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glibc  2.9
Defines | Functions
readdir.c File Reference
#include <errno.h>
#include <stddef.h>
#include <dirent.h>
#include <unistd.h>
#include <endian.h>
#include <assert.h>

Go to the source code of this file.


#define MATCH(memb)


struct dirent__readdir (DIR *dirp)

Define Documentation

#define MATCH (   memb)
assert (offsetof (struct dirent64, memb) - sizeof (entry64->d_ino)          \
         == offsetof (struct dirent, memb) - sizeof (ino_t))

Function Documentation

struct dirent* __readdir ( DIR *  dirp) [read]

Definition at line 28 of file readdir.c.

  struct dirent64 *entry64 = __readdir64 (dirp);

  if (sizeof (struct dirent64) == sizeof (struct dirent))
    /* We should in fact just be an alias to readdir64 on this machine.  */
    return (struct dirent *) entry64;

  /* These are all compile-time constants.  We know that d_ino is the first
     member and that the layout of the following members matches exactly in
     both structures.  */
  assert (offsetof (struct dirent, d_ino) == 0);
  assert (offsetof (struct dirent64, d_ino) == 0);
# define MATCH(memb)                                                 \
  assert (offsetof (struct dirent64, memb) - sizeof (entry64->d_ino)        \
         == offsetof (struct dirent, memb) - sizeof (ino_t))
  MATCH (d_reclen);
  MATCH (d_type);
  MATCH (d_namlen);
# undef MATCH

  if (entry64 == NULL)
    return NULL;

  struct dirent *const entry = ((void *) (&entry64->d_ino + 1)
                            - sizeof entry->d_ino);
  const ino_t d_ino = entry64->d_ino;
  if (d_ino != entry64->d_ino)
      __set_errno (EOVERFLOW);
      return NULL;
# if BYTE_ORDER != BIG_ENDIAN      /* We just skipped over the zero high word.  */
  entry->d_ino = d_ino;     /* ... or the nonzero low word, swap it.  */
# endif
  entry->d_reclen -= sizeof entry64->d_ino - sizeof entry->d_ino;
  return entry;