PRFileDesc 编辑

A file descriptor used to represent any open file, such as a normal file, an end point of a pipe, or a socket (end point of network communication).

Syntax

#include <prio.h>

struct PRFileDesc {
  /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRIOMethods *methods;
  /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRFilePrivate *secret;
  PRFileDesc *lower, *higher;
  void (*dtor)(PRFileDesc *fd);
  /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRDescIdentity identity;
};

typedef struct PRFileDesc PRFileDesc;

Parameters

methods

The I/O methods table. See /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRIOMethods.

secret

Layer-dependent implementation data. See /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRFilePrivate.

lower

Pointer to lower layer.

higher

Pointer to higher layer.

dtor

A destructor function for the layer.

identity

Identity of this particular layer. See /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRDescIdentity.

Description

The fields of this structure are significant only if you are implementing a layer on top of NSPR, such as SSL. Otherwise, you use functions such as /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_Open and /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_NewTCPSocket to obtain a file descriptor, which you should treat as an opaque structure.

For more details about the use of PRFileDesc and related structures, see File Descriptor Types.