pop.c

/**
 * NOTE:
 *   The shell script at the bottom of the page is
 *   more reliable and less buggy. Go use that instead.
 *
 * Usage: pop [path to cd-drive]
 * Compile: gcc pop.c -o pop
 */

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

#include <fcntl.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <linux/cdrom.h>

int cdrom;

void sigint(int signal) {
    close(cdrom);
    exit(0);
}

int main(int argc, char **argv) {
    const char *path;

    signal(SIGINT, sigint);

    path = (argc >= 2 ? argv[1] : "/dev/sr0");

    if ((cdrom = open(path, O_RDONLY | O_NONBLOCK)) < 0) {
        printf("Unable to open device: %s\n", path);
        return 1;
    } else {
        printf("Watching device: %s\n", path);
    }

    while (1) {
        if (ioctl(cdrom, CDROM_DRIVE_STATUS) != CDS_TRAY_OPEN) {
            puts("pop");
            ioctl(cdrom, CDROMEJECT);
        }
        usleep(500000);
    }

    close(cdrom);
    return 0;
}

pop.sh

#!/bin/sh
################################################################################
# pop.sh
#
# The eject command only ejects if the tray is closed, so we don't need to
# worry about checking the tray status.
#
# Run: ./pop.sh & exit
################################################################################

while true; do
    eject
    sleep 0.5
done