systemd-active-user.c

/* gcc `pkg-config --cflags --libs libsystemd-login` systemd-active-user.c -o systemd-active-user
 * get current active user id that has process in 'foreground' according to documentation */

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    uid_t *uids = NULL, uactiveid = 0;
    int i, num = sd_get_uids(&uids);
    for (i = 0; i < num; ++i) {
        char *state = NULL;
        sd_uid_get_state(uids[i], &state);
        if (!strcmp(state, "active")) uactiveid = uids[i];
        if (state) free(state);
    }
    if (uids) free(uids);
    printf("%u\n", uactiveid);
    return EXIT_SUCCESS;
}

/* vim: set ts=8 sw=4 tw=0 :*/