(NOTE: you may also want to take a look at the pear package PECL_Gen, a PHP-only alternative for this script that supports way more extension writing tasks and is supposed to replace ext_skel completely in the long run ...) WHAT IT IS It's a tool for automatically creating the basic framework for a PHP module and writing C code handling arguments passed to your functions from a simple configuration file. See an example at the end of this file. HOW TO USE IT Very simple. First, change to the ext/ directory of the PHP 4 sources. If you just need the basic framework and will be writing all the code in your functions yourself, you can now do ./ext_skel --extname=module_name and everything you need is placed in directory module_name. [ Note that GNU awk is likely required for this script to work. Debian systems seem to default to using mawk, so you may need to change the #! line in skeleton/create_stubs and the cat $proto | awk line in ext_skel to use gawk explicitly. ] If you don't need to test the existence of any external header files, libraries or functions in them, the module is already almost ready to be compiled in PHP. Just remove 3 comments in your_module_name/config.m4, change back up to PHP sources top directory, and do ./buildconf; ./configure --enable-module_name; make The definition of PHP_MODULE_NAME_VERSION will be present in the php_module_name.h and injected into the zend_module_entry definition. This is required by the PECL website for the version string conformity checks against package.xml But if you already have planned the overall scheme of your module, what functions it will contain, their return types and the arguments they take (a very good idea) and don't want to bother yourself with creating function definitions and handling arguments passed yourself, it's time to create a function definitions file, which you will give as an argument to ext_skel with option --proto=filename. SOURCE AND HEADER FILE NAME ./ext_skel generates 'module_name.c' and 'php_module_name.h' as main source and header files. Keep these names. Module functions (User functions) must be named module_name_function() When you need to expose module functions to other modules, expose functions strictly needed by others. Exposed internal function must be named php_module_name_function() See also CODING_STANDARDS. FORMAT OF FUNCTION DEFINITIONS FILE All the definitions must be on one line. In it's simplest form, it's just the function name, e.g. module_name_function but then you'll be left with an almost empty function body without any argument handling. Arguments are given in parenthesis after the function name, and are of the form 'argument_type argument_name'. Arguments are separated from each other with a comma and optional space. Argument_type can be one of int, bool, double, float, string, array, object or mixed. An optional argument is separated from the previous by an optional space, then '[' and of course comma and optional space, like all the other arguments. You should close a row of optional arguments with same amount of ']'s as there where '['s. Currently, it does not harm if you forget to do it or there is a wrong amount of ']'s, but this may change in the future. An additional short description may be added after the parameters. If present it will be filled into the 'proto' header comments in the stubs code and the tag in the XML documentation. An example: module_name_function(int arg1, int arg2 [, int arg3 [, int arg4]]) Arguments arg1 and arg2 are required. Arguments arg3 and arg4 are optional. If possible, the function definition should also contain it's return type in front of the definition. It's not actually used for any C code generating purposes but PHP in-source documentation instead, and as such, very useful. It can be any of int, double, string, bool, array, object, resource, mixed or void. The file must contain nothing else but function definitions, no comments or empty lines. OTHER OPTIONS --no-help By default, ext_skel creates both comments in the source code and a test function to help first time module writers to get started and testing configuring and compiling their module. This option turns off all such things which may just annoy experienced PHP module coders. Especially useful with --stubs=file which will leave out also all module specific stuff and write just function stubs with function value declarations and passed argument handling, and function entries and definitions at the end of the file, for copying and pasting into an already existing module. --xml[=file] Creates the basics for phpdoc .xml file. --full-xml Not implemented yet. When or if there will ever be created a framework for self-contained extensions to use phpdoc system for their documentation, this option enables it on the created xml file. CURRENT LIMITATIONS, BUGS AND OTHER ODDITIES Only arguments of types int, bool, double, float, string and array are handled. For other types you must write the code yourself. And for type mixed, it wouldn't even be possible to write anything, because only you know what to expect. It can't handle correctly, and probably never will, variable list of of arguments. (void foo(int bar [, ...]) Don't trust the generated code too much. It tries to be useful in most of the situations you might encounter, but automatic code generation will never beat a programmer who knows the real situation at hand. ext_skel is generally best suited for quickly generating a wrapper for c-library functions you might want to have available in PHP too. This program doesn't have a --help option. It has --no-help instead. EXAMPLE The following _one_ line bool module_name_drawtext(resource image, string text, resource font, int x, int y [, int color]) will create this function definition for you (note that there are a few question marks to be replaced by you, and you must of course add your own value definitions too): /* {{{ proto bool module_name_drawtext(resource image, string text, resource font, int x, int y [, int color]) */ PHP_FUNCTION(module_name_drawtext) { char *text = NULL; int argc = ZEND_NUM_ARGS(); int image_id = -1; size_t text_len; int font_id = -1; zend_long x; zend_long y; zend_long color; zval *image = NULL; zval *font = NULL; if (zend_parse_parameters(argc, "rsrll|l", &image, &text, &text_len, &font, &x, &y, &color) == FAILURE) return; if (image) { ZEND_FETCH_RESOURCE(???, ???, image, image_id, "???", ???_rsrc_id); } if (font) { ZEND_FETCH_RESOURCE(???, ???, font, font_id, "???", ???_rsrc_id); } php_error(E_WARNING, "module_name_drawtext: not yet implemented"); } /* }}} */