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<!--replace-end-7--><!--replace-end-4--><!--replace-end-1--></head><body><div class="ui fluid container universe"><!--replace-start-2--><!--replace-start-3--><!--replace-start-6--><div class="ui text container" id="zettel-container" style="position: relative"><div class="zettel-view"><article class="ui raised attached segment zettel-content"><div class="pandoc"><h1 id="title-h1">Shell sessions</h1><h2 id="types-of-shell-session"><strong>Types of shell session</strong></h2><p>Shell sessions can be one of or several instances of the following types:</p><ul><li><strong>login shell</strong><ul><li>A session that must be authenticated such as when you access remote resources using SSH</li></ul></li><li><strong>non-login shell</strong><ul><li>Not the above</li></ul></li><li><strong>interactive shell</strong><ul><li>A shell session that runs in the terminal and thus that the user can <em>interact</em> with</li></ul></li><li><strong>non-interactive shell</strong><ul><li>A shell session that runs without a terminal</li></ul></li></ul><p>If you are working with a remote server you will be in an <strong>interactive login shell</strong>. If you run a script from the command line you will be in a <strong>non-interactive non-login shell</strong>.</p><h2 id="shell-sessions-and-access">Shell sessions and access</h2><p>The type of shell session that you are currently in affects the <span class="zettel-link-container errors"><span class="zettel-link" title="Wiki-link does not refer to any existing zettel"><a>Environmental-and-shell-variables-04d5ec7e8e2b486a93f002bf686e4bbb</a></span></span> that you can access. This is because the order in which configuration files are read on initialisation differs depending on the type of shell.</p><ul><li>a session defined as a non-login shell will read <code>/etc/bash.bashrc</code> and then the user-specific <code>~/.bashrc</code> file to build its environment.</li><li>A session started as a login session will read configuration details from the <code>/etc/profile</code> file first. It will then look for the first login shell configuration file in the user’s home directory to get user-specific configuration details.</li></ul><p>In Linux, if you want the environmental variable to be accessible from both login and non-login shells, you must put them in <code>~/.bashrc</code></p></div></article><nav class="ui attached segment deemphasized backlinksPane" id="neuron-backlinks-pane"><h3 class="ui header">Backlinks</h3><ul class="backlinks"><li><span class="zettel-link-container cf"><span class="zettel-link"><a href="Expansions_and_substitutions.html">Expansions and substitutions</a></span></span><ul class="context-list" style="zoom: 85%;"><li class="item"><div class="pandoc"><p>Command substitution (circle-brackets) allows us to put the output of one command inside another. Bash runs the bracketed command in a <span class="zettel-link-container cf"><span class="zettel-link" title="Zettel: Shell sessions"><a href="Shell_sessions.html">sub-shell</a></span></span> and then returns it to the main user shell.</p></div></li></ul></li></ul></nav><nav class="ui attached segment deemphasized bottomPane" id="neuron-tags-pane"><div><span class="ui basic label zettel-tag" title="Tag">shell</span></div></nav><nav class="ui bottom attached icon compact inverted menu blue" id="neuron-nav-bar"><!--replace-start-9--><!--replace-end-9--><a class="right item" href="impulse.html" title="Open Impulse"><i class="wave square icon"></i></a></nav></div></div><!--replace-end-6--><!--replace-end-3--><!--replace-end-2--><div class="ui center aligned container footer-version"><div class="ui tiny image"><a href="https://neuron.zettel.page"><img alt="logo" src="https://raw.githubusercontent.com/srid/neuron/master/assets/neuron.svg" title="Generated by Neuron 1.9.35.3" /></a></div></div></div></body></html> |