Mohun Biswas' improvements and clarifications about the options and how to use

The pointers \fI*firstitem\fP and \fI*lastitem\fP should both be pointing to

NULL in the first call to this function. All list-data will be allocated by

the function itself. You must call \fIcurl_formfree\fP after the form post has

been done to free the resources again.

the function itself. You must call \fIcurl_formfree(3)\fP after the form post

has been done to free the resources.

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header.

You can disable this header with \fICURLOPT_HTTPHEADER\fP as usual.

First, there are some basics you need to understand about multipart/formdata

posts. Each part consists of at least a NAME and a CONTENTS part. If the part

is made for file upload, there are also a stored CONTENT-TYPE and a

FILENAME. Below here, we'll discuss on what options you use to set these

properties in the parts you want to add to your post.

is made for file upload, there are also a stored CONTENT-TYPE and a FILENAME.

Below, we'll discuss what options you use to set these properties in the

parts you want to add to your post.

The options listed first are for making normal parts. The options from

\fICURLFORM_FILE\fP through \fICURLFORM_BUFFERLENGTH\fP are for file upload

parts.

.SH OPTIONS

.IP CURLFORM_COPYNAME

followed by string is used to set the name of this part. libcurl copies the

given data, so your application doesn't need to keep it around after this

function call. If the name isn't zero terminated properly, or if you'd like it

to contain zero bytes, you need to set the length of the name with

\fBCURLFORM_NAMELENGTH\fP.

followed by a string which provides the \fIname\fP of this part. libcurl

copies the string so your application doesn't need to keep it around after

this function call. If the name isn't null terminated, or if you'd

like it to contain zero bytes, you must set its length with

\fBCURLFORM_NAMELENGTH\fP. The copied data will be freed by

\fIcurl_formfree(3)\fP.

.IP CURLFORM_PTRNAME

followed by a string is used for the name of this part. libcurl will use the

pointer and refer to the data in your application, you must make sure it

remains until curl no longer needs it. If the name isn't zero terminated

properly, or if you'd like it to contain zero bytes, you need to set the

length of the name with \fBCURLFORM_NAMELENGTH\fP.

followed by a string which provides the \fIname\fP of this part. libcurl

will use the pointer and refer to the data in your application, so you

must make sure it remains until curl no longer needs it. If the name

isn't null terminated, or if you'd like it to contain zero

bytes, you must set its length with \fBCURLFORM_NAMELENGTH\fP.

.IP CURLFORM_COPYCONTENTS

followed by a string is used for the contents of this part, the actual data to

send away. libcurl copies the given data, so your application doesn't need to

keep it around after this function call. If the data isn't zero terminated

properly, or if you'd like it to contain zero bytes, you need to set the

length of the name with \fBCURLFORM_CONTENTSLENGTH\fP.

followed by a pointer to the contents of this part, the actual data

to send away. libcurl copies the provided data, so your application doesn't

need to keep it around after this function call. If the data isn't null

terminated, or if you'd like it to contain zero bytes, you must

set the length of the name with \fBCURLFORM_CONTENTSLENGTH\fP. The copied

data will be freed by \fIcurl_formfree(3)\fP.

.IP CURLFORM_PTRCONTENTS

followed by a string is used for the contents of this part, the actual data to

send away. libcurl will use the pointer and refer to the data in your

application, you must make sure it remains until curl no longer needs it. If

the data isn't zero terminated properly, or if you'd like it to contain zero

bytes, you need to set the length of the name with

\fBCURLFORM_CONTENTSLENGTH\fP.

followed by a pointer to the contents of this part, the actual data

to send away. libcurl will use the pointer and refer to the data in your

application, so you must make sure it remains until curl no longer needs it.

If the data isn't null terminated, or if you'd like it to contain zero bytes,

you must set its length  with \fBCURLFORM_CONTENTSLENGTH\fP.

.IP CURLFORM_CONTENTSLENGTH

followed by a long setting the length of the contents.

followed by a long giving the length of the contents.

.IP CURLFORM_FILECONTENT

followed by a file name, makes that file read and the contents will be used in

as data in this part.

followed by a filename, causes that file to be read and its contents used

as data in this part. This part does \fInot\fP automatically become a file

upload part simply because its data was read from a file.

.IP CURLFORM_FILE

followed by a file name, makes this part a file upload part. It sets the file

name field to the actual file name used here, it gets the contents of the file

and passes as data and sets the content-type if the given file match one of

the new internally known file extension.  For \fBCURLFORM_FILE\fP the user may

send one or more files in one part by providing multiple \fBCURLFORM_FILE\fP

arguments each followed by the filename (and each CURLFORM_FILE is allowed to

have a CURLFORM_CONTENTTYPE).

followed by a filename, makes this part a file upload part. It sets the

\fIfilename\fP field to the basename of the provided filename, it reads the

contents of the file and passes them as data and sets the content-type if the

given file match one of the internally known file extensions.  For

\fBCURLFORM_FILE\fP the user may send one or more files in one part by

providing multiple \fBCURLFORM_FILE\fP arguments each followed by the

filename (and each CURLFORM_FILE is allowed to have a CURLFORM_CONTENTTYPE).

.IP CURLFORM_CONTENTTYPE

followed by a pointer to a string with a content-type will make curl use this

given content-type for this file upload part, possibly instead of an

is used in combination with \fICURLFORM_FILE\fP. Followed by a pointer to a

string which provides the content-type for this part, possibly instead of an

internally chosen one.

.IP CURLFORM_FILENAME

followed by a pointer to a string to a name, will make libcurl use the given

name in the file upload part, instead of the actual file name given to

\fICURLFORM_FILE\fP.

is used in combination with \fICURLFORM_FILE\fP. Followed by a pointer to a

string, it tells libcurl to use the given string as the \fIfilename\fP in the

file upload part instead of the actual file name.

.IP CURLFORM_BUFFER

followed by a string, tells libcurl that a buffer is to be used to upload data

instead of using a file. The given string is used as the value of the file

name field in the content header.

is used for custom file upload parts without use of \fICURLFORM_FILE\fP.  It

tells libcurl that the file contents are already present in a buffer.  The

parameter is a string which provides the \fIfilename\fP field in the content

header.

.IP CURLFORM_BUFFERPTR

followed by a pointer to a data area, tells libcurl the address of the buffer

containing data to upload (as indicated with \fICURLFORM_BUFFER\fP). The

buffer containing this data must not be freed until after

is used in combination with \fICURLFORM_BUFFER\fP. The parameter is a pointer

to the buffer to be uploaded. This buffer must not be freed until after

\fIcurl_easy_cleanup(3)\fP is called. You must also use

\fICURLFORM_BUFFERLENGTH\fP to set the length of the given buffer area.

\fICURLFORM_BUFFERLENGTH\fP to set the number of bytes in the buffer.

.IP CURLFORM_BUFFERLENGTH

followed by a long with the size of the \fICURLFORM_BUFFERPTR\fP data area,

tells libcurl the length of the buffer to upload.

is used in combination with \fICURLFORM_BUFFER\fP. The parameter is a

long which gives the length of the buffer.

.IP CURLFORM_ARRAY

Another possibility to send options to curl_formadd() is the