xmlwf/unixfilemap.c

   1 /* Copyright (c) 1998, 1999 Thai Open Source Software Center Ltd
   2    See the file COPYING for copying permission.
   3 */
   4
   5 #include <sys/types.h>
   6 #include <sys/mman.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <errno.h>
  10 #include <string.h>
  11 #include <stdio.h>
  12 #include <unistd.h>
  13
  14 #ifndef MAP_FILE
  15 #define MAP_FILE 0
  16 #endif
  17
  18 #include "filemap.h"
  19
  20 int
  21 filemap(const char *name,
  22         void (*processor)(const void *, size_t, const char *, void *arg),
  23         void *arg)
  24 {
  25   int fd;
  26   size_t nbytes;
  27   struct stat sb;
  28   void *p;
  29
  30   fd = open(name, O_RDONLY);
  31   if (fd < 0) {
  32     perror(name);
  33     return 0;
  34   }
  35   if (fstat(fd, &sb) < 0) {
  36     perror(name);
  37     close(fd);
  38     return 0;
  39   }
  40   if (!S_ISREG(sb.st_mode)) {
  41     close(fd);
  42     fprintf(stderr, "%s: not a regular file\n", name);
  43     return 0;
  44   }
  45
  46   nbytes = sb.st_size;
  47   /* mmap fails for zero length files */
  48   if (nbytes == 0) {
  49     static const char c = '\0';
  50     processor(&c, 0, name, arg);
  51     close(fd);
  52     return 1;
  53   }
  54   p = (void *)mmap((caddr_t)0, (size_t)nbytes, PROT_READ,
  55                    MAP_FILE|MAP_PRIVATE, fd, (off_t)0);
  56   if (p == (void *)-1) {
  57     perror(name);
  58     close(fd);
  59     return 0;
  60   }
  61   processor(p, nbytes, name, arg);
  62   munmap((caddr_t)p, nbytes);
  63   close(fd);
  64   return 1;
  65 }