Publishers of technology books, eBooks, and videos for creative people

Home > Articles

This chapter is from the book

Exercise 4.1 Command-Line Navigation

In this exercise, you use commands to navigate the file system, to view items that aren’t visible from the Finder, and to access the manual (man) pages that tell you more about commands.

View Your Home Folder

  1. If necessary, log in as Local Administrator.

  2. Click Launchpad in the Dock.

  3. In the Search field at the top of the screen, enter Terminal.

  4. Click Terminal.

    A new Terminal window opens.

    The second line you see includes your computer and user name followed by a prompt—for example:

    Mac-17:~ ladmin$

    In this example, Mac-17 is the name of the Mac you logged in to. The colon separates the computer name from the path to your current working directory. The path is ~ (the tilde [~] is shorthand for your home folder). After the space, you see the name of the logged-in user. The $ is the prompt.

  5. At the prompt, type ls and press Return.

    You will see output that looks something like this, followed by another prompt:

    Desktop     Downloads           Movies   Pictures
    Documents   Library   Music    Public
  6. Switch to the Finder. If you don’t see a Finder window that’s open, go to File > New Finder Window or press Command-N.

  7. Select ladmin’s home folder in the Finder sidebar and compare the contents of the home folder in the Finder and Terminal.

    With the exception of the Library folder, what you see in Terminal is the same as in the Finder. (User Library folders are hidden in the Finder by default; see Reference 14.1, “Examine Hidden Items.”)

  8. Switch back to Terminal and type ls -A (lowercase LS followed by space, a hyphen, and an uppercase A) at the prompt.

    In general, the command-line environment is case-sensitive. For example, ls –a isn’t the same as ls -A.

    You will see some extra files in the list that begin with a period. Files beginning with a period are hidden in directory listings unless you ask for them by entering ls -A. The Finder doesn’t show files beginning with a period (sometimes called dot-files).

Examine and Change Your Current Working Directory

Think of your current working directory as the place you are in the file system. When you open a new Terminal window, your default working directory is your home folder. Use the cd command to change your current working directory.

  1. At the prompt, type pwd.

    The period (.) ends the sentence and isn’t part of the command, so don’t type it. This guide tells you if a trailing “.” is part of the command. Also, press Return at the end of each step, unless otherwise instructed.

    You will see:

    /Users/ladmin

    This is where Local Administrator’s home folder exists in the file system. It’s the folder you’re “in” in this Terminal window.

  2. At the prompt, type cd Library.

    This changes your current working directory to the Library folder inside your home folder.

    This command uses a relative path. A relative path means “Start in my current working directory.”

    Your prompt changes to something like this:

    Mac-17:Library ladmin$

    The path component of the prompt indicates the folder you are in, not the entire path.

    The cd command changed your working directory without providing feedback. A command that completes and doesn’t need to provide feedback will exit silently. If you get an error message, you should investigate its cause before continuing.

  3. At the prompt, type pwd. Terminal displays:

    /Users/ladmin/Library

    You changed to the Library folder that was inside your previous working directory.

  4. Type ls to view what files and folders are in this Library folder.

  5. At the prompt, type cd /Library. Note the / that precedes Library this time.

  6. At the prompt, type pwd. You will see output like this:

    /Library

    This is a different folder.

    A path that starts with a leading / is an absolute path. It means “Start at the root folder and navigate from there.” A path that doesn’t start with a leading / is a relative path. It means “Start in your current working directory and navigate from there.”

  7. Enter ls to view the files and folders that are in this Library folder.

    There is some overlap in the item names in this Library and the one in ladmin’s home folder, but the names aren’t entirely the same.

  8. At the prompt, type cd and a space character. Don’t press the Return key.

    Terminal enables you to drag and drop items from the Finder to Terminal and have the path to the items appear in the command line.

    In this part of the exercise, you use the Finder to locate a folder you want to use as your working directory in Terminal.

  9. Switch to the Finder.

    When you don’t know exactly what you are looking for, it’s sometimes faster and easier to find a file or folder in the Finder.

  10. Open a new Finder window if necessary.

  11. Click Macintosh HD in the sidebar.

  12. Open the Users folder.

  13. Drag and drop the Shared folder to Terminal.

    Terminal fills in the path (/Users/Shared). Macintosh HD doesn’t appear in the path that Terminal fills in.

    The Finder shows you volume names to make locating a particular volume easier. Terminal doesn’t show volume names in the same way.

  14. Switch to Terminal and press Return.

  15. Type pwd at the prompt.

    You are in the Shared folder.

Read About ls in the Man Pages

In Terminal, you can read the details about commands using the man command.

  1. Open Terminal.

  2. At the prompt, type man ls.

    This opens the man page for the ls command.

    Each man page is divided into various parts. The number in parentheses on the top line indicates in which section of the manual this command is documented. In this case, ls is documented in section 1, which is for general use commands. Next you see the name of the command and a very terse summary of what the command does: “list directory contents.” The synopsis is supposed to be a formal representation of how to use the command. Anything contained in square brackets is optional. The synopsis isn’t always completely accurate. For example, a few options for ls are mutually exclusive of each other, but this synopsis does not indicate that. Generally speaking, options or switches (which change the behavior of a command) immediately follow the command, and arguments (which tell the command what to operate on) follow options or switches. The description, which describes the various uses of the command, follows the synopsis.

  3. Press the Q key to quit viewing the man page for ls.

  4. At the prompt, type man less.

    The less option enables you to view one man page at a time.

  5. Use the Space bar to read through the man pages one page at a time.

  6. After you’re comfortable with the less option, read the ls man page.

  7. At the prompt, enter man man.

  8. Read about the man command.

    You can also Control-click, or on a MacBook Pro with Touch Bar, tap the icon for a man page to open it.

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Peachpit products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email ask@peachpit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.peachpit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020