CURLcode

CURLcode is an enumeration type used by the libcurl library to represent the result of a transfer operation. Each member of the CURLcode enum signifies a specific outcome, ranging from successful completion to various error conditions. This allows applications using libcurl to easily check the status of their network requests and handle errors appropriately.

The most common success code is CURLE_OK, indicating that the transfer completed without any issues. Conversely, a wide array of error codes exists to pinpoint the exact cause of failure. These errors can be broadly categorized. For instance, CURLE_COULDNT_RESOLVE_HOST signifies a problem with DNS resolution, while CURLE_CONNECT_ERROR points to an issue establishing a connection to the server. Other categories include errors related to transferring data (e.g., CURLE_PARTIAL_FILE), SSL/TLS problems (e.g., CURLE_SSL_CACERT), and internal libcurl errors (e.g., CURLE_OUT_OF_MEMORY).

Developers typically check the return value of libcurl functions, such as curl_easy_perform, against the CURLcode enum. If the returned code is not CURLE_OK, the application can then consult documentation or use functions like curl_easy_strerror to obtain a human-readable string describing the specific error. This systematic approach to error handling is crucial for building robust network-aware applications.