curl_easy_perform.3 2.6 KB

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  1. .\" generated by cd2nroff 0.1 from curl_easy_perform.md
  2. .TH curl_easy_perform 3 "2025-01-17" libcurl
  3. .SH NAME
  4. curl_easy_perform \- perform a blocking network transfer
  5. .SH SYNOPSIS
  6. .nf
  7. #include <curl/curl.h>
  8. CURLcode curl_easy_perform(CURL *easy_handle);
  9. .fi
  10. .SH DESCRIPTION
  11. \fIcurl_easy_perform(3)\fP performs a network transfer in a blocking manner and
  12. returns when done, or earlier if it fails. For non\-blocking behavior, see
  13. \fIcurl_multi_perform(3)\fP.
  14. Invoke this function after \fIcurl_easy_init(3)\fP and all the \fIcurl_easy_setopt(3)\fP
  15. calls are made, and it performs the transfer as described in the options. It
  16. must be called with the same \fBeasy_handle\fP as input as the \fIcurl_easy_init(3)\fP
  17. call returned.
  18. You can do any amount of calls to \fIcurl_easy_perform(3)\fP while using the same
  19. \fBeasy_handle\fP. If you intend to transfer more than one file, you are even
  20. encouraged to do so. libcurl attempts to reuse existing connections for the
  21. following transfers, thus making the operations faster, less CPU intense and
  22. using less network resources. You probably want to use \fIcurl_easy_setopt(3)\fP
  23. between the invokes to set options for the following \fIcurl_easy_perform(3)\fP
  24. call.
  25. You must never call this function simultaneously from two places using the
  26. same \fBeasy_handle\fP. Let the function return first before invoking it another
  27. time. If you want parallel transfers, you must use several curl easy_handles.
  28. A network transfer moves data to a peer or from a peer. An application tells
  29. libcurl how to receive data by setting the \fICURLOPT_WRITEFUNCTION(3)\fP and
  30. \fICURLOPT_WRITEDATA(3)\fP options. To tell libcurl what data to send, there are a
  31. few more alternatives but two common ones are \fICURLOPT_READFUNCTION(3)\fP and
  32. \fICURLOPT_POSTFIELDS(3)\fP.
  33. While the \fBeasy_handle\fP is added to a multi handle, it cannot be used by
  34. \fIcurl_easy_perform(3)\fP.
  35. .SH PROTOCOLS
  36. This functionality affects all supported protocols
  37. .SH EXAMPLE
  38. .nf
  39. int main(void)
  40. {
  41. CURL *curl = curl_easy_init();
  42. if(curl) {
  43. CURLcode res;
  44. curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
  45. res = curl_easy_perform(curl);
  46. curl_easy_cleanup(curl);
  47. }
  48. }
  49. .fi
  50. .SH AVAILABILITY
  51. Added in curl 7.1
  52. .SH RETURN VALUE
  53. CURLE_OK (0) means everything was OK, non\-zero means an error occurred as
  54. \fI<curl/curl.h>\fP defines \- see \fIlibcurl\-errors(3)\fP. If \fICURLOPT_ERRORBUFFER(3)\fP
  55. was set with \fIcurl_easy_setopt(3)\fP there is an error message stored in the error
  56. buffer when non\-zero is returned.
  57. .SH SEE ALSO
  58. .BR curl_easy_init (3),
  59. .BR curl_easy_setopt (3),
  60. .BR curl_multi_add_handle (3),
  61. .BR curl_multi_perform (3),
  62. .BR libcurl-errors (3)