_strrchr的Delphi的实现

接续上一篇文章，这次是_strrchr的实现，返回反向查找字符的结果，返回值是个指针
function _strrchr(p1 : pchar; ch1 :char) : pchar; Cdecl;
var
tp1 : pchar;
begin
if p1^ = #0 then
begin
result := 0;
exit;
end;
tp1 := p1;
while tp1^ <> #0 do inc(tp1);
while tp1 >= p1 do
begin
dec(tp1);
if tp1^ = ch1 then break;
end;
result := tp1;
end;