![]() ![]() The -download option only changes how the response body is treated.dco is shorthand for -download -continue -output. There are multiple useful ways to use piping: Or -compress, -x to compress the request body. You may also use -chunked to enable streaming via chunked transfer encoding If you provide Content-Length, then the request body is streamed without buffering. The universal method for passing request data is through redirected stdinīy default, stdin data is buffered and then with no further processing used as the request body. ![]() There are three methods for passing raw request data: piping via stdin, These two approaches for specifying request data (i.e., structured and raw) cannot be combined. In addition to crafting structured JSON and forms requests with the request items syntax, you can provide a raw request body that will be sent without further processing. The response headers are downloaded always, even if they are not part of the output Raw request body Therefore, bandwidth and time isn’t wasted downloading the body which you don’t care about. Since you are only printing the HTTP headers here, the connection to the server is closed as soon as all the response headers have been received. For example instead of using a static string as the value for some header, you can use operator Using file contents as values for specific fields is a very common use case, which can be achieved through adding the suffix to Raw request body is a mechanism for passing arbitrary request data. Note that the structured data fields aren’t the only way to specify request data: For example or With -form, the presence of a file field results in a -multipart request Useful when sending JSON and one or more fields need to be a Boolean, Number, nested Object, or an Array, e.g., meals:='' or pies:= (note the quotes)įile upload fields available with -form, -f and -multipart. Request data fields to be serialized as a JSON object (default), to be form-encoded (with -form, -f), or to be serialized as multipart/form-data (with -multipart) X-API-Token:123Īppends the given name/value pair as a querystring parameter to the URL. Otherwise, use application/x-HTTP header, e.g. The moral of the story is, if you have binary (non-alphanumeric) data (or a significantly sized payload) to transmit, use multipart/form-data. Why not use multipart/form-data all the time? For short alphanumeric values (like most web forms), the overhead of adding all of the MIME headers is going to significantly outweigh any savings from more efficient binary encoding. The MIME spec gives us more options when representing the value payload - we can choose a more efficient encoding of binary data to save bandwidth (e.g. Each part has its own set of MIME headers like Content-Type, and particularly Content-Disposition, which can give each part its "name." The value piece of each name/value pair is the payload of each part of the MIME message. Parts are separated by a particular string boundary (chosen specifically so that this boundary string does not occur in any of the "value" payloads). With this method of transmitting name/value pairs, each pair is represented as a "part" in a MIME message (as described by other answers). That's where multipart/form-data comes in. For large binary files, tripling the payload is going to be highly inefficient. That means that for each non-alphanumeric byte that exists in one of our values, it's going to take three bytes to represent it. ![]() non-alphanumeric characters are replaced by `%HH', a percent sign and two hexadecimal digits representing the ASCII code of the character MyVariableOne=ValueOne&MyVariableTwo=ValueTwo To understand why, you have to look at what each is doing under the covers.įor application/x-www-form-urlencoded, the body of the HTTP message sent to the server is essentially one giant query string - name/value pairs are separated by the ampersand ( &), and names are separated from values by the equal symbal ( =). Depending on the type and amount of data being transmitted, one of the methods will be more efficient than the other. The purpose of both of those types of requests is to send a list of name/value pairs to the server. The MIME types you mention are the two Content-Type headers for HTTP POST requests that user-agents (browsers) must support. Otherwise, use application/x-www-form-urlencoded.” “The moral of the story is, if you have binary (non-alphanumeric) data (or a significantly sized payload) to transmit, use multipart/form-data. application/x-www-form-urlencoded and multipart/form-data. Nice answer on stackoverflow to the question of when to use one or the other content-types for POSTing data, viz. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |