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curl_formadd(3)                                libcurl Manual                                curl_formadd(3)



NAME
       curl_formadd - add a section to a multipart/formdata HTTP POST

SYNOPSIS
       #include <curl/curl.h>

       CURLFORMcode curl_formadd(struct curl_httppost ** firstitem, struct curl_httppost ** lastitem, ...);

DESCRIPTION
       curl_formadd()  is  used  to  append sections when building a multipart/formdata HTTP POST (sometimes
       referred to as RFC2388-style posts). Append one section at a time until you've added all the sections
       you want included and then you pass the firstitem pointer as parameter to CURLOPT_HTTPPOST.  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 func-tion. function.
       tion. All list-data will be allocated by the function itself. You must call curl_formfree(3)  on  the
       firstitemP after the form post has been done to free the resources.

       Using  POST  with  HTTP 1.1 implies the use of a "Expect: 1__-continue" header.  You can disable this
       header with CURLOPT_HTTPHEADER as usual.

       First, there are some basics you need to understand about multipart/formdata posts.  Each  part  con-sists consists
       sists  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'll discuss what options you use to set  these  proper-ties properties
       ties 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 CURL-FORM_BUFFERLENGTH CURLFORM_BUFFERLENGTH
       FORM_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  doesn't  need  to keep it around after this function call. If the name isn't NUL-terminated, NULterminated,
              terminated, or if you'd like it to contain zero bytes, you must  set  its  length  with  CURL-FORM_NAMELENGTH. CURLFORM_NAMELENGTH.
              FORM_NAMELENGTH. The copied data will be freed by curl_formfree(3).

       CURLFORM_PTRNAME
              followed  by  a  string which provides the name 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 NUL-terminated, or if you'd like it to contain zero bytes, you
              must set its length with CURLFORM_NAMELENGTH.

       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 doesn't need to keep it around after this func-tion function
              tion 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 CURLFORM_CONTENTSLENGTH. The copied data will be freed by
              curl_formfree(3).

       CURLFORM_PTRCONTENTS
              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 NUL-terminated, or if you'd like it to  con-tain contain
              tain zero bytes, you must set its length  with CURLFORM_CONTENTSLENGTH.

       CURLFORM_CONTENTSLENGTH
              followed  by a long giving the length of the contents. Note that for CURLFORM_STREAM contents,
              this option is mandatory.

       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.

       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 CURL-FORM_FILE CURLFORM_FILE
              FORM_FILE arguments each followed by the filename (and each CURLFORM_FILE is allowed to have a
              CURLFORM_CONTENTTYPE).

       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 file
              name.

       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 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. (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  automati-cally automatically
              cally  generates.  The  list  must exist while the POST occurs, if you free it before the post
              completes you may experience problems.

              When you've passed the HttpPost pointer to  curl_easy_setopt(3)  (using  the  CURLOPT_HTTPPOST
              option),  you  must  not  free the list until after you've called curl_easy_cleanup(3) for the
              curl handle.

              See example below.

RETURN VALUE
       0 means everything was ok, non-zero means an error occurred corresponding to  a  CURL_FORMADD_*  con-stant constant
       stant defined in <curl/curl.h>

EXAMPLE
        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, record_length,
                     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);


SEE ALSO
       curl_easy_setopt(3), curl_formfree(3)



libcurl 7.9.8                                   24 June 2002                                 curl_formadd(3)