Category : Miscellaneous Language Source Code
Archive   : E!518.ZIP
Filename : LOADEXT.PAS

Program Loadext;
{$IFDEF DEBUG}
{$A-,B-,D+,F+,I-,N-,R-,S-,V-,L+,O-}
{$ELSE}
{$A-,B-,D-,F+,I-,N-,R-,S-,V-,L-,O-}
{$ENDIF}

{ Please see LOADEXT.DOC }
{ This source file is provided to show how easy it is to write a new }
{ function using the E! API }

Uses Dos, Crt, Api;

VAR

IntStr : string[3]; { Interrupt number used by E! }
IntNum : byte; { " " " " " }
valretcode : integer;
FileName : pathstr;
NamePtr : ^pathstr;
Ext : string[3];

Function Lastpos(needle,haystack:string;start:integer):integer;
{ -This function is extracted from the E! source code }
{ It returns the the last position of needle in haystack }

var
textbuffer,
needlebuffer : string;
limit,newpos,
len1,len2 : integer;
i : byte;

begin
len2:=Length(needle);
limit:=Length(haystack) - len2 + 1;
if start < 1 then begin
LastPos:=0;
Exit;
end
else if start > limit then
start:=limit;
Delete(haystack,start + len2, 255);
len1:=Length(haystack);
textbuffer[0]:=Char(len1);
needlebuffer[0]:=Char(len2);
for i:=1 to len1 do
textbuffer[Succ(len1) - i]:=haystack[i];
for i:=1 to len2 do
needlebuffer[Succ(len2) - i]:=needle[i];
newpos:=Pos(needlebuffer,textbuffer);
if newpos = 0 then
LastPos:=0
else
LastPos:=Succ(len1 - Pred(newpos) - len2);
end;


begin
{ Is E! present ? }
IntStr:=GetEnv('E!PRESENT');
{ Retrieve the number of the interrupt used by E! }
if IntStr = '' then
Halt;
Val(IntStr, IntNum, valretcode);
if valretcode <> 0 then
Halt
else
E_Vec:=IntNum;
{ Is E! busy ? }
if not Is_E_Idle then
Halt;
{ Get the name of the current file }
NamePtr:=Request_E_Address(NAME_REQUEST);
FileName:=NamePtr^;
{ ... and its extension }
Ext:=Copy(FileName, Succ(LastPos('.', FileName, Length(FileName))), 3);
if Ext = '' then
halt;
{ Load the relevant profile }
RegisterCommand('PRO '+ Ext);
END.