But why use the GET method as opposed to POST?
The HTML/Ada interface demo on my website uses the
POST method, which sends the enctype date into the
program via stdin, and this eliminates the command
line problem entirely.
See:
http://unicoi.kennesaw.edu/~rconn/index.html
POST is what I use for all of my websites. The O'Reilly
books even say that it is preferred.
----------------------------------
Richard Conn, ASE and PAL Manager
http://xenadu.home.mindspring.com/
> -----Original Message-----
> From: Team Ada: Ada Advocacy Issues (83 & 95)
> [mailto:[log in to unmask]]On Behalf Of Robert C. Leif, Ph.D.
> Sent: Saturday, December 04, 1999 5:58 PM
> To: [log in to unmask]
> Subject: Rational A.5 Command Line and HTML
>
>
> From: Bob Leif
> To: Readers of Comp.Lang.Ada and Team-Ada
>
> Disclaimer: Although, I had this problem with an ObjectAda compiler, it is
> neither a bug or a design error. It is an Ada problem and
> therefore relevant
> to these forums.
>
> There is now obvious interest in XML-HTML. In fact, concerning
> the presently
> popular subject, "What the competition looks like". There will
> and probably
> are now more individuals conversant with HTML-XML than any of the present
> programming languages. The tools to build web-pages will have a very large
> market compared to any programming language development system.
>
> One major impediment to interfacing with HTML is in the package
> Ada.Command_Line. The HTML statement,
> <FORM method="Get" action="file:///C:\Ada_Work/com_line.exe"> is a
> reasonable key to this problem. It produces a Command_Line string and does
> invoke the com_line program shown below. Unfortunately,
> Command_Line.Argument_Count does not work with the Command_Line string.
> The Get method concatenates a '?' directly after the program name.
> ----------------------------------------------------------------
> HTML 4.01 Specification
> W3C Proposed Recommendation
> This version:
> http://www.w3.org/TR/1999/PR-html40-19990824
> (plain text [786Kb], gzip’ed tar archive of HTML files [367Kb], a .zip
> archive of
> HTML files [400Kb], gzip’ed Postscript file [740Kb, 387 pages], a PDF file
> [3Mb])
> 17.13.3 Processing form data, Page 247
>
> "However, HTML 4.01 user agents must support
> the established conventions in the following cases:
> If the method is "get" and the action is an HTTP URI, the user agent takes
> the value of action, appends a ‘?’ to it, then appends the form data set
> [p.246] ,encoded using the "application/x-www-form-urlencoded"
> content type
> [p.247] .The user agent then traverses the link to this URI. In this
> scenario, form data are restricted to ASCII codes."
> --------------------------------------------------------------
> I have included a very simple HTML Form (Com_Line_Small) below.
> It produces
> the equivalent of "C:\Ada_Work\com_line.exe?TEST=Hello".
> I proved under Windows that this did not work with a Com_line.Bat batch
> program with the line above as its only text. However, the simple
> insertion
> of a space between the program and the '?' works.
> C:\Ada_Work\com_line.exe ?TEST=Hello
>
> The output of my com_line_small.Bat is as follows:
>
> C:\Ada_Work\com_line_Small.exe?TEST=Hello
> The DOS Window shows: Bad command or file name
>
> However, the program does run when actuated through the HTML
> form; with the
> number of arguments equal to 0.
> C:\Ada_Work\com_line.exe equals the Command_Line
> This Program is Com_Line
>
> The number of arguments = 0
> -----------------------------------------------
>
> C:\Ada_Work>C:\Ada_Work\com_line.exe ?TEST=Hello
> The DOS Window shows that the program has executed
>
> C:\ADA_WORK\COM_LINE.EXE equals the Command_Line
> The number of arguments = 1
> Argument 1 is ?TEST=Hello
>
> I do not believe this is the fault of the ObjectAda compiler.
> The Ada 95 LRM really does not define what a command line is. The
> Rationale
> on page A-32 states:
> A:5 Command Line
> "The package Ada.Command_Line provides an Ada program with a
> simple means of
> accessing any arguments of the command which invoked it. The package also
> enables the program to set a return status. Clearly the interpretation of
> these facilities depends very much on the underlying operating system."
>
> The question is which operating system, Windows or HTTP? The above problem
> is neither a bug nor a design mistake. It is correct for its intended use,
> Windows. However, it does not work with HTTP. I do believe in
> hindsight that
> a function that returns the entire command_line including the program name
> should be added. In view of the significance of HTML-XML, I
> believe that it
> would be worthwhile to modify the Aonix Command_Line or any other Ada
> compiler to work with the output of HTML Get.
>
> Can any of the Ada compilers read and process a command_line that does NOT
> have a space after the name of the executable? If you wish to test this,
> please feel fee to use the Ada program and HTML page below.
>
> ----------------------------------------------------------
> --Robert C. Leif, Ph.D & Ada_Med
>
> --2 Dec. 1999
> --Last update 3 Dec. 1999
>
> --File name Com_Line_Small.Adb
>
> --e-mail [log in to unmask]
>
> with Ada.Text_Io;
> with Ada.Exceptions;
> with Ada.Command_Line;
> with Interfaces.C.Strings;
> procedure Com_Line_Small is
> Prog_Location : constant String := "Com_Line_Small";
> package T_Io renames Ada.Text_Io;
> package Command_Line renames Ada.Command_Line;
> Num_Args : Natural := 1;
> --Com_Line_Var : String := Command_Line.Command_Name;
> Exit_Char : Character := 'x';
> ------------------------------------------------------------------
> --sugested by Randy Brukardt
> function Get_Command_Line return Interfaces.C.Strings.Chars_Ptr;
> pragma Import (
> Convention => Win32,
> Entity => Get_Command_Line,
> External_Name => "GetCommandLineA");
> ----------------------------------------------------------------
> begin --Com_Line_Small
> --then Call:
> T_Io.Put_Line("Windows way (Randy Brukardt) to get the Command_Line:");
> T_Io.Put_Line(Interfaces.C.Strings.Value(Get_Command_Line));
> --returns a string
>
> Num_Args := Command_Line.Argument_Count;
> T_Io.Put_Line("");
> T_Io.Put_Line("Ada way to get the Command_Line:");
> T_Io.Put_Line(Command_Line.Command_Name);
> T_Io.Put_Line("This Program is " & Prog_Location);
> T_Io.Put_Line("");
> T_Io.Put_Line("The number of arguments = "
> & Natural'Image(Num_Args));
>
> if Num_Args >= 1 then
> for I in 1..Num_Args loop
> T_Io.Put_Line("Argument " & Natural'Image(I) & " is "
> & Command_Line.Argument (Number => I));
> end loop;
> end if;
> T_Io.Put_Line("Ending Com_Line_Small Test program");
> T_Io.Put_Line("Ending " & Prog_Location);
> T_Io.Get(Exit_Char);
> exception
> when O: others =>
> T_Io.Put_Line(Ada.Exceptions.Exception_Information (O));
> T_Io.Put_Line(Ada.Exceptions.Exception_Message (O));
>
> end Com_Line_Small;
> ----------------------------------------------------------------
> Output:
>
> Windows way (Randy Brukardt) to get the Command_Line:
> "C:\Ada_Work\com_line_small.exe"
>
> Ada way to get the Command_Line:
> C:\Ada_Work\com_line_small.exe
> This Program is Com_Line_Small
>
> The number of arguments = 0
> Ending Com_Line_Small Test program
> Ending Com_Line_Small
> ---------------------------------------------------
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
> <HTML>
> <HEAD>
> <TITLE>
> Com_Line_Small Test
> </TITLE>
> <meta http-equiv="Content-Type" content="text/html;
> charset=Latin1">
>
> <meta http-equiv="Content-Language" content="en-us">
>
> <Bass href="C:\Ada_Work">
> </HEAD>
> <BODY aLink=#ff0000 background="" bgColor=#ffffff link=#0000ff
> text=#000000 vLink=#800080>
>
> <!--How do I get the string named test into the-->
> <!--command line of HTML_Ada?-->
> <OBJECT classid="File:///C:\Ada_Work\com_line_Small.exe"
> height=40 width=40 title=Com_Line>
> <PARAM NAME="TEST" VALUE="Hello">
> </OBJECT>
>
> <FORM method="Get"
> action="file:///C:\Ada_Work/com_line_Small.exe">
>
> <p>
> <input TYPE="text" NAME="TEST" SIZE="10"
> MAXLENGTH="15"
> VALUE="Hello">
> </p>
>
>
> <INPUT type=submit value="Submit Form">
> <INPUT name=Reset type=reset value="Reset Form">
>
> </FORM>
> </BODY>
> </HTML>