how can Iconnect a Postgres database using odbc in c language?

I know the following java instructions for connecting a DB (oracle in
this case):

import java.sql......

try {
     Class.forName("oracle.jdbc.driver.OracleDriver");
     String dbUrl ="jdbc:oracle:thin:@"+host+":"+port+":"+sid;
     Connection m_connection =
DriverManager.getConnection(dbUrl,user,passwd);
     Statement m_statement = m_connection.createStatement();
    }
catch (ClassNotFoundException ex) {}

I'd like to know the equivalent instructions in C language using ODBC
for connecting a Postgres DB (with also includes library)

Please, is there anyone can tell me which these C language
instructions are?

Thanks and bye,
Maus