Contributor: GREG ESTABROOKS
{
There are 2 ways that I can think of off hand. One is to execute
COMMAND.COM with the parameter '/K PROMPT [Whatever]' OR You could
create your own program enviroment and then add/edit as many enviroment
variables as you have memory for. The following program demonstrates
this. It creates its own enviroment , then copies the old info to it
but changes the prompt to whatever you want. After the shell it
releases the memory:
}
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PROGRAM PromptDemo; { Apr 18/94, Greg Estabrooks. }
{$M 16840,0,0} { Reserved some memory for the shell. }
USES CRT, { IMPORT Clrscr,Writeln. }
DOS; { IMPORT Exec. }
PROCEDURE ShellWithPrompt( Prompt :STRING );
{ Routine to allocate a temporary Enviroment }
{ with our prompt and the execute COMMAND.COM. }
{ NOTE: This does NO error checking. }
VAR
NewEnv :WORD; { Points to our newly allocated env. }
OldEnv :WORD; { Holds Old Env Segment. }
EnvPos :WORD; { Position inside our enviroment. }
EnvLp :WORD; { Variable to loop through ENVStrings. }
TempStr:STRING; { Holds temporary EnvString info. }
BEGIN
ASM
Mov AH,48ドル { Routine to allocate memory. }
Mov BX,1024 { Allocate 1024(1k) of memory. }
Int 21ドル { Call DOS to allocate memory. }
Mov NewEnv,AX { Save segment address of our memory. }
END;
EnvPos := 0; { Initiate pos within our Env. }
FOR EnvLp := 1 TO EnvCount DO { Loop through entire enviroment. }
BEGIN
TempStr := EnvStr(EnvLp); { Retrieve Envirment string. }
IF Pos('PROMPT=',TempStr) 0 THEN { If its our prompt THEN .... }
TempStr := 'PROMPT='+Prompt+#0 { Create our new prompt. }
ELSE { .... otherwise......... }
TempStr := TempStr + #0; { Add NUL to make it ASCIIZ compatible. }
Move(TempStr[1],Mem[NewEnv:EnvPos],Length(TempStr)); { Put in Env. }
INC(EnvPos,Length(TempStr)); { Point to new position in Enviroment. }
END;{For}
OldEnv := MemW[PrefixSeg:2ドルC];{ Save old enviroment segment. }
MemW[PrefixSeg:2ドルC] := NewEnv;{ Point to our new enviroment. }
SwapVectors; { Swap Int vectors in case of conflicts.}
Exec(GetEnv('COMSPEC'),''); { Call COMMAND.COM. }
SwapVectors; { Swap em back. }
MemW[PrefixSeg:2ドルC] := OldEnv;{ Point back to old enviroment. }
ASM
Push ES { Save ES. }
Mov AH,49ドル { Routine to deallocate memory. }
Mov ES,NewEnv { Point ES to area to deallocate. }
Int 21ドル; { Call DOS to free memory. }
Pop ES { Restore ES. }
END;
END;{ShellWithPrompt}
BEGIN
Clrscr; { Clear the screen. }
Writeln('Type EXIT to return');{ Show message on how to exit shell. }
ShellWithPrompt('[PromptDemo] $P$G'); { shell to DOS with our prompt. }
END.{PromptDemo}
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