sys/src/cmd/lp/ipcopen.c

   1 #include <u.h>
   2 #include <libc.h>
   3
   4 int ppid;
   5
   6 /*
   7  * predefined
   8  */
   9 void pass(int from, int to);
  10
  11
  12 /*
  13  *  Connect to given datakit port
  14  */
  15 main(int argc, char *argv[])
  16 {
  17         int fd0, fd1;
  18         int cpid;
  19         char c;
  20         char *cp, *devdir, *buf;
  21
  22         if (argc != 4) {
  23                 fprint(2, "usage: %s destination network service\n", argv[0]);
  24                 exits("incorrect number of arguments");
  25         }
  26         if(!(cp = malloc((long)(strlen(argv[1])+strlen(argv[2])+strlen(argv[3])+8)))) {
  27                 perror("malloc");
  28                 exits("malloc failed");
  29         }
  30         sprint(cp, "%s!%s!%s", argv[2], argv[1], argv[3]);
  31         if (dial(cp, &devdir, 0) < 0) {
  32                 fprint(2, "dialing %s\n", cp);
  33                 perror("dial");
  34                 exits("can't dial");
  35         }
  36
  37         /*
  38          * Initialize the input fd, and copy bytes.
  39          */
  40
  41         if(!(buf = malloc((long)(strlen(devdir)+6)))) {
  42                 perror("malloc");
  43                 exits("malloc failed");
  44         }
  45         sprint(buf, "%s/data", devdir);
  46         fd0=open(buf, OREAD);
  47         fd1=open(buf, OWRITE);
  48         if(fd0<0 || fd1<0) {
  49                 print("can't open", buf);
  50                 exits("can't open port");
  51         }
  52         ppid = getpid();
  53         switch(cpid = fork()){
  54         case -1:
  55                 perror("fork failed");
  56                 exits("fork failed");
  57         case 0:
  58                 close(0);
  59                 close(fd1);
  60                 pass(fd0, 1);   /* from remote */
  61                 hangup(fd0);
  62                 close(1);
  63                 close(fd0);
  64                 exits("");
  65         default:
  66                 close(1);
  67                 close(fd0);
  68                 pass(0, fd1);   /* to remote */
  69                 hangup(fd1);
  70                 close(0);
  71                 close(fd1);
  72                 exits("");
  73         }
  74 }
  75
  76 void
  77 pass(int from, int to)
  78 {
  79         char buf[1024];
  80         int ppid, cpid;
  81         int n, tot = 0;
  82
  83         while ((n=read(from, buf, sizeof(buf))) > 0) {
  84                 if (n==1 && tot==0 && *buf=='\0')
  85                         break;
  86                 tot += n;
  87                 if (write(to, buf, n)!=n) {
  88                         perror("pass write error");
  89                         exits("pass write error");
  90                 }
  91         }
  92 }