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nagios-plugins  1.4.16
Defines | Functions
open.c File Reference
#include <config.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

Go to the source code of this file.

Defines

#define __need_system_fcntl_h
#define REPLACE_OPEN_DIRECTORY   0

Functions

static int orig_open (const char *filename, int flags, mode_t mode)
int open (const char *filename, int flags,...)

Define Documentation

Definition at line 22 of file open.c.

#define REPLACE_OPEN_DIRECTORY   0

Definition at line 44 of file open.c.


Function Documentation

int open ( const char *  filename,
int  flags,
  ... 
)

Definition at line 48 of file open.c.

{
  mode_t mode;
  int fd;

  mode = 0;
  if (flags & O_CREAT)
    {
      va_list arg;
      va_start (arg, flags);

      /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
         creates crashing code when 'mode_t' is smaller than 'int'.  */
      mode = va_arg (arg, PROMOTED_MODE_T);

      va_end (arg);
    }

#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  if (strcmp (filename, "/dev/null") == 0)
    filename = "NUL";
#endif

#if OPEN_TRAILING_SLASH_BUG
  /* If the filename ends in a slash and one of O_CREAT, O_WRONLY, O_RDWR
     is specified, then fail.
     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
     says that
       "A pathname that contains at least one non-slash character and that
        ends with one or more trailing slashes shall be resolved as if a
        single dot character ( '.' ) were appended to the pathname."
     and
       "The special filename dot shall refer to the directory specified by
        its predecessor."
     If the named file already exists as a directory, then
       - if O_CREAT is specified, open() must fail because of the semantics
         of O_CREAT,
       - if O_WRONLY or O_RDWR is specified, open() must fail because POSIX
         <http://www.opengroup.org/susv3/functions/open.html> says that it
         fails with errno = EISDIR in this case.
     If the named file does not exist or does not name a directory, then
       - if O_CREAT is specified, open() must fail since open() cannot create
         directories,
       - if O_WRONLY or O_RDWR is specified, open() must fail because the
         file does not contain a '.' directory.  */
  if (flags & (O_CREAT | O_WRONLY | O_RDWR))
    {
      size_t len = strlen (filename);
      if (len > 0 && filename[len - 1] == '/')
        {
          errno = EISDIR;
          return -1;
        }
    }
#endif

  fd = orig_open (filename, flags, mode);

#if REPLACE_FCHDIR
  /* Implementing fchdir and fdopendir requires the ability to open a
     directory file descriptor.  If open doesn't support that (as on
     mingw), we use a dummy file that behaves the same as directories
     on Linux (ie. always reports EOF on attempts to read()), and
     override fstat() in fchdir.c to hide the fact that we have a
     dummy.  */
  if (REPLACE_OPEN_DIRECTORY && fd < 0 && errno == EACCES
      && (flags & O_ACCMODE) == O_RDONLY)
    {
      struct stat statbuf;
      if (stat (filename, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
        {
          /* Maximum recursion depth of 1.  */
          fd = open ("/dev/null", flags, mode);
          if (0 <= fd)
            fd = _gl_register_fd (fd, filename);
        }
      else
        errno = EACCES;
    }
#endif

#if OPEN_TRAILING_SLASH_BUG
  /* If the filename ends in a slash and fd does not refer to a directory,
     then fail.
     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
     says that
       "A pathname that contains at least one non-slash character and that
        ends with one or more trailing slashes shall be resolved as if a
        single dot character ( '.' ) were appended to the pathname."
     and
       "The special filename dot shall refer to the directory specified by
        its predecessor."
     If the named file without the slash is not a directory, open() must fail
     with ENOTDIR.  */
  if (fd >= 0)
    {
      /* We know len is positive, since open did not fail with ENOENT.  */
      size_t len = strlen (filename);
      if (filename[len - 1] == '/')
        {
          struct stat statbuf;

          if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
            {
              close (fd);
              errno = ENOTDIR;
              return -1;
            }
        }
    }
#endif

#if REPLACE_FCHDIR
  if (!REPLACE_OPEN_DIRECTORY && 0 <= fd)
    fd = _gl_register_fd (fd, filename);
#endif

  return fd;
}

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static int orig_open ( const char *  filename,
int  flags,
mode_t  mode 
) [inline, static]

Definition at line 28 of file open.c.

{
  return open (filename, flags, mode);
}

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