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.TH curl_easy_setopt 3 "22 May 2000" "Curl 7.0" "libcurl Manual"
.SH NAME
curl_easy_setopt - Set curl easy-session options
.SH SYNOPSIS
.B #include <curl/easy.h>
.sp
.BI "CURLcode curl_easy_setopt(CURL *" handle ", CURLoption "option ", ...);
.ad
.SH DESCRIPTION
curl_easy_setopt() is called to tell libcurl how to behave in a number of
ways. Most operations in libcurl have default actions, and by using the
appropriate options you can make them behave differently (as documented).  All
options are set with the
.I option
followed by a parameter. That parameter can be a long, a function pointer or
an object pointer, all depending on what the option in question expects. Read
this manual carefully as bad input values may cause libcurl to behave badly!

The
.I "handle"
is the return code from the
.I "curl_easy_init"
call.
.SH OPTIONS
.TP 0.8i
.B CURLOPT_FILE
Data pointer to pass instead of FILE * to the file write function. Note that
if you specify the
.I CURLOPT_WRITEFUNCTION
, this is the pointer you'll get as input.
.TP
.B CURLOPT_WRITEFUNCTION
Function pointer that should use match the following prototype:
.BI "size_t function( void *ptr, size_t size, size_t nmemb, FILE *stream);"
This function gets called by libcurl as soon as there is received data that
needs to be written down. The size of the data pointed to by
.I ptr 
is
.I size
multiplied with
.I nmemb.
Return the number of bytes actually written or return -1 to signal error to the library (it will cause it to abort the transfer).
.TP
.B CURLOPT_INFILE
Data pointer to pass instead of FILE * to the file read function. Note that if
you specify the
.I CURLOPT_READFUNCTION
, this is the pointer you'll get as input.
.TP
.B CURLOPT_READFUNCTION
Function pointer that should use match the following prototype:
.BI "size_t function( void *ptr, size_t size, size_t nmemb, FILE *stream);"
This function gets called by libcurl as soon as it needs to read data in order
to send it to the peer. The data area pointed at by the pointer
.I ptr
may be filled with at most
.I size
multiplied with
.I nmemb
number of bytes. Your function must return the actual number of bytes that you
stored in that memory area. Returning -1 will signal an error to the library
and cause it to abort the current transfer immediately.
.PP
.SH RETURN VALUE
0 means the option was set properly, non-zero means an error as
.I <curl/curl.h>
defines
.SH "SEE ALSO"
.BR curl_easy_init "(3), " curl_easy_cleanup "(3), "
.SH BUGS
Surely there are some, you tell me!