Command
	isheadsub

Purpose
	Submits (posts) headers for future requests to a server.

Aliases
	isheadersubmit, isheadsub, ishsubmit, ishsub, ishs

Syntax
	isheadsub <name>  <parm> [<parm> [<parm> ...] ]

Options
	None.


Arguments
	<name>	This is the name of the internet session, also called session. A session
		by this name must have already started with the isstart command and connected to
		a server with the iscon command.

		This argument can be supplied using a constant, variable, expression, function call,
		inline command, or a combination of these, all resulting into a single value of type str.
		If a constant is used, it should be enclosed in double quotes.

	<parm>	A parameter to be added to the header. Parameters are specified using a category and/or
		a name and/or a value.


	<parm_category>	Category of a parameter.

	<parm_name>	Name of a parameter.

	<parm_value>	Value of the parameter.

		Parameters to the header can be passed in any one of the following formats.

		<parm_category>

			The <parm_name> and <parm_value> are absent. An example of such parameter is "HttpOnly".

		<parm_category>: <parm_name>

			The <parm_value> is absent. An example of such parameter is "Accept: text/html".

		<parm_category>: <parm_name>=<parm_value>

			All <parm_category>, <parm_name> and <parm_value> are present. An example
			of such parameter is "Content-Type: charset=utf-8".

		<parm_name>=<parm_value>

			The <parm_category> is absent. An example of such parameter is "path=/".


		A parameter in any format can be supplied using a constant, variable, expression, function call,
		inline command, or a combination of these, all resulting into a single value of type str.
		If a constant is used, it should be enclosed in double quotes.

		Multiple parameters can be specified in the same command.

		Parameters are optional. If no parameters are specified, the existing headers will be written
		to stream output.

Stream Input	
	Ignored.

Stream Output
	The resulting headers are written here.

Stream Error
	Any errors are listed here.

Description
	This command submits or posts the headers associated with all future requests to
	an internet server. The session must have already been started with the isstart command,
	and connected to a server with the iscon command.

	The submitted headers are written to stream output.
	
	
Restrictions


Valid Examples
	isstart "mail"
	iscon "mail" "http://mail.yourfavoritesite.com"
	isheadsub "mail" "sessionid=389Kl0Juuh6HeK0L"
	issub "mail" "/login.html" "login=you@yourfavoritesite.com" "password=9KLo650"
	isret "mail" "/mymail.html"


	Will submit the login form with login, password and session id.


	isstart "mail"
	iscon "mail" "http://mail.yourfavoritesite.com"
	var str header
	isheadret "mail" > $header

	Will retrieve the headers associated with the default document serverd by the internet server at
	"http://mail.yourfavoritesite.com". If this site returns a sessionid in the header in the format
	"sessionid=389Kl0Juuh6HeK0L;", it can now be automatically extracted and set for the next request
	as follows.

	var str sessionid
	stex -c -r "^sessionid=&\;^" $header > $sessionid
	stex "[^;^" $sessionid > null
	isheadsub "mail" $sessionid


Invalid Examples
	isstart "accesslog"
	isheadsub "accesslog" 

	Will produce an error. Session "accesslog" is not connected to a server.


See Also
IS
isheadret
isstart
isend
iscon
isdiscon
issub
issave
stex
SS_ISCookies