314 lines
12 KiB
Markdown
314 lines
12 KiB
Markdown
|
---
|
||
|
|
c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
|
||
|
|
SPDX-License-Identifier: curl
|
||
|
|
Title: curl_formadd
|
||
|
|
Section: 3
|
||
|
|
Source: libcurl
|
||
|
|
See-also:
|
||
|
|
- curl_easy_setopt (3)
|
||
|
|
- curl_formfree (3)
|
||
|
|
- curl_mime_init (3)
|
||
|
|
---
|
||
|
|
|
||
|
|
# NAME
|
||
|
|
|
||
|
|
curl_formadd - add a section to a multipart form POST
|
||
|
|
|
||
|
|
# SYNOPSIS
|
||
|
|
|
||
|
|
~~~c
|
||
|
|
#include <curl/curl.h>
|
||
|
|
|
||
|
|
CURLFORMcode curl_formadd(struct curl_httppost **firstitem,
|
||
|
|
struct curl_httppost **lastitem, ...);
|
||
|
|
~~~
|
||
|
|
|
||
|
|
# DESCRIPTION
|
||
|
|
|
||
|
|
**This function is deprecated.** Use curl_mime_init(3) instead.
|
||
|
|
|
||
|
|
curl_formadd() is used to append sections when building a multipart form
|
||
|
|
post. Append one section at a time until you have added all the sections you
|
||
|
|
want included and then you pass the *firstitem* pointer as parameter to
|
||
|
|
CURLOPT_HTTPPOST(3). *lastitem* is set after each curl_formadd(3) call and
|
||
|
|
on repeated invokes it should be left as set to allow repeated invokes to find
|
||
|
|
the end of the list faster.
|
||
|
|
|
||
|
|
After the *lastitem* pointer follow the real arguments.
|
||
|
|
|
||
|
|
The pointers *firstitem* and *lastitem* should both be pointing to
|
||
|
|
NULL in the first call to this function. All list-data is allocated by the
|
||
|
|
function itself. You must call curl_formfree(3) on the *firstitem*
|
||
|
|
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 CURLOPT_HTTPHEADER(3) as usual.
|
||
|
|
|
||
|
|
First, there are some basics you need to understand about multipart form
|
||
|
|
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, we 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
|
||
|
|
*CURLFORM_FILE* through *CURLFORM_BUFFERLENGTH* are for file upload
|
||
|
|
parts.
|
||
|
|
|
||
|
|
# OPTIONS
|
||
|
|
|
||
|
|
## CURLFORM_COPYNAME
|
||
|
|
|
||
|
|
followed by a string which provides the *name* of this part. libcurl
|
||
|
|
copies the string so your application does not need to keep it around after
|
||
|
|
this function call. If the name is not null-terminated, you must set its
|
||
|
|
length with **CURLFORM_NAMELENGTH**. The *name* is not allowed to
|
||
|
|
contain zero-valued bytes. The copied data is freed by curl_formfree(3).
|
||
|
|
|
||
|
|
## CURLFORM_PTRNAME
|
||
|
|
|
||
|
|
followed by a string which provides the *name* of this part. libcurl uses 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 is not null-terminated, you
|
||
|
|
must set its length with **CURLFORM_NAMELENGTH**. The *name* is not allowed to
|
||
|
|
contain zero-valued bytes.
|
||
|
|
|
||
|
|
## CURLFORM_COPYCONTENTS
|
||
|
|
|
||
|
|
followed by a pointer to the contents of this part, the actual data to send
|
||
|
|
away. libcurl copies the provided data, so your application does not need to
|
||
|
|
keep it around after this function call. If the data is not null terminated,
|
||
|
|
or if you would like it to contain zero bytes, you must set the length of the
|
||
|
|
name with **CURLFORM_CONTENTSLENGTH**. The copied data is freed by
|
||
|
|
curl_formfree(3).
|
||
|
|
|
||
|
|
## CURLFORM_PTRCONTENTS
|
||
|
|
|
||
|
|
followed by a pointer to the contents of this part, the actual data to send
|
||
|
|
away. libcurl uses 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 is
|
||
|
|
not null-terminated, or if you would like it to contain zero bytes, you must
|
||
|
|
set its length with **CURLFORM_CONTENTSLENGTH**.
|
||
|
|
|
||
|
|
## CURLFORM_CONTENTLEN
|
||
|
|
|
||
|
|
followed by a curl_off_t value giving the length of the contents. Note that
|
||
|
|
for *CURLFORM_STREAM* contents, this option is mandatory.
|
||
|
|
|
||
|
|
If you pass a 0 (zero) for this option, libcurl calls strlen() on the contents
|
||
|
|
to figure out the size. If you really want to send a zero byte content then
|
||
|
|
you must make sure strlen() on the data pointer returns zero.
|
||
|
|
|
||
|
|
(Option added in 7.46.0)
|
||
|
|
|
||
|
|
## CURLFORM_CONTENTSLENGTH
|
||
|
|
|
||
|
|
(This option is deprecated. Use *CURLFORM_CONTENTLEN* instead!)
|
||
|
|
|
||
|
|
followed by a long giving the length of the contents. Note that for
|
||
|
|
*CURLFORM_STREAM* contents, this option is mandatory.
|
||
|
|
|
||
|
|
If you pass a 0 (zero) for this option, libcurl calls strlen() on the contents
|
||
|
|
to figure out the size. If you really want to send a zero byte content then
|
||
|
|
you must make sure strlen() on the data pointer returns zero.
|
||
|
|
|
||
|
|
## CURLFORM_FILECONTENT
|
||
|
|
|
||
|
|
followed by a filename, causes that file to be read and its contents used
|
||
|
|
as data in this part. This part does *not* automatically become a file
|
||
|
|
upload part simply because its data was read from a file.
|
||
|
|
|
||
|
|
The specified file needs to kept around until the associated transfer is done.
|
||
|
|
|
||
|
|
## CURLFORM_FILE
|
||
|
|
|
||
|
|
followed by a filename, makes this part a file upload part. It sets the
|
||
|
|
*filename* 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
|
||
|
|
**CURLFORM_FILE** the user may send one or more files in one part by
|
||
|
|
providing multiple **CURLFORM_FILE** arguments each followed by the filename
|
||
|
|
(and each *CURLFORM_FILE* is allowed to have a
|
||
|
|
*CURLFORM_CONTENTTYPE*).
|
||
|
|
|
||
|
|
The given upload file has to exist in its full in the file system already when
|
||
|
|
the upload starts, as libcurl needs to read the correct file size beforehand.
|
||
|
|
|
||
|
|
The specified file needs to kept around until the associated transfer is done.
|
||
|
|
|
||
|
|
## CURLFORM_CONTENTTYPE
|
||
|
|
|
||
|
|
is used in combination with *CURLFORM_FILE*. Followed by a pointer to a
|
||
|
|
string which provides the content-type for this part, possibly instead of an
|
||
|
|
internally chosen one.
|
||
|
|
|
||
|
|
## CURLFORM_FILENAME
|
||
|
|
|
||
|
|
is used in combination with *CURLFORM_FILE*. Followed by a pointer to a
|
||
|
|
string, it tells libcurl to use the given string as the *filename* in the file
|
||
|
|
upload part instead of the actual filename.
|
||
|
|
|
||
|
|
## CURLFORM_BUFFER
|
||
|
|
|
||
|
|
is used for custom file upload parts without use of *CURLFORM_FILE*. It
|
||
|
|
tells libcurl that the file contents are already present in a buffer. The
|
||
|
|
parameter is a string which provides the *filename* field in the content
|
||
|
|
header.
|
||
|
|
|
||
|
|
## CURLFORM_BUFFERPTR
|
||
|
|
|
||
|
|
is used in combination with *CURLFORM_BUFFER*. The parameter is a pointer
|
||
|
|
to the buffer to be uploaded. This buffer must not be freed until after
|
||
|
|
curl_easy_cleanup(3) is called. You must also use
|
||
|
|
*CURLFORM_BUFFERLENGTH* to set the number of bytes in the buffer.
|
||
|
|
|
||
|
|
## CURLFORM_BUFFERLENGTH
|
||
|
|
|
||
|
|
is used in combination with *CURLFORM_BUFFER*. The parameter is a
|
||
|
|
long which gives the length of the buffer.
|
||
|
|
|
||
|
|
## CURLFORM_STREAM
|
||
|
|
|
||
|
|
Tells libcurl to use the CURLOPT_READFUNCTION(3) callback to get
|
||
|
|
data. The parameter you pass to *CURLFORM_STREAM* is the pointer passed on
|
||
|
|
to the read callback's fourth argument. If you want the part to look like a
|
||
|
|
file upload one, set the *CURLFORM_FILENAME* parameter as well. Note that
|
||
|
|
when using *CURLFORM_STREAM*, *CURLFORM_CONTENTSLENGTH* must also be
|
||
|
|
set with the total expected length of the part unless the formpost is sent
|
||
|
|
chunked encoded. (Option added in libcurl 7.18.2)
|
||
|
|
|
||
|
|
## CURLFORM_ARRAY
|
||
|
|
|
||
|
|
Another possibility to send options to curl_formadd() is the
|
||
|
|
**CURLFORM_ARRAY** option, that passes a struct curl_forms array pointer as
|
||
|
|
its value. Each curl_forms structure element has a *CURLformoption* and a
|
||
|
|
char pointer. The final element in the array must be a CURLFORM_END. All
|
||
|
|
available options can be used in an array, except the CURLFORM_ARRAY option
|
||
|
|
itself. The last argument in such an array must always be **CURLFORM_END**.
|
||
|
|
|
||
|
|
## CURLFORM_CONTENTHEADER
|
||
|
|
|
||
|
|
specifies extra headers for the form POST section. This takes a curl_slist
|
||
|
|
prepared in the usual way using **curl_slist_append** and appends the list
|
||
|
|
of headers to those libcurl automatically generates. The list must exist while
|
||
|
|
the POST occurs, if you free it before the post completes you may experience
|
||
|
|
problems.
|
||
|
|
|
||
|
|
When you have passed the *struct curl_httppost* pointer to
|
||
|
|
curl_easy_setopt(3) (using the CURLOPT_HTTPPOST(3) option), you
|
||
|
|
must not free the list until after you have called curl_easy_cleanup(3)
|
||
|
|
for the curl handle.
|
||
|
|
|
||
|
|
See example below.
|
||
|
|
|
||
|
|
# EXAMPLE
|
||
|
|
|
||
|
|
~~~c
|
||
|
|
#include <string.h> /* for strlen */
|
||
|
|
|
||
|
|
static const char record[]="data in a buffer";
|
||
|
|
|
||
|
|
int main(void)
|
||
|
|
{
|
||
|
|
CURL *curl = curl_easy_init();
|
||
|
|
if(curl) {
|
||
|
|
struct curl_httppost *post = NULL;
|
||
|
|
struct curl_httppost *last = NULL;
|
||
|
|
char namebuffer[] = "name buffer";
|
||
|
|
long namelength = strlen(namebuffer);
|
||
|
|
char buffer[] = "test buffer";
|
||
|
|
char htmlbuffer[] = "<HTML>test buffer</HTML>";
|
||
|
|
long htmlbufferlength = strlen(htmlbuffer);
|
||
|
|
struct curl_forms forms[3];
|
||
|
|
char file1[] = "my-face.jpg";
|
||
|
|
char file2[] = "your-face.jpg";
|
||
|
|
/* add null character into htmlbuffer, to demonstrate that
|
||
|
|
transfers of buffers containing null characters actually work
|
||
|
|
*/
|
||
|
|
htmlbuffer[8] = '\0';
|
||
|
|
|
||
|
|
/* Add simple name/content section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "name",
|
||
|
|
CURLFORM_COPYCONTENTS, "content", CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add simple name/content/contenttype section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "htmlcode",
|
||
|
|
CURLFORM_COPYCONTENTS, "<HTML></HTML>",
|
||
|
|
CURLFORM_CONTENTTYPE, "text/html", CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add name/ptrcontent section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "name_for_ptrcontent",
|
||
|
|
CURLFORM_PTRCONTENTS, buffer, CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add ptrname/ptrcontent section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_PTRNAME, namebuffer,
|
||
|
|
CURLFORM_PTRCONTENTS, buffer, CURLFORM_NAMELENGTH,
|
||
|
|
namelength, CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add name/ptrcontent/contenttype section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "html_code_with_hole",
|
||
|
|
CURLFORM_PTRCONTENTS, htmlbuffer,
|
||
|
|
CURLFORM_CONTENTSLENGTH, htmlbufferlength,
|
||
|
|
CURLFORM_CONTENTTYPE, "text/html", CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add simple file section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "picture",
|
||
|
|
CURLFORM_FILE, "my-face.jpg", CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add file/contenttype section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "picture",
|
||
|
|
CURLFORM_FILE, "my-face.jpg",
|
||
|
|
CURLFORM_CONTENTTYPE, "image/jpeg", CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add two file section */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "pictures",
|
||
|
|
CURLFORM_FILE, "my-face.jpg",
|
||
|
|
CURLFORM_FILE, "your-face.jpg", CURLFORM_END);
|
||
|
|
|
||
|
|
/* Add two file section using CURLFORM_ARRAY */
|
||
|
|
forms[0].option = CURLFORM_FILE;
|
||
|
|
forms[0].value = file1;
|
||
|
|
forms[1].option = CURLFORM_FILE;
|
||
|
|
forms[1].value = file2;
|
||
|
|
forms[2].option = CURLFORM_END;
|
||
|
|
|
||
|
|
/* Add a buffer to upload */
|
||
|
|
curl_formadd(&post, &last,
|
||
|
|
CURLFORM_COPYNAME, "name",
|
||
|
|
CURLFORM_BUFFER, "data",
|
||
|
|
CURLFORM_BUFFERPTR, record,
|
||
|
|
CURLFORM_BUFFERLENGTH, sizeof(record),
|
||
|
|
CURLFORM_END);
|
||
|
|
|
||
|
|
/* no option needed for the end marker */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "pictures",
|
||
|
|
CURLFORM_ARRAY, forms, CURLFORM_END);
|
||
|
|
/* Add the content of a file as a normal post text value */
|
||
|
|
curl_formadd(&post, &last, CURLFORM_COPYNAME, "filecontent",
|
||
|
|
CURLFORM_FILECONTENT, ".bashrc", CURLFORM_END);
|
||
|
|
/* Set the form info */
|
||
|
|
curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
|
||
|
|
|
||
|
|
curl_easy_perform(curl);
|
||
|
|
|
||
|
|
curl_easy_cleanup(curl);
|
||
|
|
|
||
|
|
curl_formfree(post);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
~~~
|
||
|
|
|
||
|
|
# AVAILABILITY
|
||
|
|
|
||
|
|
Deprecated in 7.56.0. Before this release, field names were allowed to
|
||
|
|
contain zero-valued bytes. The pseudo-filename "-" to read stdin is
|
||
|
|
discouraged although still supported, but data is not read before being
|
||
|
|
actually sent: the effective data size can then not be automatically
|
||
|
|
determined, resulting in a chunked encoding transfer. Backslashes and
|
||
|
|
double quotes in field and file names are now escaped before transmission.
|
||
|
|
|
||
|
|
# RETURN VALUE
|
||
|
|
|
||
|
|
0 means everything was OK, non-zero means an error occurred corresponding
|
||
|
|
to a CURL_FORMADD_* constant defined in
|
||
|
|
*<curl/curl.h>*
|