1$Id$
2=============================================================================
3
4HOW TO CREATE A SELF-CONTAINED PHP EXTENSION
5
6  A self-contained extension can be distributed independently of
7  the PHP source. To create such an extension, two things are
8  required:
9
10  - Configuration file (config.m4)
11  - Source code for your module
12
13  We will describe now how to create these and how to put things
14  together.
15
16PREPARING YOUR SYSTEM
17
18  While the result will run on any system, a developer's setup needs these
19  tools:
20
21    GNU autoconf
22    GNU automake
23    GNU libtool
24    GNU m4
25
26  All of these are available from
27
28    ftp://ftp.gnu.org/pub/gnu/
29
30CONVERTING AN EXISTING EXTENSION
31
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
35  commands.
36
37     $ mkdir /tmp/newext
38     $ cd /tmp/newext
39
40  You now have an empty directory. We will copy the files from
41  the mysql extension:
42
43     $ cp -rp php-4.0.X/ext/mysql/* .
44
45  It is time to finish the module. Run:
46
47     $ phpize
48
49  You can now ship the contents of the directory - the extension
50  can live completely on its own.
51
52  The user instructions boil down to
53
54     $ ./configure \
55            [--with-php-config=/path/to/php-config] \
56            [--with-mysql=MYSQL-DIR]
57     $ make install
58
59  The MySQL module will either use the embedded MySQL client
60  library or the MySQL installation in MYSQL-DIR.
61
62
63DEFINING THE NEW EXTENSION
64
65  Our demo extension is called "foobar".
66
67  It consists of two source files "foo.c" and "bar.c"
68  (and any arbitrary amount of header files, but that is not
69  important here).
70
71  The demo extension does not reference any external
72  libraries (that is important, because the user does not
73  need to specify anything).
74
75
76  LTLIBRARY_SOURCES specifies the names of the sources files. You can
77  name an arbitrary number of source files here.
78
79CREATING THE M4 CONFIGURATION FILE
80
81  The m4 configuration can perform additional checks. For a
82  self-contained extension, you do not need more than a few
83  macro calls.
84
85------------------------------------------------------------------------------
86PHP_ARG_ENABLE(foobar,whether to enable foobar,
87[  --enable-foobar            Enable foobar])
88
89if test "$PHP_FOOBAR" != "no"; then
90  PHP_NEW_EXTENSION(foobar, foo.c bar.c, $ext_shared)
91fi
92------------------------------------------------------------------------------
93
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.
96
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.
100
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.
104
105CREATING SOURCE FILES
106
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
110  information.
111
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.
114
115
116CREATING THE SELF-CONTAINED EXTENSION
117
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).
120
121  For example, if you configured PHP with --prefix=/php, you would run
122
123     $ /php/bin/phpize
124
125  This will automatically copy the necessary build files and create
126  configure from your config.m4.
127
128  And that's it. You now have a self-contained extension.
129
130INSTALLING A SELF-CONTAINED EXTENSION
131
132  An extension can be installed by running:
133
134     $ ./configure \
135            [--with-php-config=/path/to/php-config]
136     $ make install
137
138ADDING SHARED MODULE SUPPORT TO A MODULE
139
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.
143
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[,..].
147
148  2. In config.m4, use PHP_NEW_EXTENSION(foo,.., $ext_shared) to enable
149     building the extension.
150
151  3. Add the following lines to your C source file:
152
153        #ifdef COMPILE_DL_FOO
154        ZEND_GET_MODULE(foo)
155        #endif
156
157PECL SITE CONFORMITY
158
159  If you plan to release an extension to the PECL website, there are several
160  points to be regarded.
161
162 1. Add LICENSE or COPYING to the package.xml
163
164 2. The following should be defined in one of the extension header files
165
166        #define PHP_FOO_VERSION "1.2.3"
167
168    This macros has to be used within your foo_module_entry to indicate the
169    extension version.
170
171