2 =============================================================================
4 HOW TO CREATE A SELF-CONTAINED PHP EXTENSION
6 A self-contained extension can be distributed independently of
7 the PHP source. To create such an extension, two things are
10 - Configuration file (config.m4)
11 - Source code for your module
13 We will describe now how to create these and how to put things
18 While the result will run on any system, a developer's setup needs these
26 All of these are available from
28 ftp://ftp.gnu.org/pub/gnu/
30 CONVERTING AN EXISTING EXTENSION
32 Just to show you how easy it is to create a self-contained
33 extension, we will convert an embedded extension into a
34 self-contained one. Install PHP and execute the following
40 You now have an empty directory. We will copy the files from
43 $ cp -rp php-4.0.X/ext/mysql/* .
45 It is time to finish the module. Run:
49 You can now ship the contents of the directory - the extension
50 can live completely on its own.
52 The user instructions boil down to
55 [--with-php-config=/path/to/php-config] \
56 [--with-mysql=MYSQL-DIR]
59 The MySQL module will either use the embedded MySQL client
60 library or the MySQL installation in MYSQL-DIR.
63 DEFINING THE NEW EXTENSION
65 Our demo extension is called "foobar".
67 It consists of two source files "foo.c" and "bar.c"
68 (and any arbitrary amount of header files, but that is not
71 The demo extension does not reference any external
72 libraries (that is important, because the user does not
73 need to specify anything).
76 LTLIBRARY_SOURCES specifies the names of the sources files. You can
77 name an arbitrary number of source files here.
79 CREATING THE M4 CONFIGURATION FILE
81 The m4 configuration can perform additional checks. For a
82 self-contained extension, you do not need more than a few
85 ------------------------------------------------------------------------------
86 PHP_ARG_ENABLE(foobar,whether to enable foobar,
87 [ --enable-foobar Enable foobar])
89 if test "$PHP_FOOBAR" != "no"; then
90 PHP_NEW_EXTENSION(foobar, foo.c bar.c, $ext_shared)
92 ------------------------------------------------------------------------------
94 PHP_ARG_ENABLE will automatically set the correct variables, so
95 that the extension will be enabled by PHP_NEW_EXTENSION in shared mode.
97 The first argument of PHP_NEW_EXTENSION describes the name of the
98 extension. The second names the source-code files. The third passes
99 $ext_shared which is set by PHP_ARG_ENABLE/WITH to PHP_NEW_EXTENSION.
101 Please use always PHP_ARG_ENABLE or PHP_ARG_WITH. Even if you do not
102 plan to distribute your module with PHP, these facilities allow you
103 to integrate your module easily into the main PHP module framework.
105 CREATING SOURCE FILES
107 ext_skel can be of great help when creating the common code for all modules
108 in PHP for you and also writing basic function definitions and C code for
109 handling arguments passed to your functions. See README.EXT_SKEL for further
112 As for the rest, you are currently alone here. There are a lot of existing
113 modules, use a simple module as a starting point and add your own code.
116 CREATING THE SELF-CONTAINED EXTENSION
118 Put config.m4 and the source files into one directory. Then, run phpize
119 (this is installed during make install by PHP 4.0).
121 For example, if you configured PHP with --prefix=/php, you would run
125 This will automatically copy the necessary build files and create
126 configure from your config.m4.
128 And that's it. You now have a self-contained extension.
130 INSTALLING A SELF-CONTAINED EXTENSION
132 An extension can be installed by running:
135 [--with-php-config=/path/to/php-config]
138 ADDING SHARED MODULE SUPPORT TO A MODULE
140 In order to be useful, a self-contained extension must be loadable
141 as a shared module. I will explain now how you can add shared module
142 support to an existing module called foo.
144 1. In config.m4, use PHP_ARG_WITH/PHP_ARG_ENABLE. Then you will
145 automatically be able to use --with-foo=shared[,..] or
146 --enable-foo=shared[,..].
148 2. In config.m4, use PHP_NEW_EXTENSION(foo,.., $ext_shared) to enable
149 building the extension.
151 3. Add the following lines to your C source file:
153 #ifdef COMPILE_DL_FOO