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imported>Jesstess (Created page with '__NOTOC__ There are three commands that we'll be using at a command prompt to navigate the filesystem on your computer: * <code>ls</code> * <code>pwd</code> * <code>cd</code> <…') |
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__NOTOC__
The filesystem on your computer is like a tree made up of directories and files. The filesystem has a root directory called <tt>/</tt>, and everything on your computer lives in subdirectories of this root directory.
We often navigate the filesystem graphically by clicking on graphical folders. We can do the exact same navigation from the command line.
There are three commands that we'll be using at a command prompt to navigate the filesystem on your computer:
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===Practice using <code>ls</code>, <code>pwd</code>, and <code>cd</code>===
(that's an l the letter, not the number 1)
Type each of these commands and hit enter:
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<br />
===Absolute v. relative paths===
* You can use Tab to auto-complete directory and file names. So from inside the root directory, if you type <code>cd U</code> and hit Tab, the command prompt will auto-complete the directory name as much as it can.▼
When navigating the filesystem, you can use 2 kinds of paths: absolute and relative.
<b>Absolute paths</b>
* An absolute path contains the full set of directories from the root of the file system up to your target file or directory. On OS X, an absolute path starts with <tt>/</tt>.
* You can <tt>cd</tt> to an absolute path from anywhere on the filesystem.
* This is an example absolute path: <tt>/home/jesstess/projects</tt>
<b>Relative paths</b>
* A relative path is calculated relative to your "current working directory" -- the directory you are currently in at a command prompt, as displayed by <tt>pwd</tt>.
* This is an example relative path: <tt>projects</tt>. That path only has meaning given a current working directory. If your current working directory were <tt>/home/jesstess</tt>, then <tt>cd projects</tt> would take you to <tt>/home/jesstess/projects</tt> assuming that such a directory existed. If you were in <tt>/home/brad/Desktop</tt>, then <tt>cd projects</tt> would take you to <tt>/home/brad/Desktop/projects</tt>.
===Tips===
▲* You can use Tab to auto-complete directory and file names. So from inside the root directory <tt>/</tt>, if you type <code>cd
* The command prompt maintains a command history. You can use the up arrow to cycle through old commands.
===Review===
Answer these questions. Experiment at the command line if you need to! If you aren't sure about an answer, ask a helper.
# What directory are you in after starting a new command line prompt?
# After starting a new command line prompt, how would you get to the root directory?
# How do you check what files and directories are in your current working directory?
# If you are in directory <tt>/home</tt>, and you want to get to <tt>/home/jesstess/projects</tt>, how would you do that?
# What are 2 ways to avoid typing out a full navigation command? (hint: one requires that you've run the command before)
# What is the difference between <tt>cd projects</tt> and <tt>cd /projects</tt>?
===Success!===
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You've practiced using <code>ls</code>, <code>pwd</code>, and <code>cd</code> to navigate your computer's filesystem from the command prompt.
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