CURLOPT_RESUME_FROM

Section: C Library Functions (3)
Updated: 202-1-15
Index Return to Main Contents

---

 

NAME

CURLOPT_RESUME_FROM - offset to resume transfer from  

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESUME_FROM, long from);

 

DESCRIPTION

Pass a long as parameter. It contains the offset in number of bytes that you want the transfer to start from. Set this option to 0 to make the transfer start from the beginning (effectively disabling resume). For FTP, set this option to -1 to make the transfer start from the end of the target file (useful to continue an interrupted upload).

When doing uploads with FTP, the resume position is where in the local/source file libcurl should try to resume the upload from and it then appends the source file to the remote target file.

HTTP uploads using POST or PUT cannot be resumed. curl_easy_perform(3) returns CURLE_BAD_FUNCTION_ARGUMENT when this option is set to a non-zero value for such an upload.

If you need to resume a transfer beyond the 2GB limit, use CURLOPT_RESUME_FROM_LARGE(3) instead.  

DEFAULT

0, not used  

PROTOCOLS

This functionality affects all supported protocols  

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    long size_of_file = 6789;

    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com");

    /* resume upload at byte index 200 */
    curl_easy_setopt(curl, CURLOPT_RESUME_FROM, 200L);

    /* ask for upload */
    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

    /* set total data amount to expect */
    curl_easy_setopt(curl, CURLOPT_INFILESIZE, size_of_file);

    /* Perform the request */
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

 

AVAILABILITY

Added in curl 7.1  

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).  

SEE ALSO

CURLOPT_INFILESIZE(3), CURLOPT_RANGE(3), CURLOPT_RESUME_FROM_LARGE(3)

---

 

Index

NAME

SYNOPSIS

DESCRIPTION

DEFAULT

PROTOCOLS

EXAMPLE

AVAILABILITY

RETURN VALUE

SEE ALSO