#include <stdio.h>
#include <stdlib.h>
#include <libpq-fe.h>

int main(int argc, char **argv) {
    // create what we need to connect: the db connection structure and its options
    PGconn *conn;
    const char *dbopts;
    
    // accept an argument on the command line to pass to Postgres
    if (argc > 1) {
        dbopts = argv[1];
    } else {
        dbopts = "dbname = default";
    }

    // 1: attempt to connect
    conn = PQconnectdb(dbopts);
    // 2: check for an OK status that is...
    // 3: wrapped in a code block
    if (PQstatus(conn) != CONNECTION_OK) {
        fprintf(stderr, "Connection failed: %s\n", PQerrorMessage(conn));
    } else {
        // 4: do your business
        printf("Connection successful!\n");
    }
    // 5: close the connection
    PQfinish(conn);
    exit(1);
}