curlopt_WRITEFUNCTION
时间: 2023-09-02 17:07:15 浏览: 40
CURLOPT_WRITEFUNCTION is a callback function that is used to write the data received from a cURL request. When a cURL request is made, the data received from the server is passed to the callback function specified by CURLOPT_WRITEFUNCTION. The callback function can then process the data in any way it wants, such as writing it to a file or displaying it on the screen.
The syntax for setting CURLOPT_WRITEFUNCTION is as follows:
```
curl_easy_setopt(CURL *handle, CURLOPT_WRITEFUNCTION, write_callback_function);
```
The write_callback_function should have the following signature:
```
size_t write_callback_function(char *ptr, size_t size, size_t nmemb, void *userdata);
```
The parameters of the write_callback_function are:
- ptr: A pointer to the data received from the server
- size: The size of each element of the data (usually 1)
- nmemb: The number of elements in the data
- userdata: A pointer to user-defined data that can be passed to the callback function
The write_callback_function should return the number of bytes processed. If the function returns a value less than the total size of the data, cURL will assume that there was an error and the transfer will be aborted.