Learning PHP

What Is This?

This is the example code that from Learning PHP by David Sklar.

See an error? Report it here, or simply fork and send us a pull request.

If you want a copy of all of the example code snippets in this repo, lick the Download Zip button to the right to download everything.

How do I use this code?

Each subdirectory in the display-code directory corresponds to one chapter of the book. Each chapter directory has a toc.txt file that lists the files in the directory in the order they appear in the book. The first column in toc.txt lists the example number of the piece of code (if any). The second column is the filename. For example, net/toc.txt begins as follows:

1	fgc-get.php
-	fgc-get.out
2	fgc-query-params.php
-	fgc-query-params.out

This means that the contents of Example 11-1 are in net/fgc-get.php. The next code excerpt that appears in the book isn't PHP code, but showing the output of a program. That's in net/fgc-get.out. Then comes Example 11-2, whose contents you can find in net/fgc-query-params.php, and then what's in net/fgc-query-params.out.

The files under display-code are useful because they mirror exactly what appears in the book but they are not directly runnable for a number of reasons -- most don't include <?php PHP start tags and lots of them depend on other files that contain necessary code to be included.

The code directory provides runnable versions of each code snippet. It is organized the same way (with the same toc.txt files). The runner.php program runs one or more code examples. runner.php --help tells you how to use it:

runner.php [--chapter=CHAPTER] [--code=CODE] [--bare] [--fail-first] [--ignore-net-fail] [--cli=CLI]

Runs one or more code examples and reports on success/failure.

  --chapter=CHAPTER     Run code examples from chapter CHAPTER
  --code=CODE           Run code example CODE
  --cli=CLI             Use PHP binary installed at CLI
  --bare                Just run the code, don't report on success/failure
  --fail-first          Exit after first code failure
  --ignore-net-fail     Ignore failures that seem to be from a lack of network

PHP binary configured to run code examples:
   /usr/local/bin/php

--chapter and --code and each be specified more than once.

CHAPTER and CODE are interpreted as shell globs.

CHAPTER should just be the name of a chapter file without
extension, e.g. "datetime".

CODE should be the name of a chapter code directory, then /,
then the basename of the code example, e.g. "datetime/interval"

For example, you can try runner.php --code=datetime/interval or runner.php --chapter=datetime. runner.php depends on a few things installable by Composer. Run composer install from the same directory that runner.php is in to install them. A lot of the code examples depend on other things installed by Composer as well. Run composer install from the code subdirectory to install them.

Normally, runner.php runs a code snippet and checks that it emitted the correct output (or the expected errors, if the code snippet is illustrating some error scenario). runner.php employs a number of auxiliary files to determine the expected output or errors and settings to use when running the code.

For a given code example in, say, code/some-chapter/some-code.php, the following additional files control the behavior of runner.php:

Files that control expected output or error output

Files that control settings that are active when running the code

Other files that do things

*.out and *.err can also contain a few special things to make matching expected output easier. The string {{*}} in *.out or *.err matches the full path to the executing code file. The string {{d}} matches the directory of the executing code file (with a trailing /). The string {{!}} matches any path starting with /.

If you want runner.php to run a piece of code and not check the expected output/errors, provide the --bare commandline argument. That still uses the various files to set ini values, args, and so forth, but then just outputs anything the code snippet does instead of checking to see if it matches expected values.

Special Things to Note About Running Code Snippets

Some the code snippets in the datetime directory use libfaketime and .faketime files to specify that the system time should be a certain value when running the code snippet. This makes for predictable output that can be checked. If you want this to work, install libfaketime. If libfaketime is not present, runner.php will just skip the snippets that require it.

Some of the code snippets in the net directory use php7.example.com as a hostname for a server to connect to. This is not a real, functioning server name. The "server" in question is another script started by runner.php because of a *.server files. To make these code snippets function properly, you need to tell your computer to map the hostname php7.example.com to your computer. One way to do this is to add a line such as the following to your /etc/hosts file:

127.0.0.1	localhost  php7.example.com