curl_easy_send.3 3.4 KB

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  23. .TH curl_easy_send 3 "29 April 2008" "libcurl 7.18.2" "libcurl Manual"
  24. .SH NAME
  25. curl_easy_send - sends raw data over an "easy" connection
  26. .SH SYNOPSIS
  27. .B #include <curl/easy.h>
  28. .sp
  29. .BI "CURLcode curl_easy_send( CURL *" curl ", const void *" buffer ","
  30. .BI " size_t " buflen ", size_t *" n ");"
  31. .ad
  32. .SH DESCRIPTION
  33. This function sends arbitrary data over the established connection. You may
  34. use it together with \fIcurl_easy_recv(3)\fP to implement custom protocols
  35. using libcurl. This functionality can be particularly useful if you use
  36. proxies and/or SSL encryption: libcurl will take care of proxy negotiation and
  37. connection set-up.
  38. \fBbuffer\fP is a pointer to the data of length \fBbuflen\fP that you want sent.
  39. The variable \fBn\fP points to will receive the number of sent bytes.
  40. To establish the connection, set \fICURLOPT_CONNECT_ONLY(3)\fP option before
  41. calling \fIcurl_easy_perform(3)\fP or \fIcurl_multi_perform(3)\fP. Note that
  42. \fIcurl_easy_send(3)\fP will not work on connections that were created without
  43. this option.
  44. The call will return \fBCURLE_AGAIN\fP if it's not possible to send data right
  45. now - the socket is used in non-blocking mode internally. When
  46. \fBCURLE_AGAIN\fP is returned, use your operating system facilities like
  47. \fIselect(2)\fP to wait until the socket is writable. The socket may be
  48. obtained using \fIcurl_easy_getinfo(3)\fP with \fICURLINFO_ACTIVESOCKET(3)\fP.
  49. Furthermore if you wait on the socket and it tells you it's writable,
  50. \fIcurl_easy_send(3)\fP may return \fBCURLE_AGAIN\fP if the only data that was
  51. sent was for internal SSL processing, and no other data could be sent.
  52. .SH AVAILABILITY
  53. Added in 7.18.2.
  54. .SH RETURN VALUE
  55. On success, returns \fBCURLE_OK\fP and stores the number of bytes actually
  56. sent into \fB*n\fP. Note that this may very well be less than the amount you
  57. wanted to send.
  58. On failure, returns the appropriate error code.
  59. This function may return \fBCURLE_AGAIN\fP. In this case, use your operating
  60. system facilities to wait until the socket is writable, and retry.
  61. If there's no socket available to use from the previous transfer, this function
  62. returns \fBCURLE_UNSUPPORTED_PROTOCOL\fP.
  63. .SH EXAMPLE
  64. See \fBsendrecv.c\fP in \fBdocs/examples\fP directory for usage example.
  65. .SH "SEE ALSO"
  66. .BR curl_easy_setopt "(3), " curl_easy_perform "(3), " curl_easy_getinfo "(3), "
  67. .BR curl_easy_recv "(3) "