Long: form Short: F Arg: Help: Specify multipart MIME data Protocols: HTTP SMTP IMAP Mutexed: data head upload --- For HTTP protocol family, this lets curl emulate a filled-in form in which a user has pressed the submit button. This causes curl to POST data using the Content-Type multipart/form-data according to RFC 2388. For SMTP and IMAP protocols, this is the mean to compose a multipart mail message to transmit. This enables uploading of binary files etc. To force the 'content' part to be a file, prefix the file name with an @ sign. To just get the content part from a file, prefix the file name with the symbol <. The difference between @ and < is then that @ makes a file get attached in the post as a file upload, while the < makes a text field and just get the contents for that text field from a file. Example: to send an image to an HTTP server, where \&'profile' is the name of the form-field to which portrait.jpg will be the input: curl -F profile=@portrait.jpg https://example.com/upload.cgi To read content from stdin instead of a file, use - as the filename. This goes for both @ and < constructs. If stdin is not attached to a regular file, it is buffered first to determine its size and allow a possible resend. Defining a part's data from a named non-regular file (such as a named pipe or similar) is unfortunately not subject to buffering and will be effectively read at transmission time; since the full size is unknown before the transfer starts, data is sent as chunks by HTTP and rejected by IMAP. You can also tell curl what Content-Type to use by using 'type=', in a manner similar to: curl -F "web=@index.html;type=text/html" example.com or curl -F "name=daniel;type=text/foo" example.com You can also explicitly change the name field of a file upload part by setting filename=, like this: curl -F "file=@localfile;filename=nameinpost" example.com If filename/path contains ',' or ';', it must be quoted by double-quotes like: curl -F "file=@\\"localfile\\";filename=\\"nameinpost\\"" example.com or curl -F 'file=@"localfile";filename="nameinpost"' example.com Note that if a filename/path is quoted by double-quotes, any double-quote or backslash within the filename must be escaped by backslash. Quoting must also be applied to non-file data if it contains semicolons, leading/trailing spaces or leading double quotes: curl -F 'colors="red; green; blue";type=text/x-myapp' example.com You can add custom headers to the field by setting headers=, like curl -F "submit=OK;headers=\\"X-submit-type: OK\\"" example.com or curl -F "submit=OK;headers=@headerfile" example.com The headers= keyword may appear more that once and above notes about quoting apply. When headers are read from a file, Empty lines and lines starting with '#' are comments and ignored; each header can be folded by splitting between two words and starting the continuation line with a space; embedded carriage-returns and trailing spaces are stripped. Here is an example of a header file contents: # This file contain two headers. .br X-header-1: this is a header # The following header is folded. .br X-header-2: this is .br another header To support sending multipart mail messages, the syntax is extended as follows: .br - name can be omitted: the equal sign is the first character of the argument, .br - if data starts with '(', this signals to start a new multipart: it can be followed by a content type specification. .br - a multipart can be terminated with a '=)' argument. Example: the following command sends an SMTP mime e-mail consisting in an inline part in two alternative formats: plain text and HTML. It attaches a text file: curl -F '=(;type=multipart/alternative' \\ .br -F '=plain text message' \\ .br -F '= HTML message;type=text/html' \\ .br -F '=)' -F '=@textfile.txt' ... smtp://example.com Data can be encoded for transfer using encoder=. Available encodings are \fIbinary\fP and \fI8bit\fP that do nothing else than adding the corresponding Content-Transfer-Encoding header, \fI7bit\fP that only rejects 8-bit characters with a transfer error, \fIquoted-printable\fP and \fIbase64\fP that encodes data according to the corresponding schemes, limiting lines length to 76 characters. Example: send multipart mail with a quoted-printable text message and a base64 attached file: curl -F '=text message;encoder=quoted-printable' \\ .br -F '=@localfile;encoder=base64' ... smtp://example.com See further examples and details in the MANUAL. This option can be used multiple times.