Update networking layer w/ CURL and emscripten impl

2025-11-08 01:50:36 +11:00
parent a17925904d
commit f6874dc55a
4105 changed files with 694617 additions and 179 deletions
@@ -0,0 +1,130 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLOPT_POSTFIELDS
+Section: 3
+Source: libcurl
+See-also:
+  - CURLOPT_COPYPOSTFIELDS (3)
+  - CURLOPT_MIMEPOST (3)
+  - CURLOPT_POSTFIELDSIZE (3)
+  - CURLOPT_READFUNCTION (3)
+  - CURLOPT_UPLOAD (3)
+Protocol:
+  - HTTP
+  - MQTT
+Added-in: 7.1
+---
+
+# NAME
+
+CURLOPT_POSTFIELDS - data to POST to server
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_POSTFIELDS, char *postdata);
+~~~
+
+# DESCRIPTION
+
+Pass a char pointer as parameter, pointing to the data buffer to use in an
+HTTP POST operation or an MQTT subscribe. The data must be formatted and
+encoded the way you want the server to receive it. libcurl does not convert or
+encode it in any way. For example, a web server may assume that this data is
+URL encoded.
+
+The data pointed to is NOT copied by the library: as a consequence, it must be
+preserved by the calling application until the associated transfer finishes.
+This behavior can be changed (so libcurl does copy the data) by instead using
+the CURLOPT_COPYPOSTFIELDS(3) option.
+
+This POST is a normal **application/x-www-form-urlencoded** kind (and libcurl
+sets that Content-Type by default when this option is used), which is commonly
+used by HTML forms. Change Content-Type with CURLOPT_HTTPHEADER(3).
+
+You can use curl_easy_escape(3) to URL encode your data, if
+necessary. It returns a pointer to an encoded string that can be passed as
+*postdata*.
+
+Using CURLOPT_POSTFIELDS(3) implies setting CURLOPT_POST(3) to 1.
+
+If CURLOPT_POSTFIELDS(3) is explicitly set to NULL then libcurl gets the POST
+data from the read callback. To send a zero-length (empty) POST, set
+CURLOPT_POSTFIELDS(3) to an empty string, or set CURLOPT_POST(3) to 1 and
+CURLOPT_POSTFIELDSIZE(3) to 0.
+
+libcurl assumes this option points to a null-terminated string unless you also
+set CURLOPT_POSTFIELDSIZE(3) to specify the length of the provided data, which
+then is strictly required if you want to send off null bytes included in the
+data.
+
+Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header,
+and libcurl adds that header automatically if the POST is either known to be
+larger than 1MB or if the expected size is unknown. You can disable this
+header with CURLOPT_HTTPHEADER(3) as usual.
+
+To make **multipart/formdata** posts, check out the
+CURLOPT_MIMEPOST(3) option combined with curl_mime_init(3).
+
+Using this option multiple times makes the last set pointer override the
+previous ones. Set it to NULL to disable its use again.
+
+# DEFAULT
+
+NULL
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+/* send an application/x-www-form-urlencoded POST */
+int main(void)
+{
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    const char *data = "data to send";
+
+    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
+
+    /* size of the POST data if strlen() is not good enough */
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, 12L);
+
+    /* pass in a pointer to the data - libcurl does not copy */
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data);
+
+    curl_easy_perform(curl);
+  }
+
+  /* send an application/json POST */
+  curl = curl_easy_init();
+  if(curl) {
+    const char *json = "{\"name\": \"daniel\"}";
+    struct curl_slist *slist1 = NULL;
+    slist1 = curl_slist_append(slist1, "Content-Type: application/json");
+    slist1 = curl_slist_append(slist1, "Accept: application/json");
+
+    /* set custom headers */
+    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, slist1);
+
+    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
+
+    /* pass in a pointer to the data - libcurl does not copy */
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, json);
+
+    curl_easy_perform(curl);
+  }
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+curl_easy_setopt(3) returns a CURLcode indicating success or error.
+
+CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
+libcurl-errors(3).