curl/docs/cmdline-opts/form.d
Daniel Stenberg ce6e3e5320
cmdline-opts: made the 'Added:' field mandatory
Since "too old" versions are no longer included in the generated man
page, this field is now mandatory so that it won't be forgotten and then
not included in the documentation.

Closes #7786
2021-09-28 16:20:12 +02:00

142 lines
4.9 KiB
D

Long: form
Short: F
Arg: <name=content>
Help: Specify multipart MIME data
Protocols: HTTP SMTP IMAP
Mutexed: data head upload-file
Category: http upload
Example: --form "name=curl" --form "file=@loadthis" $URL
Added: 5.0
---
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 means 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.
Tell curl to read content from stdin instead of a file by using - as
filename. This goes for both @ and < constructs. When stdin is used, the
contents is buffered in memory first by curl 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, such data is sent as chunks by HTTP and rejected
by IMAP.
Example: send an image to an HTTP server, where \&'profile' is the name of the
form-field to which the file portrait.jpg will be the input:
curl -F profile=@portrait.jpg https://example.com/upload.cgi
Example: send your name and shoe size in two text fields to the server:
curl -F name=John -F shoesize=11 https://example.com/
Example: send your essay in a text field to the server. Send it as a plain
text field, but get the contents for it from a local file:
curl -F "story=<hugefile.txt" https://example.com/
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=@\\"local,file\\";filename=\\"name;in;post\\"" example.com
or
curl -F 'file=@"local,file";filename="name;in;post"' 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 '= <body>HTML message</body>;type=text/html' \\
.br
-F '=)' -F '=@textfile.txt' ... smtp://example.com
Data can be encoded for transfer using encoder=. Available encodings are
*binary* and *8bit* that do nothing else than adding the corresponding
Content-Transfer-Encoding header, *7bit* that only rejects 8-bit characters
with a transfer error, *quoted-printable* and *base64* 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.