assgn6/filewatch.c

   1 #include <unistd.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4
   5 #include <dirent.h>
   6 #include <errno.h>
   7
   8 #include <bsd/string.h>
   9 #include <sys/stat.h>
  10 #include <sys/inotify.h>
  11
  12 int main(int argc, char *argv[]) {
  13
  14     char *lex_path, *u_inp, *ful_p, *ev_buf, *parse_buf;
  15     DIR  *path;
  16     struct dirent *dent;
  17         struct inotify_event *event;
  18         int inotify_fd, watch_fd, rbts;
  19
  20     extern int errno;
  21
  22         lex_path = (char *) calloc(1, NAME_MAX + 1);
  23
  24     if(argc == 1)
  25         lex_path = "./";
  26
  27     else if(argc == 2)
  28         strlcpy(lex_path, argv[1], NAME_MAX + 1);
  29
  30     else {
  31
  32         printf("inappropriate number of args.\n");
  33         return 1;
  34     }
  35
  36     if(!(path = opendir(lex_path))) {
  37
  38         if(errno == EACCES)
  39             printf("improper permissions to read dir.\n");
  40
  41         else if(errno == ENOENT)
  42             printf("given directory does not exist.\n");
  43
  44         else if(errno == ENFILE)
  45             printf("we're out of fd's.\n");
  46
  47         else if(errno == ENOTDIR)
  48             printf("argument is not a directory.\n");
  49
  50         else
  51             printf("an unspecified error occurred.\n");
  52
  53         return errno;
  54     }
  55
  56         u_inp = (char *) calloc(1, NAME_MAX);
  57         ful_p = (char *) calloc(1, 8192); /* PATH_MAX workaround */
  58
  59         while(dent)
  60             if((dent = readdir(path)) != NULL)
  61                         printf("%s\n", dent->d_name);
  62
  63         closedir(path);
  64
  65         printf("file to watch :: ");
  66
  67         fgets(u_inp, NAME_MAX, stdin);
  68         strtok(u_inp, "\n"); /* trim newline */
  69
  70         strlcat(ful_p, lex_path, 8192);
  71         strlcat(ful_p, "/", NAME_MAX + 1);
  72         strlcat(ful_p, u_inp, 8192);
  73
  74         if(!(inotify_fd = inotify_init())) {
  75
  76                 printf("could not access inotify api\n");
  77                 exit(1);
  78         }
  79
  80         if((watch_fd = inotify_add_watch(inotify_fd, ful_p, IN_ACCESS | IN_MODIFY)) == -1) {
  81
  82                 printf("could not open watch on provided file\n");
  83                 exit(1);
  84         }
  85
  86         ev_buf    = (char *) calloc(1, 8192);
  87         parse_buf = (char *) calloc(1, 8192);
  88
  89         for(;;) {
  90
  91                 rbts = read(inotify_fd, ev_buf, 8192);
  92
  93                 for(parse_buf = ev_buf; parse_buf < ev_buf + rbts;) {
  94
  95                         event = (struct inotify_event*) ev_buf;
  96
  97                         if(event->mask == 0x1)
  98                                 printf("file was read\n");
  99                         else
 100                                 printf("file was written\n");
 101
 102                         parse_buf += sizeof(struct inotify_event) + event-> len;
 103                 }
 104         }
 105
 106         free(u_inp);
 107         free(ful_p);
 108         free(lex_path);
 109         free(ev_buf);
 110         free(parse_buf);
 111
 112     return 0;
 113 }