How FFI::cdef() Parses C Declarations
The FFI::cdef() method in PHP plays a crucial role in allowing you to interact with native C libraries directly from your PHP code. Its primary function is to parse C declarations that you provide as a string, such as function signatures, struct definitions, and type declarations. When you call FFI::cdef(), PHP reads the C code you supply, checks it for correct C syntax, and constructs internal representations of the declared functions and types. This process allows PHP to expose those C functions and structures as callable objects or types within your PHP script at runtime.
For example, if you want to use a simple C function like int add(int, int), you must provide an accurate C declaration to FFI::cdef(). PHP then parses this declaration, creates a mapping between the PHP and C types, and enables you to call the function as if it were a native PHP method. Internally, PHP maintains metadata about the function's name, its argument types, and its return type, ensuring that calls from PHP are correctly marshaled to the underlying C implementation.
ffi_add_example.php
12345678910111213<?php // Declare and use a simple C function via FFI::cdef() // C declaration string for a simple add function $c_code = "int add(int a, int b);"; // Load the shared library (libadd.so must export 'add') $ffi = FFI::cdef($c_code, "libadd.so"); // Call the C function from PHP $result = $ffi->add(2, 3); echo "2 + 3 = " . $result . "\n";
A common mistake when using FFI::cdef() is failing to match the C declaration syntax exactly. For instance, forgetting a semicolon at the end of a declaration or specifying an incorrect type will cause PHP to throw a parse error. Always double-check your C declaration strings for proper syntax to avoid these issues.
Дякуємо за ваш відгук!
Запитати АІ
Запитати АІ
Запитайте про що завгодно або спробуйте одне із запропонованих запитань, щоб почати наш чат
Чудово!
Completion показник покращився до 11.11How FFI::cdef() Parses C Declarations
Свайпніть щоб показати меню
The FFI::cdef() method in PHP plays a crucial role in allowing you to interact with native C libraries directly from your PHP code. Its primary function is to parse C declarations that you provide as a string, such as function signatures, struct definitions, and type declarations. When you call FFI::cdef(), PHP reads the C code you supply, checks it for correct C syntax, and constructs internal representations of the declared functions and types. This process allows PHP to expose those C functions and structures as callable objects or types within your PHP script at runtime.
For example, if you want to use a simple C function like int add(int, int), you must provide an accurate C declaration to FFI::cdef(). PHP then parses this declaration, creates a mapping between the PHP and C types, and enables you to call the function as if it were a native PHP method. Internally, PHP maintains metadata about the function's name, its argument types, and its return type, ensuring that calls from PHP are correctly marshaled to the underlying C implementation.
ffi_add_example.php
12345678910111213<?php // Declare and use a simple C function via FFI::cdef() // C declaration string for a simple add function $c_code = "int add(int a, int b);"; // Load the shared library (libadd.so must export 'add') $ffi = FFI::cdef($c_code, "libadd.so"); // Call the C function from PHP $result = $ffi->add(2, 3); echo "2 + 3 = " . $result . "\n";
A common mistake when using FFI::cdef() is failing to match the C declaration syntax exactly. For instance, forgetting a semicolon at the end of a declaration or specifying an incorrect type will cause PHP to throw a parse error. Always double-check your C declaration strings for proper syntax to avoid these issues.
Дякуємо за ваш відгук!
