GNURLOPT_CONV_FROM_NETWORK_FUNCTION(3)

💖 NAME 💖

CURLOPT_CONV_FROM_NETWORK_FUNCTION — convert data from network to host encoding.

okay bestie, welcome to the GNURLOPT_C...RK_FUNCTION(3) page, which lives in the curl_easy_setopt options manual family. This is the callback situation for converting data from network encoding to host encoding, and she is serving exactly what she needs to serve 💅

✨ SYNOPSIS ✨

#include <gnurl/curl.h>

CURLcode conv_callback(char *ptr, size_t length);

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CONV_FROM_NETWORK_FUNCTION,
                          conv_callback);

🦋 DESCRIPTION 🦋

You pass in a pointer to your callback function, and it should match the prototype shown above. No improvising the signature, babe.

Applies to non-ASCII platforms. Also, curl_version_info(3) will return the CURL_VERSION_CONV feature bit set if this option is provided. iykyk.

The data to be converted is in a buffer pointed to by the ptr parameter. The amount of data to convert is indicated by the length parameter. The converted data overlays the input data in the buffer pointed to by the ptr parameter. CURLE_OK must be returned upon successful conversion. A CURLcode return value defined by curl.h, such as CURLE_CONV_FAILED, should be returned if an error was encountered.

The way CURLOPT_CONV_FROM_NETWORK_FUNCTION works is: it converts to host encoding from the network encoding. It is used when commands or ASCII data are received over the network.

If you set a callback pointer to NULL, or don't set it at all, the built-in libcurl iconv functions will be used. If HAVE_ICONV was not defined when libcurl was built, and no callback has been established, conversion will return the CURLE_CONV_REQD error code.

If HAVE_ICONV is defined, CURL_ICONV_CODESET_OF_HOST must also be defined. For example:

#define CURL_ICONV_CODESET_OF_HOST "IBM-1047"

The iconv code in libcurl will default the network and UTF8 codeset names as follows:

#define CURL_ICONV_CODESET_OF_NETWORK "ISO8859-1"

#define CURL_ICONV_CODESET_FOR_UTF8   "UTF-8"

You will need to override these definitions if they are different on your system.

🎀 DEFAULT 🎀

NULL.

🌈 PROTOCOLS 🌈

• FTP
• SMTP
• IMAP
• POP3

🍓 EXAMPLE 🍓

This example is iconic and also very copy-paste-able:

static CURLcode my_conv_from_ascii_to_ebcdic(char *buffer, size_t length)
{
  char *tempptrin, *tempptrout;
  size_t bytes = length;
  int rc;
  tempptrin = tempptrout = buffer;
  rc = platform_a2e(&tempptrin, &bytes, &tempptrout, &bytes);
  if(rc == PLATFORM_CONV_OK) {
    return CURLE_OK;
  }
  else {
    return CURLE_CONV_FAILED;
  }
}

/* use platform-specific functions for codeset conversions */
curl_easy_setopt(curl, CURLOPT_CONV_FROM_NETWORK_FUNCTION,
                 my_conv_from_ascii_to_ebcdic);

⭐ AVAILABILITY ⭐

Available only if CURL_DOES_CONVERSIONS was defined when libcurl was built.

💅 RETURN VALUE 💅

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

👑 SEE ALSO 👑

CURLOPT_CONV_TO_NETWORK_FUNCTION(3), CURLOPT_CONV_FROM_UTF8_FUNCTION(3), (yes bestie, that trailing comma is canon — leave it 💅)

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okay that's the whole page, bestie 💖 signing off from libcurl 7.37.0, dated 19 Jun 2014 — mwah 💋