Espressif ESP32-S2 User Manual

Chapter 2. API Reference
esp_err_t httpd_resp_set_hdr(httpd_req_t *r, const char *field, const char *value)
API to append any additional headers.
This API sets any additional header fields that need to be sent in the response.
Note
• This API is supposed to be called only from the context of a URI handler where httpd_req_t* request
pointer is valid.
• The header isn’t sent out until any of the send APIs is executed.
• The maximum allowed number of additional headers is limited to value of max_resp_headers in
config structure.
• Make sure that the lifetime of the field value strings are valid till send function is called.
Return
• ESP_OK : On successfully appending new header
• ESP_ERR_INVALID_ARG : Null arguments
• ESP_ERR_HTTPD_RESP_HDR : Total additional headers exceed max allowed
• ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
Parameters
• [in] r: The request being responded to
• [in] field: The field name of the HTTP header
• [in] value: The value of this HTTP header
esp_err_t httpd_resp_send_err(httpd_req_t *req, httpd_err_code_t error, const char *msg)
For sending out error code in response to HTTP request.
Note
• This API is supposed to be called only from the context of a URI handler where httpd_req_t* request
pointer is valid.
• Once this API is called, all request headers are purged, so request headers need be copied into
separate buffers if they are required later.
• If you wish to send additional data in the body of the response, please use the lower-level functions
directly.
Return
• ESP_OK : On successfully sending the response packet
• ESP_ERR_INVALID_ARG : Null arguments
• ESP_ERR_HTTPD_RESP_SEND : Error in raw send
• ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
Parameters
• [in] req: Pointer to the HTTP request for which the response needs to be sent
• [in] error: Error type to send
• [in] msg: Error message string (pass NULL for default message)
static esp_err_t httpd_resp_send_404(httpd_req_t *r)
Helper function for HTTP 404.
Send HTTP 404 message. If you wish to send additional data in the body of the response, please use the
lower-level functions directly.
Note
• This API is supposed to be called only from the context of a URI handler where httpd_req_t* request
pointer is valid.
• Once this API is called, all request headers are purged, so request headers need be copied into
separate buffers if they are required later.
Return
• ESP_OK : On successfully sending the response packet
• ESP_ERR_INVALID_ARG : Null arguments
• ESP_ERR_HTTPD_RESP_SEND : Error in raw send
• ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
Parameters
• [in] r: The request being responded to
static esp_err_t httpd_resp_send_408(httpd_req_t *r)
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Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English