test3.c

#include <stdio.h>
#include <mpd/client.h>

int main(void) {

    struct mpd_connection *mpd;
    struct mpd_song *song;

    mpd = mpd_connection_new("127.0.0.1", 6600, 0);
    if (mpd_connection_get_error(mpd) != MPD_ERROR_SUCCESS)
        return 1;

    if ((song = mpd_run_current_song(mpd)) == NULL)
        return 1;

    puts(mpd_song_get_uri(song));

    mpd_song_free(song);
    mpd_connection_free(mpd);
    return 0;
}