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 +1,110 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLOPT_ERRORBUFFER
+Section: 3
+Source: libcurl
+See-also:
+  - CURLOPT_DEBUGFUNCTION (3)
+  - CURLOPT_VERBOSE (3)
+  - curl_easy_strerror (3)
+  - curl_multi_strerror (3)
+  - curl_share_strerror (3)
+  - curl_url_strerror (3)
+Protocol:
+  - All
+Added-in: 7.1
+---
+
+# NAME
+
+CURLOPT_ERRORBUFFER - error buffer for error messages
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ERRORBUFFER, char *buf);
+~~~
+
+# DESCRIPTION
+
+Pass a char pointer to a buffer that libcurl may use to store human readable
+error messages on failures or problems. This may be more helpful than just the
+return code from curl_easy_perform(3) and related functions. The buffer must
+be at least **CURL_ERROR_SIZE** bytes big.
+
+You must keep the associated buffer available until libcurl no longer needs
+it. Failing to do so might cause odd behavior or even crashes. libcurl might
+need it until you call curl_easy_cleanup(3) or you set the same option again
+to use a different pointer.
+
+Do not rely on the contents of the buffer unless an error code was returned.
+Since 7.60.0 libcurl initializes the contents of the error buffer to an empty
+string before performing the transfer. For earlier versions if an error code
+was returned but there was no error detail then the buffer was untouched.
+
+Do not attempt to set the contents of the buffer yourself, including in any
+callbacks you write that may be called by libcurl. The library may overwrite
+the buffer after your callback returns.
+
+Consider CURLOPT_VERBOSE(3) and CURLOPT_DEBUGFUNCTION(3) to better debug and
+trace why errors happen.
+
+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
+#include <string.h> /* for strlen() */
+int main(void)
+{
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    CURLcode res;
+    char errbuf[CURL_ERROR_SIZE];
+
+    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
+
+    /* provide a buffer to store errors in */
+    curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errbuf);
+
+    /* set the error buffer as empty before performing a request */
+    errbuf[0] = 0;
+
+    /* perform the request */
+    res = curl_easy_perform(curl);
+
+    /* if the request did not complete correctly, show the error
+    information. if no detailed error information was written to errbuf
+    show the more generic information from curl_easy_strerror instead.
+    */
+    if(res != CURLE_OK) {
+      size_t len = strlen(errbuf);
+      fprintf(stderr, "\nlibcurl: (%d) ", res);
+      if(len)
+        fprintf(stderr, "%s%s", errbuf,
+                ((errbuf[len - 1] != '\n') ? "\n" : ""));
+      else
+        fprintf(stderr, "%s\n", curl_easy_strerror(res));
+    }
+  }
+}
+~~~
+
+# %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).