part-delete.c

/*BINFMTC: -Wall
 */

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <strings.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/fs.h>
#include <linux/blkpg.h>

int main(int argc, char **argv) {
  if (argc != 2) {
    fprintf(stderr, "Usage: %s /dev/someblk\n", argv[0]);
    return 0;
  }
  char *dev = argv[1];

  int fd = open(dev, O_RDWR);

  ioctl(fd, BLKFLSBUF);

  struct blkpg_ioctl_arg arg;
  struct blkpg_partition pinfo = {0};

  for (int pno = 1; pno < 100; pno++) {
    pinfo.pno = pno;
    sprintf(pinfo.devname, "%sp%d", rindex(dev, '/') + 1, pno);

    arg.op      = BLKPG_DEL_PARTITION;
    arg.flags   = 0;
    arg.datalen = sizeof(pinfo);
    arg.data    = &pinfo;

    ioctl(fd, BLKPG, &arg);
  }

  close(fd);
}