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Diffstat (limited to 'docs/libcurl/curl_formadd.3')
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diff --git a/docs/libcurl/curl_formadd.3 b/docs/libcurl/curl_formadd.3 new file mode 100644 index 00000000..6b272e05 --- /dev/null +++ b/docs/libcurl/curl_formadd.3 @@ -0,0 +1,217 @@ +.\" You can view this file with: +.\" nroff -man [file] +.\" $Id: curl_formadd.3,v 1.20 2009-08-04 12:02:27 bagder Exp $ +.\" +.TH curl_formadd 3 "24 June 2002" "libcurl 7.9.8" "libcurl Manual" +.SH NAME +curl_formadd - add a section to a multipart/formdata HTTP POST +.SH SYNOPSIS +.B #include <curl/curl.h> +.sp +.BI "CURLFORMcode curl_formadd(struct curl_httppost ** " firstitem, +.BI "struct curl_httppost ** " lastitem, " ...);" +.ad +.SH 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 \fIfirstitem\fP pointer as parameter to \fBCURLOPT_HTTPPOST\fP. +\fIlastitem\fP is set after each 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 \fIlastitem\fP pointer follow the real arguments. + +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(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, 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 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 NUL-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 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 NUL-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 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 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 contain zero bytes, +you must set its length with \fBCURLFORM_CONTENTSLENGTH\fP. +.IP CURLFORM_CONTENTSLENGTH +followed by a long giving the length of the contents. Note that for +\fICURLFORM_STREAM\fP contents, this option is mandatory. +.IP CURLFORM_FILECONTENT +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 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 \fICURLFORM_FILE\fP is allowed to have a +\fICURLFORM_CONTENTTYPE\fP). +.IP CURLFORM_CONTENTTYPE +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 +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 +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 +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 number of bytes in the buffer. +.IP CURLFORM_BUFFERLENGTH +is used in combination with \fICURLFORM_BUFFER\fP. The parameter is a +long which gives the length of the buffer. +.IP CURLFORM_STREAM +Tells libcurl to use the \fICURLOPT_READFUNCTION\fP callback to get data. The +parameter you pass to \fICURLFORM_STREAM\fP 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 \fICURLFORM_FILENAME\fP parameter as well. Note that when +using \fICURLFORM_STREAM\fP, \fICURLFORM_CONTENTSLENGTH\fP must also be set +with the total expected length of the part. (Option added in libcurl 7.18.2) +.IP CURLFORM_ARRAY +Another possibility to send options to curl_formadd() is the +\fBCURLFORM_ARRAY\fP 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 \fBCURLFORM_END\fP. +.IP CURLFORM_CONTENTHEADER +specifies extra headers for the form POST section. This takes a curl_slist +prepared in the usual way using \fBcurl_slist_append\fP 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've passed the HttpPost pointer to \fIcurl_easy_setopt(3)\fP (using +the \fICURLOPT_HTTPPOST\fP option), you must not free the list until after +you've called \fIcurl_easy_cleanup(3)\fP for the curl handle. + +See example below. +.SH RETURN VALUE +0 means everything was ok, non-zero means an error occurred corresponding +to a CURL_FORMADD_* constant defined in +.I <curl/curl.h> +.SH EXAMPLE +.nf + + 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); + +.SH "SEE ALSO" +.BR curl_easy_setopt "(3), " +.BR curl_formfree "(3)" |