Programming PHP

}
php_info_print_table_start( );
php_info_print_table_header(2, "rot13 support", "enabled");
php_info_print_table_end( );
When you remove a function (such as RINIT( ) or RSHUTDOWN( )) from rot13.c, be sure
to remove the corresponding prototype from php_rot13.h.
The MINFO( ) function is called by phpinfo( ) and adds whatever information you
want about your extension to the phpinfo( ) output.
Finally, we get to the functions that are callable from PHP. The confirm_rot13_
compiled( ) function exists only to confirm the successful compilation and loading of
the rot13 extension. The skeleton tests use this. Most experienced extension writers
remove the compilation-check function.
Here is the stub function that ext_skel created for our rot13( ) function:
/* {{{ proto string rot13(string arg)
returns the rot13 version of arg */
PHP_FUNCTION(rot13)
{
char *arg = NULL;
int argc = ZEND_NUM_ARGS( );
int arg_len;
if (zend_parse_parameters(argc TSRMLS_CC, "s", &arg, &arg_len)
== FAILURE)
return;
php_error(E_WARNING, "rot13: not yet implemented");
}
/* }}} */
The {{{ proto line is not only used for folding in the editor, but is also parsed by the
genfunclist and genfuncsummary scripts that are part of the PHP documentation
project. If you are never going to distribute your extension and have no ambitions to
have it bundled with PHP, you can remove these comments.
The PHP_FUNCTION( ) macro declares the function. The actual symbol for the function
is zif_rot13, which is useful to know if you are debugging your code and wish to set
a breakpoint.
The only thing the stubbed function does is accept a single string argument and then
issue a warning saying it hasn’t been implemented yet. Here is a complete rot13( )
function:
PHP_FUNCTION(rot13) {
char *arg = NULL, *ch, cap;
int arg_len, i, argc = ZEND_NUM_ARGS( );
if (zend_parse_parameters(argc TSRMLS_CC, "s/", &arg, &arg_len)
== FAILURE)
return;
324 | Chapter 14: Extending PHP
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