UNIX 6th Ed. - /usr/source/s1/df.c

   1: char    *dargv[]
   2: {
   3:     0,
   4:     "/dev/rk2",
   5:     "/dev/rp0",
   6:     0
   7: };
   8: struct
   9: {
  10:     char    *s_isize;
  11:     char    *s_fsize;
  12:     int s_nfree;
  13:     int s_free[100];
  14:     int s_ninode;
  15:     int s_inode[100];
  16:     char    s_flock;
  17:     char    s_ilock;
  18:     char    s_fmod;
  19:     int time[2];
  20:     int pad[50];
  21: } sblock;
  22: 
  23: int fi;
  24: 
  25: main(argc, argv)
  26: char **argv;
  27: {
  28:     int i;
  29: 
  30:     if(argc <= 1) {
  31:         for(argc = 1; dargv[argc]; argc++);
  32:         argv = dargv;
  33:     }
  34: 
  35:     for(i=1; i<argc; i++) {
  36:         if(argc > 1)
  37:             printf("%s ", argv[i]);
  38:         dfree(argv[i]);
  39:     }
  40: }
  41: 
  42: dfree(file)
  43: char *file;
  44: {
  45:     int i;
  46: 
  47:     fi = open(file, 0);
  48:     if(fi < 0) {
  49:         printf("cannot open %s\n", file);
  50:         return;
  51:     }
  52:     sync();
  53:     bread(1, &sblock);
  54:     i = 0;
  55:     while(alloc())
  56:         i++;
  57:     printf("%l\n", i);
  58:     close(fi);
  59: }
  60: 
  61: alloc()
  62: {
  63:     int b, i, buf[256];
  64: 
  65:     i = --sblock.s_nfree;
  66:     if(i<0 || i>=100) {
  67:         printf("bad free count\n");
  68:         return(0);
  69:     }
  70:     b = sblock.s_free[i];
  71:     if(b == 0)
  72:         return(0);
  73:     if(b<sblock.s_isize+2 || b>=sblock.s_fsize) {
  74:         printf("bad free block (%l)\n", b);
  75:         return(0);
  76:     }
  77:     if(sblock.s_nfree <= 0) {
  78:         bread(b, buf);
  79:         sblock.s_nfree = buf[0];
  80:         for(i=0; i<100; i++)
  81:             sblock.s_free[i] = buf[i+1];
  82:     }
  83:     return(b);
  84: }
  85: 
  86: bread(bno, buf)
  87: {
  88:     int n;
  89:     extern errno;
  90: 
  91:     seek(fi, bno, 3);
  92:     if((n=read(fi, buf, 512)) != 512) {
  93:         printf("read error %d\n", bno);
  94:         printf("count = %d; errno = %d\n", n, errno);
  95:         exit();
  96:     }
  97: }

Defined functions

Defined variables