Mega Code Archive
To read the proxy information
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Title: to read the proxy information
Friends,
most tasks that works with internet, requires to read the current proxy settings from computer before connect to remote server.
Today I want to show two way to read this information.
1. to use registry
this is easy and fast way but note that if in future the Microsoft will change a key where proxy stored, you must change your code too:-)
var
Handle: HKey;
Buffer: array[0..256] of Char;
BufSize: Integer;
DataType: Integer;
begin
if RegOpenKeyEx(HKEY_CURRENT_USER,
'SOFTWAREMicrosoftWindowsCurrentVersionInternet Settings',
0, KEY_READ, Handle) = ERROR_SUCCESS then
begin
BufSize := SizeOf(Buffer);
DataType := reg_sz;
if RegQueryValueEx(Handle, 'ProxyServer', nil, @DataType, @Buffer, @BufSize) = ERROR_SUCCESS then
ProxyServer := Buffer;
BufSize := SizeOf(Integer);
if RegQueryValueEx(Handle, 'ProxyEnable', nil, @DataType, @i, @BufSize) = ERROR_SUCCESS then
UseProxyServer := (i 0);
RegCloseKey(Handle);
end;
end;
2. to use WinInet library
this is more correct way to get an information but require IE 3.x (or higher)
var
ProxyInfo: PInternetProxyInfo;
Len: LongWord;
begin
Len := 4096;
GetMem(ProxyInfo, Len);
try
if InternetQueryOption(nil, INTERNET_OPTION_PROXY, ProxyInfo, Len) then
if ProxyInfo^.dwAccessType = INTERNET_OPEN_TYPE_PROXY then
begin
UseProxyServer := True;
ProxyServer := ProxyInfo^.lpszProxy
end
finally
FreeMem(ProxyInfo);
end;
end;
Now if proxy used, we'll receive in ProxyServer variable similar string:
"ftp=proxy.domain.com:8082;gopher=proxy.domain.com:8083;http=proxy.domain.com:8080;https=proxy.domain.com:8081"
where domain.com is our proxy.
So as you see, now we must parse this string for correct protocol (http/ftp etc) and to get the proxy server and port number.
For example:
if UseProxyServer and (ProxyServer '') then
begin
i := Pos('http=', ProxyServer);
if (i 0) then
begin
Delete(ProxyServer, 1, i+4);
j := Pos(';', ProxyServer);
if (j 0) then
ProxyServer := Copy(ProxyServer, 1, j-1);
end;
i := Pos(':', ProxyServer);
if (i 0) then
begin
j := Pos(' ', ProxyServer);
if(j=0) then
begin
j:=length(proxyserver)+1;
end;
ProxyPort := StrToInt(Copy(ProxyServer, i+1, j-i-1));
ProxyServer := Copy(ProxyServer, 1, i-1)
end
end;
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