unlock.bas

'
'  Author:  Terence Kelly
'  Date:    5 September 1995
'
'  This module serves exactly one purpose in life:  it helps you
'  "unlock" the WEBRTI program by deleting that program's lock file.
'  The name of the file is stored in a global variable.  A simple
'  message is returned to the Web client indicating whether the
'  unlock operation is successful or not.
'

Global Const strLockFile$ = "C:\HTTPD\HTDOCS\WEBRTI\WEBRTI.LOK"

Function Click_Here () As String
    '
    '  Return a string consisting of an HTML document containing a
    '  button to click to unlock the RTI board.
    '

    URL$ = "http://piper.princeton.edu/cgi-win/unlock.exe?unlock"
    Link$ = "<a href=" & Chr$(34) & URL$ & Chr$(34) & ">UNLOCK</a>"

    B$ = HTML_H1("Unlock the WEBRTI program") & CRLF()
    B$ = B$ & HTML_H2("Current lockfile:") & CRLF()
    B$ = B$ & HTML_pre(FileContents(strLockFile$)) & CRLF() & CRLF()
    B$ = B$ & "<p>" & CRLF() & "If you are <em>absolutely sure</em> "
    B$ = B$ & "that the " & CRLF()
    B$ = B$ & "WEBRTI program is really not in use, i.e. that the "
    B$ = B$ & "program is " & CRLF()
    B$ = B$ & "erroneously locked (due e.g. to a server or "
    B$ = B$ & "executable crash), " & CRLF()
    B$ = B$ & "then click on the UNLOCK link below." & CRLF()
    B$ = B$ & "</p>" & CRLF()
    B$ = B$ & HTML_H1(Link$) & CRLF()

    Click_Here = HTML_document("Unlock the WEBRTI program", B$)

End Function

Sub Main ()
    '
    '  Remove lock file.  Return a happy or sad message to the
    '  client.
    '

    strCmdLine$ = Command$
    strOutputFile$ = Split(strCmdLine$, 3, " ")
    strURLArgs$ = Split(strCmdLine$, 4, " ")

    If strURLArgs$ <> "unlock" Then
        strReturn = Click_Here()
    Else
        strReturn = Unlock_RTI()
    End If
    
    Filenumber% = FreeFile
    Open strOutputFile$ For Output As #Filenumber%
    Print #Filenumber%, strReturn
    Close #Filenumber%

End Sub

Function Unlock_RTI ()
    '
    '  Unlock the RTI board by deleting the lock file, return a
    '  diagnostic message to the user.
    '

    If Dir$(strLockFile$) <> "" Then
        Kill strLockFile
        Title$ = "Unlock succeeded"
        MSG$ = HTML_H1("Lock file removed")
    Else
        Title$ = "Unlock failed"
        MSG$ = HTML_H1("Lock file not found")
    End If

    Unlock_RTI = HTML_document(Title$, MSG$)

End Function