romenskiy2012/curl

mirror of https://github.com/curl/curl.git synced 2026-04-24 23:52:13 +03:00

Daniel Stenberg 54ded66618

docs/libcurl: improve easy setopt examples

- always assign the curl_easy_perform() return code (and declare
  the necessary 'result' variable for it)

- always call curl_easy_cleanup() on the created easy handles

Closes #21364

2026-04-18 23:34:39 +02:00

1.6 KiB

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SPDX-License-Identifier

Title

Section

Source

See-also

Protocol

Added-in

curl

CURLOPT_PROGRESSDATA

libcurl

CURLOPT_PROGRESSFUNCTION (3)

CURLOPT_XFERINFOFUNCTION (3)

All

7.1

NAME

CURLOPT_PROGRESSDATA - pointer passed to the progress callback

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROGRESSDATA, void *pointer);

DESCRIPTION

Pass a pointer that is untouched by libcurl and passed as the first argument in the progress callback set with CURLOPT_PROGRESSFUNCTION(3).

DEFAULT

NULL

%PROTOCOLS%

EXAMPLE

struct progress {
  char *private;
  size_t size;
};

static int progress_callback(void *clientp,
                             double dltotal,
                             double dlnow,
                             double ultotal,
                             double ulnow)
{
  struct progress *memory = clientp;
  printf("private: %p\n", memory->private);

  /* use the values */

  return 0; /* all is good */
}

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    struct progress data;

    /* pass struct to callback */
    curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, &data);
    curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progress_callback);

    result = curl_easy_perform(curl);
    curl_easy_cleanup(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).

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