Difference between revisions of "fphttpclient"
From Free Pascal wiki
Jump to navigationJump to searchm |
(Added getting external ip address sample) |
||
| Line 23: | Line 23: | ||
<syntaxhighlight> | <syntaxhighlight> | ||
s := TFPCustomHTTPClient.SimpleGet('http://a_site/a_page'); | s := TFPCustomHTTPClient.SimpleGet('http://a_site/a_page'); | ||
| + | </syntaxhighlight> | ||
| + | |||
| + | === Get external IP address === | ||
| + | If your computer is connected to the internet via a LAN (cabled or wireless), the IP address of your network card most probably is not your external IP address. | ||
| + | |||
| + | You can retrieve your external IP address from e.g. your router or an external site. The code below tries to get it from an external site (thanks to JoStudio on the forum for the inspiration: [http://lazarus.freepascal.org/index.php/topic,17506.msg110917.html#msg110917]): | ||
| + | <syntaxhighlight> | ||
| + | {$mode objfpc}{$H+} | ||
| + | |||
| + | uses | ||
| + | Classes, SysUtils, fphttpclient, RegexPr; | ||
| + | |||
| + | function GetExternalIPAddress: string; | ||
| + | var | ||
| + | HTTPClient: TFPHTTPClient; | ||
| + | IPRegex: TRegExpr; | ||
| + | RawData: string; | ||
| + | begin | ||
| + | try | ||
| + | HTTPClient:=TFPHTTPClient.Create(nil); | ||
| + | IPRegex:=TRegExpr.Create; | ||
| + | try | ||
| + | //returns something like: | ||
| + | { | ||
| + | <html><head><title>Current IP Check</title></head><body>Current IP Address: 44.151.191.44</body></html> | ||
| + | } | ||
| + | RawData:=HTTPClient.Get('http://checkip.dyndns.org'); | ||
| + | // adjust for expected output; we just capture the first IP address now: | ||
| + | IPRegex.Expression:=RegExprString('\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b'); | ||
| + | //or | ||
| + | //\b(?:\d{1,3}\.){3}\d{1,3}\b | ||
| + | if IPRegex.Exec(RawData) then | ||
| + | begin | ||
| + | result:=IPRegex.Match[0]; | ||
| + | end | ||
| + | else | ||
| + | begin | ||
| + | result:='Got invalid results getting external IP address. Details:'+LineEnding+ | ||
| + | RawData; | ||
| + | end; | ||
| + | except | ||
| + | on E: Exception do | ||
| + | begin | ||
| + | result:='Error retrieving external IP address: '+E.Message; | ||
| + | end; | ||
| + | end; | ||
| + | finally | ||
| + | HTTPClient.Free; | ||
| + | IPRegex.Free; | ||
| + | end; | ||
| + | end; | ||
| + | |||
| + | begin | ||
| + | writeln('External IP address:'); | ||
| + | writeln(GetExternalIPAddress); | ||
| + | end. | ||
</syntaxhighlight> | </syntaxhighlight> | ||
[[Category:FPC]] | [[Category:FPC]] | ||
[[Category:Networking]] | [[Category:Networking]] | ||
Revision as of 13:21, 27 January 2013
fphttpclient is supplied with FPC as part of the fcl-web package, and can be used by itself as well.
Examples
Get body of an HTTP page
uses fphttpclient;
Var
S : String;
begin
With TFPHttpClient.Create(Nil) do
try
S:=Get(ParamStr(1));
finally
Free;
end;
Writeln('Got : ',S);
end.If you want to write even less lines of code, in FPC 2.7.1 you can use the class method:
s := TFPCustomHTTPClient.SimpleGet('http://a_site/a_page');Get external IP address
If your computer is connected to the internet via a LAN (cabled or wireless), the IP address of your network card most probably is not your external IP address.
You can retrieve your external IP address from e.g. your router or an external site. The code below tries to get it from an external site (thanks to JoStudio on the forum for the inspiration: [1]):
{$mode objfpc}{$H+}
uses
Classes, SysUtils, fphttpclient, RegexPr;
function GetExternalIPAddress: string;
var
HTTPClient: TFPHTTPClient;
IPRegex: TRegExpr;
RawData: string;
begin
try
HTTPClient:=TFPHTTPClient.Create(nil);
IPRegex:=TRegExpr.Create;
try
//returns something like:
{
<html><head><title>Current IP Check</title></head><body>Current IP Address: 44.151.191.44</body></html>
}
RawData:=HTTPClient.Get('http://checkip.dyndns.org');
// adjust for expected output; we just capture the first IP address now:
IPRegex.Expression:=RegExprString('\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b');
//or
//\b(?:\d{1,3}\.){3}\d{1,3}\b
if IPRegex.Exec(RawData) then
begin
result:=IPRegex.Match[0];
end
else
begin
result:='Got invalid results getting external IP address. Details:'+LineEnding+
RawData;
end;
except
on E: Exception do
begin
result:='Error retrieving external IP address: '+E.Message;
end;
end;
finally
HTTPClient.Free;
IPRegex.Free;
end;
end;
begin
writeln('External IP address:');
writeln(GetExternalIPAddress);
end.