output.c

#include "sysfs-gpio.h"
#include <stdio.h>
// #include <unistd.h>

int main()
{
        struct Gpio gpio = GPIO_INITIALIZER;
        gpio_open_output( &gpio, "/dev/gpio/relay-jp3", "low" );

        gpio_open( &gpio, "/dev/gpio/relay-jp3", "low" );
        if( gpio_is_output( &gpio ) ) {
                gpio_write( &gpio, 0 );
        } else {
                gpio_set_direction_output( &gpio, "high" );
        }
        gpio_set_direction_output(&gpio, "low");
        int const timeout_ms = 3000;  // -1 = no timeout

        printf( "Print in %d milliseconds.\n ", timeout_ms );
        gpio_close( &gpio );
        return 0;
}