sys/src/cmd/swap.c

   1 #include <u.h>
   2 #include <libc.h>
   3
   4 void
   5 main(int argc, char **argv)
   6 {
   7         int swapfd, cswfd;
   8         char buf[1024], *p;
   9         Dir *d;
  10
  11         ARGBEGIN {
  12         } ARGEND;
  13
  14         if(argc != 1){
  15                 fprint(2, "Usage: swap file\n");
  16                 exits("usage");
  17         }
  18
  19         swapfd = -1;
  20         if(d = dirstat(p = *argv)){
  21                 if(d->mode & DMDIR){
  22                         p = getenv("sysname");
  23                         if(p == 0)
  24                                 p = "swap";
  25                         snprint(buf, sizeof buf, "%s/%sXXXXXXX", *argv, p);
  26                         p = mktemp(buf);
  27                 } else
  28                         swapfd = open(p, ORDWR);
  29         }
  30         if(d == nil || (d->mode & DMDIR)){
  31                 if((swapfd = create(p, ORDWR|ORCLOSE, 0600)) >= 0){
  32                         Dir nd;
  33
  34                         nulldir(&nd);
  35                         nd.mode = DMTMP|0600;
  36                         dirfwstat(swapfd, &nd);
  37                 }
  38         }
  39         if(swapfd < 0)
  40                 sysfatal("%r");
  41         if(fd2path(swapfd, p = buf, sizeof buf))
  42                 sysfatal("fd2path: %r");
  43         if(putenv("swap", p) < 0)
  44                 sysfatal("putenv: %r");
  45
  46         print("swap: %s\n", p);
  47
  48         if((cswfd = open("/dev/swap", OWRITE)) < 0)
  49                 sysfatal("open: %r");
  50         if(fprint(cswfd, "%d", swapfd) < 0)
  51                 sysfatal("write: %r");
  52
  53         exits(0);
  54 }