Provided by: manpages-dev_6.03-2_all bug


       stat, fstat, lstat, fstatat - get file status


       Standard C library (libc, -lc)


       #include <sys/stat.h>

       int stat(const char *restrict pathname,
                struct stat *restrict statbuf);
       int fstat(int fd, struct stat *statbuf);
       int lstat(const char *restrict pathname,
                struct stat *restrict statbuf);

       #include <fcntl.h>           /* Definition of AT_* constants */
       #include <sys/stat.h>

       int fstatat(int dirfd, const char *restrict pathname,
                struct stat *restrict statbuf, int flags);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

           /* Since glibc 2.20 */ _DEFAULT_SOURCE
               || _XOPEN_SOURCE >= 500
               || /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200112L
               || /* glibc 2.19 and earlier */ _BSD_SOURCE

           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:


       These  functions return information about a file, in the buffer pointed to by statbuf.  No
       permissions are required on the file itself, but—in the case  of  stat(),  fstatat(),  and
       lstat()—execute (search) permission is required on all of the directories in pathname that
       lead to the file.

       stat() and fstatat() retrieve information about the  file  pointed  to  by  pathname;  the
       differences for fstatat() are described below.

       lstat()  is  identical  to  stat(),  except  that  if pathname is a symbolic link, then it
       returns information about the link itself, not the file that the link refers to.

       fstat() is identical to stat(), except that the file about  which  information  is  to  be
       retrieved is specified by the file descriptor fd.

   The stat structure
       All of these system calls return a stat structure (see stat(3type)).

       Note:  for  performance and simplicity reasons, different fields in the stat structure may
       contain state information from different moments during the execution of the system  call.
       For  example,  if  st_mode  or st_uid is changed by another process by calling chmod(2) or
       chown(2), stat() might return the old st_mode together with the new  st_uid,  or  the  old
       st_uid together with the new st_mode.

       The fstatat() system call is a more general interface for accessing file information which
       can still provide exactly the behavior of each of stat(), lstat(), and fstat().

       If the pathname given in pathname is relative, then it  is  interpreted  relative  to  the
       directory  referred  to  by the file descriptor dirfd (rather than relative to the current
       working directory of the calling process, as is done by stat() and lstat() for a  relative

       If  pathname  is  relative  and  dirfd  is  the  special  value AT_FDCWD, then pathname is
       interpreted relative to the current working directory of the calling process (like  stat()
       and lstat()).

       If pathname is absolute, then dirfd is ignored.

       flags can either be 0, or include one or more of the following flags ORed:

       AT_EMPTY_PATH (since Linux 2.6.39)
              If pathname is an empty string, operate on the file referred to by dirfd (which may
              have been obtained using the open(2) O_PATH flag).  In this case, dirfd  can  refer
              to any type of file, not just a directory, and the behavior of fstatat() is similar
              to that of fstat().  If dirfd is AT_FDCWD, the call operates on the current working
              directory.    This  flag  is  Linux-specific;  define  _GNU_SOURCE  to  obtain  its

       AT_NO_AUTOMOUNT (since Linux 2.6.38)
              Don't automount the terminal ("basename") component of pathname.  Since  Linux  3.1
              this flag is ignored.  Since Linux 4.11 this flag is implied.

              If  pathname  is a symbolic link, do not dereference it: instead return information
              about the link itself, like lstat().  (By default, fstatat() dereferences  symbolic
              links, like stat().)

       See openat(2) for an explanation of the need for fstatat().


       On  success, zero is returned.  On error, -1 is returned, and errno is set to indicate the


       EACCES Search permission is denied for one of  the  directories  in  the  path  prefix  of
              pathname.  (See also path_resolution(7).)

       EBADF  fd is not a valid open file descriptor.

       EBADF  (fstatat())  pathname  is  relative  but dirfd is neither AT_FDCWD nor a valid file

       EFAULT Bad address.

       EINVAL (fstatat()) Invalid flag specified in flags.

       ELOOP  Too many symbolic links encountered while traversing the path.

              pathname is too long.

       ENOENT A component of pathname does not exist or is a dangling symbolic link.

       ENOENT pathname is an empty string and AT_EMPTY_PATH was not specified in flags.

       ENOMEM Out of memory (i.e., kernel memory).

              A component of the path prefix of pathname is not a directory.

              (fstatat()) pathname is relative and dirfd is a file descriptor referring to a file
              other than a directory.

              pathname  or  fd  refers  to  a  file whose size, inode number, or number of blocks
              cannot be represented in, respectively, the types off_t, ino_t, or blkcnt_t.   This
              error  can  occur  when,  for example, an application compiled on a 32-bit platform
              without -D_FILE_OFFSET_BITS=64 calls stat() on a file whose size exceeds  (1<<31)-1


       fstatat() was added in Linux 2.6.16; library support was added in glibc 2.4.


       stat(), fstat(), lstat(): SVr4, 4.3BSD, POSIX.1-2001, POSIX.1.2008.

       fstatat(): POSIX.1-2008.

       According  to  POSIX.1-2001, lstat() on a symbolic link need return valid information only
       in the st_size field and the file type  of  the  st_mode  field  of  the  stat  structure.
       POSIX.1-2008  tightens the specification, requiring lstat() to return valid information in
       all fields except the mode bits in st_mode.

       Use of the st_blocks and st_blksize fields may be less portable.  (They were introduced in
       BSD.  The interpretation differs between systems, and possibly on a single system when NFS
       mounts are involved.)


   C library/kernel differences
       Over time, increases in the size of the  stat  structure  have  led  to  three  successive
       versions  of  stat():  sys_stat() (slot __NR_oldstat), sys_newstat() (slot __NR_stat), and
       sys_stat64() (slot __NR_stat64) on 32-bit platforms such as i386.  The first two  versions
       were  already  present  in  Linux 1.0 (albeit with different names); the last was added in
       Linux 2.4.  Similar remarks apply for fstat() and lstat().

       The kernel-internal versions of the stat structure dealt with by  the  different  versions
       are, respectively:

              The original structure, with rather narrow fields, and no padding.

       stat   Larger  st_ino  field  and padding added to various parts of the structure to allow
              for future expansion.

       stat64 Even larger st_ino field, larger  st_uid  and  st_gid  fields  to  accommodate  the
              Linux-2.4  expansion of UIDs and GIDs to 32 bits, and various other enlarged fields
              and further padding in the  structure.   (Various  padding  bytes  were  eventually
              consumed  in  Linux  2.6,  with  the  advent  of  32-bit  device IDs and nanosecond
              components for the timestamp fields.)

       The glibc stat() wrapper function hides these details from applications, invoking the most
       recent  version  of  the  system  call  provided by the kernel, and repacking the returned
       information if required for old binaries.

       On modern 64-bit systems, life is simpler: there is a single stat() system  call  and  the
       kernel deals with a stat structure that contains fields of a sufficient size.

       The  underlying  system  call employed by the glibc fstatat() wrapper function is actually
       called fstatat64() or, on some architectures, newfstatat().


       The following program calls lstat() and displays selected  fields  in  the  returned  stat

       #include <stdint.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <sys/stat.h>
       #include <sys/sysmacros.h>
       #include <time.h>

       main(int argc, char *argv[])
           struct stat sb;

           if (argc != 2) {
               fprintf(stderr, "Usage: %s <pathname>\n", argv[0]);

           if (lstat(argv[1], &sb) == -1) {

           printf("ID of containing device:  [%x,%x]\n",

           printf("File type:                ");

           switch (sb.st_mode & S_IFMT) {
           case S_IFBLK:  printf("block device\n");            break;
           case S_IFCHR:  printf("character device\n");        break;
           case S_IFDIR:  printf("directory\n");               break;
           case S_IFIFO:  printf("FIFO/pipe\n");               break;
           case S_IFLNK:  printf("symlink\n");                 break;
           case S_IFREG:  printf("regular file\n");            break;
           case S_IFSOCK: printf("socket\n");                  break;
           default:       printf("unknown?\n");                break;

           printf("I-node number:            %ju\n", (uintmax_t) sb.st_ino);

           printf("Mode:                     %jo (octal)\n",
                  (uintmax_t) sb.st_mode);

           printf("Link count:               %ju\n", (uintmax_t) sb.st_nlink);
           printf("Ownership:                UID=%ju   GID=%ju\n",
                  (uintmax_t) sb.st_uid, (uintmax_t) sb.st_gid);

           printf("Preferred I/O block size: %jd bytes\n",
                  (intmax_t) sb.st_blksize);
           printf("File size:                %jd bytes\n",
                  (intmax_t) sb.st_size);
           printf("Blocks allocated:         %jd\n",
                  (intmax_t) sb.st_blocks);

           printf("Last status change:       %s", ctime(&sb.st_ctime));
           printf("Last file access:         %s", ctime(&sb.st_atime));
           printf("Last file modification:   %s", ctime(&sb.st_mtime));



       ls(1),   stat(1),   access(2),   chmod(2),   chown(2),  readlink(2),  statx(2),  utime(2),
       stat(3type), capabilities(7), inode(7), symlink(7)