i386/ucla/src/lab5/user/ls.c

   1 #include <inc/lib.h>
   2
   3 int flag[256];
   4
   5 void lsdir(const char*, const char*);
   6 void ls1(const char*, bool, off_t, const char*);
   7
   8 void
   9 ls(const char *path, const char *prefix)
  10 {
  11         int r;
  12         struct Stat st;
  13
  14         if ((r = stat(path, &st)) < 0)
  15                 panic("stat %s: %e", path, r);
  16         if (st.st_ftype == FTYPE_DIR && !flag[(int) 'd'])
  17                 lsdir(path, prefix);
  18         else
  19                 ls1(0, st.st_ftype == FTYPE_DIR, st.st_size, path);
  20 }
  21
  22 void
  23 lsdir(const char *path, const char *prefix)
  24 {
  25         int fd, n;
  26         char name[MAXNAMELEN];
  27         struct Direntry de;
  28         struct Stat st;
  29
  30         if ((fd = open(path, O_RDONLY)) < 0)
  31                 panic("open %s: %e", path, fd);
  32         while ((n = readn(fd, &de, sizeof de)) == sizeof de)
  33                 if (de.de_inum) {
  34                         memcpy(name, de.de_name, MAXNAMELEN);
  35                         name[de.de_namelen] = 0;
  36                         istat(de.de_inum, &st);
  37                         ls1(prefix, st.st_ftype==FTYPE_DIR, st.st_size, name);
  38                 }
  39         if (n > 0)
  40                 panic("short read in directory %s", path);
  41         if (n < 0)
  42                 panic("error reading directory %s: %e", path, n);
  43 }
  44
  45 void
  46 ls1(const char *prefix, bool isdir, off_t size, const char *name)
  47 {
  48         const char *sep;
  49
  50         if (flag[(int) 'l'])
  51                 fprintf(1, "%11d %c ", size, isdir ? 'd' : '-');
  52         if (prefix) {
  53                 if (prefix[0] && prefix[strlen(prefix)-1] != '/')
  54                         sep = "/";
  55                 else
  56                         sep = "";
  57                 fprintf(1, "%s%s", prefix, sep);
  58         }
  59         fprintf(1, "%s", name);
  60         if (flag[(int) 'F'] && isdir)
  61                 fprintf(1, "/");
  62         fprintf(1, "\n");
  63 }
  64
  65 void
  66 usage(void)
  67 {
  68         fprintf(1, "usage: ls [-dFl] [file...]\n");
  69         exit();
  70 }
  71
  72 asmlinkage void
  73 umain(int argc, char **argv)
  74 {
  75         int i;
  76         struct Argstate args;
  77
  78         argstart(&argc, argv, &args);
  79         while ((i = argnext(&args)) >= 0)
  80                 switch (i) {
  81                 case 'd':
  82                 case 'F':
  83                 case 'l':
  84                         flag[i]++;
  85                         break;
  86                 default:
  87                         usage();
  88                 }
  89
  90         if (argc == 1)
  91                 ls("/", "");
  92         else {
  93                 for (i = 1; i < argc; i++)
  94                         ls(argv[i], argv[i]);
  95         }
  96 }