NAME

       fstat - get file status

SYNOPSIS

       #include <sys/stat.h>

       int fstat(int fildes, struct stat *buf);

DESCRIPTION

       The  fstat()  function  shall  obtain  information about an open file associated with the file descriptor
       fildes, and shall write it to the area pointed to by buf.

       If fildes references a shared memory object, the  implementation  shall  update  in  the  stat  structure
       pointed  to  by  the  buf  argument  only  the  st_uid, st_gid, st_size, and st_mode fields, and only the
       S_IRUSR, S_IWUSR, S_IRGRP, S_IWGRP, S_IROTH,  and  S_IWOTH  file  permission  bits  need  be  valid.  The
       implementation may update other fields and flags.

       If fildes references a typed memory object, the implementation shall update in the stat structure pointed
       to  by  the  buf  argument  only  the  st_uid, st_gid, st_size, and st_mode fields, and only the S_IRUSR,
       S_IWUSR, S_IRGRP, S_IWGRP, S_IROTH, and S_IWOTH file permission bits need be  valid.  The  implementation
       may update other fields and flags.

       The  buf argument is a pointer to a stat structure, as defined in <sys/stat.h>, into which information is
       placed concerning the file.

       The structure members st_mode, st_ino, st_dev, st_uid, st_gid, st_atime,  st_ctime,  and  st_mtime  shall
       have meaningful values for all other file types defined in this volume of IEEE Std 1003.1-2001. The value
       of the member st_nlink shall be set to the number of links to the file.

       An  implementation  that  provides  additional  or  alternative file access control mechanisms may, under
       implementation-defined conditions, cause fstat() to fail.

       The fstat() function shall update any time-related fields as described in the Base Definitions volume  of
       IEEE Std 1003.1-2001, Section 4.7, File Times Update, before writing into the stat structure.

RETURN VALUE

       Upon  successful  completion,  0  shall  be  returned.  Otherwise,  -1 shall be returned and errno set to
       indicate the error.

ERRORS

       The fstat() function shall fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       EIO    An I/O error occurred while reading from the file system.

       EOVERFLOW
              The file size in bytes or the number of blocks allocated to the file or  the  file  serial  number
              cannot be represented correctly in the structure pointed to by buf.

       The fstat() function may fail if:

       EOVERFLOW
              One of the values is too large to store into the structure pointed to by the buf argument.

       The following sections are informative.

EXAMPLES

   Obtaining File Status Information
       The  following  example  shows how to obtain file status information for a file named /home/cnd/mod1. The
       structure variable buffer is defined for the stat structure.  The  /home/cnd/mod1  file  is  opened  with
       read/write privileges and is passed to the open file descriptor fildes.

              #include <sys/types.h>
              #include <sys/stat.h>
              #include <fcntl.h>

              struct stat buffer;
              int         status;
              ...
              fildes = open("/home/cnd/mod1", O_RDWR);
              status = fstat(fildes, &buffer);

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       lstat() , stat() , the Base Definitions volume of IEEE Std 1003.1-2001, <sys/stat.h>, <sys/types.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc and The Open Group. In the event of any discrepancy between this version and the  original  IEEE  and
       The  Open  Group  Standard,  the  original  IEEE and The Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                                   2003                                              FSTAT(P)