//+------------------------------------------------------------------+
//| SocketIsWritable.mq5 |
//| Copyright 2024, MetaQuotes Ltd. |
//| https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2024, MetaQuotes Ltd."
#property link "https://www.mql5.com
#property version "1.00"
#property description "Add Address to the list of allowed ones in the terminal settings to let the example work"
#property script_show_inputs
input string Address ="www.mql5.com";
input int Port =80;
bool ExtTLS =false;
//+------------------------------------------------------------------+
//| Script program start function |
//+------------------------------------------------------------------+
void OnStart(void)
{
//--- create a socket and get its handle
int socket=SocketCreate();
//--- check the handle
if(socket!=INVALID_HANDLE)
{
//--- if all is well, connect
if(SocketConnect(socket,Address,Port,1000))
{
PrintFormat("Established connection to %s:%d",Address,Port);
string subject,issuer,serial,thumbprint;
datetime expiration;
//--- if connection is protected by certificate, display its data
if(SocketTlsCertificate(socket,subject,issuer,serial,thumbprint,expiration))
{
Print("TLS certificate:");
Print(" Owner: ",subject);
Print(" Issuer: ",issuer);
Print(" Number: ",serial);
Print(" Print: ",thumbprint);
Print(" Expiration: ",expiration);
ExtTLS=true;
}
//--- send GET request to the server
if(HTTPSend(socket,"GET / HTTP/1.1\r\nHost: www.mql5.com\r\nUser-Agent: MT5\r\n\r\n"))
{
Print("GET request sent");
//--- read response
if(!HTTPRecv(socket,1000))
Print("Failed to get a response, error ",GetLastError());
}
else
Print("Failed to send GET request, error ",GetLastError());
}
else
{
PrintFormat("Connection to %s:%d failed, error %d",Address,Port,GetLastError());
}
//--- display the ability to write data to the socket at the current moment in time in the journal
if(SocketIsWritable(socket))
Print("At the current moment in time, writing data to the socket is possible");
else
Print("It is not possible to write data to the socket at the current time");
//--- close the socket after use
if(SocketClose(socket))
Print("Now the socket is closed");
}
else
Print("Failed to create a socket, error ",GetLastError());
/*
result:
At the current moment in time, writing data to the socket is possible
Socket is closed now
*/
}
//+------------------------------------------------------------------+
//| Send command to server |
//+------------------------------------------------------------------+
bool HTTPSend(int socket,string request)
{
//--- convert the string to a character array, discard the terminating zero
char req[];
int len=StringToCharArray(request,req)-1;
if(len<0)
return(false);
//--- if a secure TLS connection via port 443 is used
if(ExtTLS)
return(SocketTlsSend(socket,req,len)==len);
//--- if a regular TCP connection is used
return(SocketSend(socket,req,len)==len);
}
//+------------------------------------------------------------------+
//| Read server response |
//+------------------------------------------------------------------+
bool HTTPRecv(int socket,uint timeout_ms)
{
char rsp[];
string result;
ulong timeout_check=GetTickCount64()+timeout_ms;
//--- read data from the socket while there is some, but not longer than timeout
do
{
uint len=SocketIsReadable(socket);
if(len)
{
int rsp_len;
//--- different read commands depending on whether the connection is secure or not
if(ExtTLS)
rsp_len=SocketTlsRead(socket,rsp,len);
else
rsp_len=SocketRead(socket,rsp,len,timeout_ms);
//--- parse response
if(rsp_len>0)
{
result+=CharArrayToString(rsp,0,rsp_len);
//--- display response header only
int header_end=StringFind(result,"\r\n\r\n");
if(header_end>0)
{
Print("HTTP answer header received:");
Print(StringSubstr(result,0,header_end));
return(true);
}
//--- update read timeout expiration time
timeout_check=GetTickCount64()+timeout_ms;
}
}
}
while(GetTickCount64()<timeout_check && !IsStopped());
return(false);
}
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