php_stream_is() returns 1 if stream is of the type specified by istype, or 0 otherwise.
Table 44-1. Values for istype
| Value | Meaning |
|---|---|
| PHP_STREAM_IS_STDIO | The stream is implemented using the stdio implementation |
| PHP_STREAM_IS_SOCKET | The stream is implemented using the network socket implementation |
| PHP_STREAM_IS_USERSPACE | The stream is implemented using the userspace object implementation |
| PHP_STREAM_IS_MEMORY | The stream is implemented using the grow-on-demand memory stream implementation |
Note: The PHP_STREAM_IS_XXX "constants" are actually defined as pointers to the underlying stream operations structure. If your extension (or some other extension) defines additional streams, it should also declare a PHP_STREAM_IS_XXX constant in it's header file that you can use as the basis of this comparison.
Note: This function is implemented as a simple (and fast) pointer comparison, and does not change the stream state in any way.
See also php_stream_cast() and php_stream_can_cast().