name of the text file to display.

To navigate through text being displayed by less you use the following commands:

  • q – exit (quit) less
  • SPACE or f – forward to the next page
  • b – backward to the previous page (does not work if more is displaying text from a pipe and the main reason why less is preferred)

    • ls

    ls is short for list

    ls is used to display the contents of a directory.

    Directory contents are colour coded. Different files have different colours.

    The default colours (in the default Ubuntu 13.04 terminal) for common file types are:

    Note: if you or someone has configured your system, or you are using a different terminal (or a different Linux distribution), the colours and their significance may be completely different.

    There are other colour combinations in use and some colours (notably purple) are reused for other file types.

    The post Ubuntu 13.04 – Basic Command Line Techniques appeared first on Complete, Concrete, Concise.

    ]]> Ubuntu 13.04 – Basic Unity Interface / Desktop Tutorial https://complete-concrete-concise.com/ubuntu-2/ubuntu-13-04/ubuntu-13-04-basic-unity-interface-desktop-tutorial/ Tue, 30 Apr 2013 07:26:35 +0000 http://complete-concrete-concise.com/?p=2917 The basics of Unity are easy to pick up.

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    This is a basic tutorial for the Unity Interface / Desktop which comes with Ubuntu 13.04 – it should help get you up and running.

    Each new version of Unity (introduced in 11.04) improves on the functionality of the desktop.

    This tutorial reflects the way I understand and use the Unity interface.

    The Unity interface consists of four main parts:

    1. Panel
    2. Launcher
    3. Dash
    4. HUD

    The Panel

    The Panel is the strip at the top of the interface:

    The menu bar that you are used to seeing near the top of an application’s window is now displayed in the panel:

    There is a catch:

    1. The menus displayed in the Panel are only for the active (topmost) application window.
    2. The menus are only displayed when you hover your mouse over the Panel, otherwise, the Panel is empty.
    3. If a window is maximized (full screen), the buttons (icons) for minimize, maximize, and close are hidden unless you hover your mouse over the panel.

    This might seem like a step backward. Why hide the menu bar? Why make the user have to move the mouse all the way to the panel to access it? While it gives a little extra window space to the application, it is also inefficient – and this was the problem with Unity in Ubuntu 11.04 and 11.10.

    Since Ubuntu 12.04, Unity has the HUD. The HUD makes mousing / navigating through menus obsolete (mostly).

    Additional things displayed in the Panel include:

    • the name of the active (topmost) application (green)
    • various indicators (blue)
    • the time (yellow)
    • the system menu (red)

    The Launcher

    Despite being the most prominent feature of the Unity interface, it is the one I use the least.

    This is the panel of buttons on the left hand side of the screen:

    It serves 3 functions:

    1. Application Launcher: clicking on an icon will launch the application associated with that icon. e.g. Clicking on the FireFox icon launches the FireFox browser.

    2. Visual indicator of running applications: any running application has its icon placed in the Launcher and an indicator showing its status.
      1. Two solid triangles: this is the active application (the one on top).
      2. Single solid triangle: the application is running, but does not have focus (is not on top).
      3. Single open triangle: the application is running in a different workspace (by default, Ubuntu 13.04 sets up only a single workspace. You can read how to enable workspaces here.).

    3. Application Switcher: you can switch to an application (bring it to the front) by clicking on its icon in the Launcher.

    Removing an Application from the Launcher

    Note: removing an application from the Launcher does not uninstall the application.

    The Launcher can become cluttered with applications (when you install an application using the Ubuntu Software Center, it is usually automatically placed in the Launcher).

    1) Right-click on the application you want to remove from the launcher. This will display a popup menu.

    2) Click on Unlock from Launcher in the popup menu:

    Adding an Application to the Launcher

    Sometimes, an application is not added to the Launcher, or you had previously removed it.

    1) Start the application / program you want to add to the Launcher.

    2) Find the application’s icon in the Launcher.

    3) Right-click on the icon. This will display a popup menu.

    4) Click on Lock to Launcher to add the program to the Launcher:

    In general, only the most commonly used applications should be in the launcher.

    Dash

    The Dash replaces searching through menu hierarchies for applications.

    Like anything new, it feels all wrong, but, I found it very easy to pick up and now prefer it over the traditional menu navigating paradigm.

    Instead or navigating a hierarchy of menus, Dash provides a query field in which you type the name of the application or document you want to open.

    Using the Dash interface is very much like searching with Google – as you type in what you are looking for, Dash displays possible results.

    I think the greatest strength of Dash is that you can navigate it completely via the keyboard, so you never alternate between typing and reaching for the mouse.

    Dash is activated by either:

    1) Clicking on the Dash icon in the Launcher:

    2) Tapping the Windows key on your keyboard

    Note: tapping the Windows keys means pressing it as though you intend to type it. It does not mean holding down the key (holding down the key does something else).

    Ubuntu calls this the Super key

    The Dash panel looks something like this (click for a larger image):

    It is divided into upto 5 sections:

    1. The query field (outlined in green) is where the keyboard focus goes when you activate the Dash.

      Type the name of the application you want to run, or document you want to open. As you type, Dash will update the list of applications and documents.

      It has improved greatly since 11.04, if you type in game you will get Mahjong, AisleRiot Solitaire and Freecell Solitaire, and Sudoku.

      I suspect it may still miss certain applications because they are not listed in the “obvious” way. For example, previous versions of Unity would not display Sudoku if you typed in game – you needed to type in puzzle.

      If you type in games it will only display AisleRiot Solitaire, but none of the other games.

    2. A list of the most recently used applications (outlined in red) is displayed. If you type in the query field, the list of applications is modified to match your search.

      You can use your mouse to select an application, or you can use the arrow keys to navigate to the desired application (and then press Enter. I like using the arrow keys because my hands don’t have to leave the keyboard.

    3. A list of the most recent viewed documents (outlined in blue) is displayed. If you type in the query field, the list of documents is modified to match your search.

      You can use your mouse or the arrow keys to navigate and select the desired document. I like using the arrow keys because my hands don’t have to leave the keyboard.

    4. Relevant search results from Amazon (outlined in yellow) . As you type your query, it is sent to Amazon (anonymously via Ubuntu) and relevant results are displayed.

      Many people find this intrusive and disable this feature. Instructions to disable Amazon search results are here.

      I don’t have a problem with it, but wish it was more customizable. For instance, I don’t want Amazon search results in my main Dash panel. I don’t mind them if I am using the music lens or movie lens (explained in more detail below). Unfortunately, there is no way to selectively enable Amazon search results.

    5. At the very bottom of the Dash (shaded in green) are a number of icons. These are “lenses”. A lens is a specifically focussed (or themed) query. The five lenses at the bottom are:

      1. Dash lens: this is the default lens – it searches everything you are possibly connected to which includes your computer as well as any cloud services you use.
      2. Applications lens: this focuses searches only within applications.
      3. Folders and Documents lens: this focuses searches only on folders and documents.
      4. Music lens: focuses search on music.
      5. Photos Lens: focuses search on photos.
      6. Video lens: focuses search on videos.

      You can navigate to the lenses using either the mouse or keyboard.

      Typing Ctrl + Tab will navigate through the lenses.

      Note: typing Ctrl + Tab means, “While holding down the Ctrl key, press the Tab key as though you intend to type it.”

      If you hold the Windows (Super) key down for a few seconds, a cheat sheet of commands will be displayed (click for larger image):

      Note: the cheat sheet only appears if your screen resolution is 1024×768 or greater.

      HUD

      The HUD was introduced in Ubuntu 12.04 and combined with Dash it provides a powerful way of interacting with your applications.

      Just as Dash replaces navigating a hierarchy of menus to find applications and documents, HUD replaces navigating a hierarchy of menus in an application.

      Like anything new, it feels all wrong, but, I found it very easy to pick up and now prefer it over the traditional menu navigating paradigm.

      Instead or navigating a hierarchy of menus, HUD provides a query field in which you type the name of the action you want to perform with your applications.

      Normally, to do something in a program you either use a keyboard shortcut (like Ctrl+B to bold text in a word processor), or you use the mouse to select an option from a menu or toolbar.

      With HUD, you type in what you want to do. The HUD interface will then locate appropriate / matching menu entries and display them to you to select. Again, you can use the mouse to perform the selection or the arrow keys and the Enter key.

      I think the greatest strength of HUD is that you can navigate it completely via the keyboard, so you never alternate between typing and reaching for the mouse.

      The HUD is activated when you tap on the Alt key:

      Note: tapping the Alt keys means pressing it as though you intend to type it. It does not mean holding down the key.

      If you hold the Alt key down for about 2 seconds, the application menu bar will display in the Panel. As soon as yo let go of the Alt key, it will disappear – thus encouraging use of the keyboard to select a menu option (e.g. Alt + F to open the File menu).

      The HUD panel looks something like this:

      1. The query field (outlined in red) is where you type the operation you want to perform in the application, e.g. open, new, auto white balance, etc.

        This is where the focus goes when you activate the HUD.

        As you type, a list of possible commands will be displayed below it. You can navigate those commands using the mouse and clicking to select or the keyboard (arrow keys) and pressing Enter to select. By default, the top command is always selected and will be executed if you press Enter. A nice thing is that you do not have to type the whole command.

        Note: if a command is not available (for example, it is greyed out), then it will not appear in the list of commands.

        For example, if you have just opened GIMP without any image, it is not possible to perform image operations on it (like unsharp mask, or auto color enhance, etc). So if you type unsharp into the query field, you will not receive any options.

        I think it would be better if the HUD somehow indicated that the operation is unavailable rather than just not showing it at all.

      2. On the left, the icon (outlined in green) shows which application the command is for.

        The HUD may display commands for other programs (not just the active one). This can be confusing if you are not paying attention.

      3. Below the query field is a list of matching commands (outlined in blue.

      Note: HUD may not work with all applications – it depends on how the menus in an application were coded. Prior to Ubuntu 13.04, LibreOffice was an application that did not work with the HUD (there was a patch available to make it work, though).

      Final Words

      Unity is a new way of interacting with the computer: instead of navigating a hierarchy of menus, you type what you want to do.

      As an old timer (my first interactions with a computer were via a teletype), I never really liked the mouse / GUI way of doing things because it required me to take one hand off the keyboard. As a consequence, I have always configured shortcut keys to perform common tasks.

      With Unity, I am able to keep my hands on the keyboard and easily perform the tasks I need. I still program my shortcut keys, but I know longer have to navigate through menus to find some lesser used operation.

      Play with it. I think you will find it easy to learn. I have found it easier to adapt to than the Ribbon interface Microsoft introduced a few years ago.

      I find the Dash and HUD work well when I am very familiar with the programs / applications I am working with and I know the command set.

      I find the HUD awkward to work with when I am not familiar with an application. For example, perhaps I install Blender to try out some 3D graphics development. Not being familiar with Blender, it is very awkward to try typing commands into the HUD in the hope of finding the right one. This is definitely a case where being able to browse through a bunch of menus can be helpful.

      Of course, I can always type help and hope a help file comes up.

      It is with new or unfamiliar applications that I miss the menu bar at the top, but even if a menu bar was visible, there have been times when I could not find what I wanted and had to google to discover how it was named or where it was located.

      Additional Resources

      While these aren’t tutorials, they offer some insight into Canonical’s focus and direction (they are written by Mark Shuttleworth – Canonical’s CEO):

      Introducing the HUD. Say hello to the future of the menu.

      Dash takes shape for 11.10 Unity (note: the Dash panel has changed somewhat from the screen capture he presents)

      This shows a side by side comparison between using the tradition menu driven way to perform a task and using HUD. While a number of commenters have complained that it isn’t an objective comparison, I think it shows very nicely the difference in working in both environments:

      This is another video showing the HUD In action:

      The post Ubuntu 13.04 – Basic Unity Interface / Desktop Tutorial appeared first on Complete, Concrete, Concise.

      ]]> Ubuntu 12.04 – Basic Command Line Techniques https://complete-concrete-concise.com/ubuntu-2/ubuntu-12-04/ubuntu-12-04-basic-command-line-techniques/ Thu, 13 Dec 2012 14:57:21 +0000 http://complete-concrete-concise.com/?p=2598 This tutorial is for Ubuntu 12.04. It should be the same for every other version of Ubuntu and all other Linux distros, but I make no guarantee. Linux (on which Ubuntu is based) is fundamentally a command line driven operating system. While there are graphical interfaces to many of the available commands, sometimes you need […]

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      This tutorial is for Ubuntu 12.04.

      It should be the same for every other version of Ubuntu and all other Linux distros, but I make no guarantee.

      Linux (on which Ubuntu is based) is fundamentally a command line driven operating system. While there are graphical interfaces to many of the available commands, sometimes you need (or have no choice) to work at the command line.

      There are five fundamental things everyone working at the command line should know (or at least be aware of):

      1. man
      2. pipes
      3. redirection
      4. more
      5. ls

      man

      man is short for manual

      man is the help file.

      When you want to know more about a command, you enter man <command name> to display information about the command. For example:

      man ls

      will bring up the man page for the command ls. You could also enter man man to display information about the man command. The man page for ls looks something like this:

      To navigate through a man you use the following commands:

      • q – exit (quit) the man page
      • SPACE or f – forward to the next page
      • b – backward to the previous page
      • e – forward one line
      • y – backward one line

      For some reason, there is no man page for the command cd.

      Pipes

      Pipes allow you to send the displayed output from one command to another command.

      In other words, when you enter a command that displays a bunch of information on the terminal (and maybe scrolls past the top of the terminal), you can use a pipe to send that information to another command.

      The most common use of pipes is with the more command. This is especially true when information scrolls past the top of the terminal.

      The pipe is the vertical bar (or broken bar) symbol: ‘|‘.

      For example, any of the following commands is likely display information that will scroll past the top of the terminal:

      ls /bin
ls /etc
ls /lib

      If we pipe the output to the more command, then we can scroll through the output one display page at a time:

      ls /etc | more

      Another common use of pipes is with the grep command. (grep is often used to filter out unwanted information – but I won’t be covering grep here.)

      You can pipe together as many commands as you like. The output from the command on the left of the pipe is sent to the command on the right of the pipe.

      Redirection

      Sometimes you need to capture the information displayed by a command. This is done using redirection.

      The output displayed by a command can be sent to a file instead of the display.<./p>

      The redirection operator is the greater than symbol: ‘&gt’.

      For example, suppose I want to dump a man page to file, so I can later look at (or print that file). I can do so by redirecting the man output to a file (you choose the name of the file):

      man ls > ls.txt

      The above command will send the output of the man page for ls to a file called ls.txt. I can then handle ls.txt the same way I handle any text file.

      Another example, I could send a directory listing to a file as well:

      ls > directory_list

      The above command will send the output of ls to a file called directory_list. Again, the file can be handled the same way any other text file is handled.

      Redirection always send stores the file in the current directory (normally, this will be your /home/<user> directory). You can write the file to another directory by either (1) changing to a different directory (using the cd command), or (2) specifying the path along with the file name. Note: you may not have permission to write in other directories, so the operation will fail.

      more

      more is used to display information one page at a time.

      Most often it is used in conjunction with pipes to prevent output from scrolling off the top of the terminal:

      ls | more

      more can be used to display the contents of a text file:

      more <file name>

      where <file name> is the name of the text file to display.

      To navigate through text being displayed by more you use the following commands:

      • q – exit (quit) more
      • SPACE or f – forward to the next page
      • b – backward to the previous page (does not work if more is displaying text from a pipe)

        • There is a slightly more useful command called less that allows you to scroll forwards and backwards through piped information. Aside from that difference less behaves very much like more.

        You can use man less to learn about the less command

        ls

        ls is short for list

        ls is used to display the contents of a directory.

        Directory contents are colour coded. Different files have different colours.

        The default colours (in the default Ubuntu 12.04 terminal) for common file types are:

        There are other colour combinations in use and some colours (notably purple) are reused for other file types.

        The post Ubuntu 12.04 – Basic Command Line Techniques appeared first on Complete, Concrete, Concise.

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