commands/ramdisk/ramdisk.c

   1
   2 #include <paths.h>
   3
   4 #include <sys/ioc_memory.h>
   5 #include <stdio.h>
   6 #include <fcntl.h>
   7 #include <stdlib.h>
   8
   9 int
  10 main(int argc, char *argv[])
  11 {
  12         int fd;
  13         signed long size;
  14         char *d;
  15
  16         if(argc < 2 || argc > 3) {
  17                 fprintf(stderr, "usage: %s <size in kB> [device]\n",
  18                         argv[0]);
  19                 return 1;
  20         }
  21
  22         d = argc == 2 ? _PATH_RAMDISK : argv[2];
  23         if((fd=open(d, O_RDONLY)) < 0) {
  24                 perror(d);
  25                 return 1;
  26         }
  27
  28 #define KFACTOR 1024
  29         size = atol(argv[1])*KFACTOR;
  30
  31         if(size < 0) {
  32                 fprintf(stderr, "size should be non-negative.\n");
  33                 return 1;
  34         }
  35
  36         if(ioctl(fd, MIOCRAMSIZE, &size) < 0) {
  37                 perror("MIOCRAMSIZE");
  38                 return 1;
  39         }
  40
  41         fprintf(stderr, "size on %s set to %ldkB\n", d, size/KFACTOR);
  42
  43         return 0;
  44 }
  45