PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

FSTAT(3P)                 POSIX Programmer's Manual                FSTAT(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       fstat — get file status

SYNOPSIS         top

       #include <sys/stat.h>

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

DESCRIPTION         top

       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 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 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.

       For all other file types defined in this volume of POSIX.1‐2008, the
       structure members st_mode, st_ino, st_dev, st_uid, st_gid, st_atim,
       st_ctim, and st_mtim shall have meaningful values and the value of
       the st_nlink member 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 POSIX.1‐2008, Section
       4.8, File Times Update), before writing into the stat structure.

RETURN VALUE         top

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

ERRORS         top

       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         top

   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         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       fstatat(3p)

       The Base Definitions volume of POSIX.1‐2008, Section 4.8, File Times
       Update, sys_stat.h(0p), sys_types.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                           FSTAT(3P)

Pages that refer to this page: sys_stat.h(0p)fstatat(3p)posix_typed_mem_get_info(3p)posix_typed_mem_open(3p)utime(3p)