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| 9 | </head> |
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| 10 | <body> |
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| 11 | <div id="TOC"> |
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| 12 | <ul> |
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| 13 | <li><a href="#screen-primer"><span class="toc-section-number">1</span> screen primer</a><ul> |
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| 14 | <li><a href="#introduction"><span class="toc-section-number">1.1</span> Introduction</a></li> |
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| 15 | <li><a href="#show-existing-screen-sessions"><span class="toc-section-number">1.2</span> Show existing screen sessions</a></li> |
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| 16 | <li><a href="#start-a-new-session"><span class="toc-section-number">1.3</span> Start a new session</a></li> |
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| 17 | <li><a href="#working-with-your-session"><span class="toc-section-number">1.4</span> Working with your session</a></li> |
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| 18 | </ul></li> |
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| 19 | <li><a href="#command-mode-cheat-sheet"><span class="toc-section-number">2</span> Command mode cheat sheet</a></li> |
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| 20 | </ul> |
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| 21 | </div> |
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| 22 | <h1 id="screen-primer"><a href="#screen-primer"><span class="header-section-number">1</span> screen primer</a></h1> |
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| 23 | <h2 id="introduction"><a href="#introduction"><span class="header-section-number">1.1</span> Introduction</a></h2> |
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| 24 | <p>Screen is a window manager for text terminals. It's very useful for managing your virtual environment, particularly when you are teaching with other instructors.</p> |
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| 25 | <p>Ansible installed a .screenrc configuration file onto your server and we'll assume that you are using the NSRC's custom screen configuration for these exercises.</p> |
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| 26 | <p>You'll start a screen session from the command line. It's good practice to check what sessions are currently running on your server before starting a new one.</p> |
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| 27 | <h2 id="show-existing-screen-sessions"><a href="#show-existing-screen-sessions"><span class="header-section-number">1.2</span> Show existing screen sessions</a></h2> |
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| 28 | <p>Ssh to your server:</p> |
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| 29 | <pre><code>$ ssh nsrc@s1.ws.nsrc.org</code></pre> |
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| 30 | <p>List any existing screen sessions:</p> |
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| 31 | <pre><code> $ screen -ls</code></pre> |
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| 32 | <p>There shouldn't be any screen sessions.</p> |
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| 33 | <h2 id="start-a-new-session"><a href="#start-a-new-session"><span class="header-section-number">1.3</span> Start a new session</a></h2> |
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| 34 | <p>Now that you've confirmed that there are no sessions, create a new screen session named <em>workshopX</em> (e.g. workshop1, workshop2, workshop3). Agree with your partners what you will name your sessions. Each person should pick a unique session name in your group.</p> |
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| 35 | <pre><code>$ screen -S workshopX </code></pre> |
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| 36 | <p>You should see the status bar at the bottom of your screen with 3 windows named shell1, shell2, and shell3. You can also list your session and those of your partners with:</p> |
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| 37 | <pre><code>$ screen -ls</code></pre> |
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| 38 | <h2 id="working-with-your-session"><a href="#working-with-your-session"><span class="header-section-number">1.4</span> Working with your session</a></h2> |
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| 39 | <p>You have 3 windows in your session. Let's create a new window. Type <strong>C-x C-c</strong> to create the new window. It will be named <em>bash</em>.</p> |
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| 40 | <p>Let's give it a more useful name. Type <strong>C-x A</strong> (this is case-sensitive) and you'll see the following prompt at the bottom of your screen:</p> |
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| 41 | <p><code>Set window's title to:</code></p> |
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| 42 | <p>Delete <em>bash</em> and name your new window <strong>compile</strong>. The status bar at the bottom of your screen will be updated when you hit return.</p> |
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| 43 | <p>Now navigate to a new window with <strong>C-x n</strong>. You can return to the previous window with <strong>C-x p</strong>.</p> |
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| 44 | <p>Next navigate to the window labeled "shell2" and kill it with <strong>C-x k</strong>. Then type <strong>y</strong> to confirm that you want to kill the current window.</p> |
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| 45 | <p>Let's start a program that will update continously:</p> |
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| 46 | <pre><code>$ watch --interval 1 date</code></pre> |
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| 47 | <p>Finally detach from your session with <strong>C-x d</strong>.</p> |
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| 48 | <p>Now you will connect to one of your partner's screen sessions. You should be at the command line and not in a screen session. If your partner created a session named workshop2, you would use</p> |
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| 49 | <pre><code>$ screen -r -d workshop2</code></pre> |
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| 50 | <p>Navigate through the windows until you find the one running the <code>watch --interval 1 date</code> command. Kill the process by typing <strong>C-c</strong> and then detach from your partner's session with <strong>C-x d</strong>.</p> |
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| 51 | <h1 id="command-mode-cheat-sheet"><a href="#command-mode-cheat-sheet"><span class="header-section-number">2</span> Command mode cheat sheet</a></h1> |
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| 52 | <p>C == Control</p> |
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| 53 | <p>Screen's default command sequence is C-a. We've redefined this as C-x because C-a is used by other programs, most importantly bash command line editing.</p> |
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| 54 | <p><strong>C-x C-c</strong> <em>new window</em></p> |
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| 55 | <p><strong>C-x A</strong> <em>name window</em></p> |
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| 56 | <p><strong>C-x k</strong> <em>kill window</em></p> |
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| 57 | <p><strong>C-x d</strong> <em>detach from session</em></p> |
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| 58 | <p><strong>C-x n,p</strong> <em>next or previous window</em></p> |
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| 59 | <p><strong>C-x 1,2,3</strong> <em>move to specific window</em></p> |
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| 60 | <p><strong>C-x ESC</strong> <em>enter scrollback mode</em></p> |
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| 61 | </body> |
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| 62 | </html> |
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