PR_Read 编辑

Reads bytes from a file or socket.

Syntax

#include <prio.h>

/wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRInt32 PR_Read(/wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRFileDesc *fd,
               void *buf,
               /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRInt32 amount);

Parameters

The function has the following parameters:

fd

A pointer to a /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRFileDesc object for the file or socket.

buf

A pointer to a buffer to hold the data read in. On output, the buffer contains the data.

amount

The size of buf (in bytes).

Returns

One of the following values:

• A positive number indicates the number of bytes actually read in.
• The value 0 means end of file is reached or the network connection is closed.
• The value -1 indicates a failure. To get the reason for the failure, call /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_GetError.

Description

The thread invoking PR_Read blocks until it encounters an end-of-stream indication, some positive number of bytes (but no more than amount bytes) are read in, or an error occurs.