Как мне преобразовать "Long File Name.pas" в "longfi~1.pas"?

Попробуйте эти процедуры:

Function GetShortFileName(Const FileName : String) : String;
var

aTmp: array[0..255] of char;

begin

if GetShortPathName(PChar(FileName),aTmp,Sizeof(aTmp)-1)=0 then

Result:= FileName

else

Result:=StrPas(aTmp);

end;

Function GetLongFileName(Const FileName : String) : String;
var

aInfo: TSHFileInfo;

begin

if SHGetFileInfo(PChar(FileName),0,aInfo,Sizeof(aInfo),SHGFI_DISPLAYNAME)<>0 then

Result:= String(aInfo.szDisplayName)

else

Result:= FileName;

end;

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