curl-w32/docs/libcurl/opts/CURLOPT_CONV_FROM_NETWORK_FUNCTION.md

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c SPDX-License-Identifier Title Section Source See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al. curl CURLOPT_CONV_FROM_NETWORK_FUNCTION 3 libcurl
CURLOPT_CONV_FROM_UTF8_FUNCTION (3)
CURLOPT_CONV_TO_NETWORK_FUNCTION (3)

NAME

CURLOPT_CONV_FROM_NETWORK_FUNCTION - convert data from network to host encoding

SYNOPSIS

#include <curl/curl.h>

CURLcode conv_callback(char *ptr, size_t length);

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

DESCRIPTION

Pass a pointer to your callback function, which should match the prototype shown above.

Applies to non-ASCII platforms. curl_version_info(3) returns the CURL_VERSION_CONV feature bit set if this option is provided.

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.

CURLOPT_CONV_FROM_NETWORK_FUNCTION(3) 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 do not set it at all, the built-in libcurl iconv functions are used. If HAVE_ICONV was not defined when libcurl was built, and no callback has been established, the conversion returns 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 defaults 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 need to override these definitions if they are different on your system.

DEFAULT

NULL

PROTOCOLS

FTP, SMTP, IMAP, POP3

EXAMPLE

static CURLcode my_conv_from_ascii_to_ebcdic(char *buffer, size_t length)
{
  int rc = 0;

  /* in-place convert 'buffer' from ASCII to EBCDIC */

  if(rc == 0) {
    /* success */
    return CURLE_OK;
  }
  else {
    return CURLE_CONV_FAILED;
  }
}

int main(void)
{
  CURL *curl = curl_easy_init();

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

AVAILABILITY

Not available and deprecated since 7.82.0.

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.