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STAT(2) 		       System Calls Manual			 STAT(2)

NAME
     stat, lstat, fstat, fstatat -- get file status

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/stat.h>

     int
     stat(const char * restrict path, struct stat * restrict sb);

     int
     lstat(const char * restrict path, struct stat * restrict sb);

     int
     fstat(int fd, struct stat *sb);

     int
     fstatat(int fd, const char *path, struct stat *sb, int flag);

DESCRIPTION
     The  stat()  system  call	obtains information about the file pointed to by
     path.  Read, write or execute permission of the named file is not required,
     but all directories listed in the path name leading to  the  file	must  be
     searchable.

     The lstat() system call is like stat() except when the named file is a sym-
     bolic link, in which case lstat() returns information about the link, while
     stat() returns information about the file the link references.

     The  fstat()  system  call  obtains the same information about an open file
     known by the file descriptor fd.

     The fstatat() system call is equivalent to stat() and lstat()  except  when
     the  path	specifies a relative path.  For fstatat() and relative path, the
     status is retrieved from a file relative to the directory	associated  with
     the file descriptor fd instead of the current working directory.

     The  values for the flag are constructed by a bitwise-inclusive OR of flags
     from this list, defined in <fcntl.h>:

     AT_SYMLINK_NOFOLLOW
	     If path names a symbolic link, the status of the symbolic	link  is
	     returned.

     AT_RESOLVE_BENEATH
	     Only  walk paths below the starting directory.  See the description
	     of the O_RESOLVE_BENEATH flag in the open(2) manual page.

     If fstatat() is passed the special value AT_FDCWD in the fd parameter,  the
     current  working  directory is used and the behavior is identical to a call
     to stat()	or  lstat()  respectively,  depending  on  whether  or	not  the
     AT_SYMLINK_NOFOLLOW bit is set in flag.

     When fstatat() is called with an absolute path, it ignores the fd argument.

     The sb argument is a pointer to a stat structure as defined by <sys/stat.h>
     and into which information is placed concerning the file.

     The fields of struct stat related to the file system are:

     st_dev    Numeric ID of the device containing the file.

     st_ino    The file's inode number.

     st_nlink  Number of hard links to the file.

     st_flags  Flags enabled for the file.  See chflags(2) for the list of flags
	       and their description.

     The st_dev and st_ino fields together identify the file uniquely within the
     system.

     The time-related fields of struct stat are:

     st_atim	  Time	when file data was last accessed.  Changed implicitly by
		  syscalls such as  read(2)  and  readv(2),  and  explicitly  by
		  utimes(2).

     st_mtim	  Time	when file data was last modified.  Changed implicitly by
		  syscalls such as truncate(2), write(2), and writev(2), and ex-
		  plicitly by utimes(2).  Also, any syscall which  modifies  di-
		  rectory  content  changes  the st_mtim for the affected direc-
		  tory.  For instance, creat(2), mkdir(2),  rename(2),	link(2),
		  and unlink(2).

     st_ctim	  Time	when  file status was last changed (inode data modifica-
		  tion).  Changed implicitly by any syscall  that  affects  file
		  metadata,  including	st_mtim,  such	as chflags(2), chmod(2),
		  chown(2), truncate(2), utimes(2),  and  write(2).   Also,  any
		  syscall  which  modifies directory content changes the st_ctim
		  for the affected directory.  For instance, creat(2), mkdir(2),
		  rename(2), link(2), and unlink(2).

     st_birthtim  Time when the inode was created.

     These time-related macros are defined for compatibility:

     #define st_atime		     st_atim.tv_sec
     #define st_mtime		     st_mtim.tv_sec
     #define st_ctime		     st_ctim.tv_sec
     #ifndef _POSIX_SOURCE
     #define st_birthtime	     st_birthtim.tv_sec
     #endif

     #ifndef _POSIX_SOURCE
     #define st_atimespec	     st_atim
     #define st_mtimespec	     st_mtim
     #define st_ctimespec	     st_ctim
     #define st_birthtimespec	     st_birthtim
     #endif

     Size-related fields of the struct stat are:

     st_size	 File size in bytes.

     st_blksize  Optimal I/O block size for the file.

     st_blocks	 Actual number of blocks allocated  for  the  file  in	512-byte
		 units.   As  short symbolic links are stored in the inode, this
		 number may be zero.

     The access-related fields of struct stat are:

     st_uid   User ID of the file's owner.

     st_gid   Group ID of the file.

     st_mode  Status of the file (see below).

     The status information word st_mode has these bits:

     #define S_IFMT   0170000  /* type of file mask */
     #define S_IFIFO  0010000  /* named pipe (fifo) */
     #define S_IFCHR  0020000  /* character special */
     #define S_IFDIR  0040000  /* directory */
     #define S_IFBLK  0060000  /* block special */
     #define S_IFREG  0100000  /* regular */
     #define S_IFLNK  0120000  /* symbolic link */
     #define S_IFSOCK 0140000  /* socket */
     #define S_IFWHT  0160000  /* whiteout */
     #define S_ISUID  0004000  /* set user id on execution */
     #define S_ISGID  0002000  /* set group id on execution */
     #define S_ISVTX  0001000  /* save swapped text even after use */
     #define S_IRWXU  0000700  /* RWX mask for owner */
     #define S_IRUSR  0000400  /* read permission, owner */
     #define S_IWUSR  0000200  /* write permission, owner */
     #define S_IXUSR  0000100  /* execute/search permission, owner */
     #define S_IRWXG  0000070  /* RWX mask for group */
     #define S_IRGRP  0000040  /* read permission, group */
     #define S_IWGRP  0000020  /* write permission, group */
     #define S_IXGRP  0000010  /* execute/search permission, group */
     #define S_IRWXO  0000007  /* RWX mask for other */
     #define S_IROTH  0000004  /* read permission, other */
     #define S_IWOTH  0000002  /* write permission, other */
     #define S_IXOTH  0000001  /* execute/search permission, other */

     For a list of access  modes,  see	<sys/stat.h>,  access(2)  and  chmod(2).
     These  macros are available to test whether a st_mode value passed in the m
     argument corresponds to a file of the specified type:

     S_ISBLK(m)   Test for a block special file.

     S_ISCHR(m)   Test for a character special file.

     S_ISDIR(m)   Test for a directory.

     S_ISFIFO(m)  Test for a pipe or FIFO special file.

     S_ISLNK(m)   Test for a symbolic link.

     S_ISREG(m)   Test for a regular file.

     S_ISSOCK(m)  Test for a socket.

     S_ISWHT(m)   Test for a whiteout.

     The macros evaluate to a non-zero value if the test is true or to the value
     0 if the test is false.

RETURN VALUES
     Upon successful completion, the value 0 is returned; otherwise the value -1
     is returned and the global variable errno is set to indicate the error.

COMPATIBILITY
     Previous versions of the  system  used  different	types  for  the  st_dev,
     st_uid, st_gid, st_rdev, st_size, st_blksize and st_blocks fields.

ERRORS
     The stat() and lstat() system calls will fail if:

     [EACCES]		Search	permission is denied for a component of the path
			prefix.

     [EFAULT]		The sb or path argument points to an invalid address.

     [EIO]		An I/O error occurred while reading from or  writing  to
			the file system.

     [EINTEGRITY]	Corrupted  data was detected while reading from the file
			system.

     [ELOOP]		Too many symbolic links were encountered in  translating
			the pathname.

     [ENAMETOOLONG]	A component of a pathname exceeded 255 characters, or an
			entire path name exceeded 1023 characters.

     [ENOENT]		The named file does not exist.

     [ENOTDIR]		A component of the path prefix is not a directory.

     [EOVERFLOW]	The  file  size in bytes cannot be represented correctly
			in the structure pointed to by sb.

     The fstat() system call will fail if:

     [EBADF]		The fd argument is not a valid open file descriptor.

     [EFAULT]		The sb argument points to an invalid address.

     [EIO]		An I/O error occurred while reading from or  writing  to
			the file system.

     [EINTEGRITY]	Corrupted  data was detected while reading from the file
			system.

     [EOVERFLOW]	The file size in bytes cannot be  represented  correctly
			in the structure pointed to by sb.

     In  addition  to the errors returned by the lstat(), the fstatat() may fail
     if:

     [EBADF]		The path argument does not specify an absolute path  and
			the fd argument is neither AT_FDCWD nor a valid file de-
			scriptor open for searching.

     [EINVAL]		The value of the flag argument is not valid.

     [ENOTDIR]		The path argument is not an absolute path and fd is nei-
			ther  AT_FDCWD	nor  a file descriptor associated with a
			directory.

     [ENOTCAPABLE]	path is an absolute path, or contained a ".."  component
			leading  to a directory outside of the directory hierar-
			chy specified by fd, and the process  is  in  capability
			mode or the AT_RESOLVE_BENEATH flag was specified.

SEE ALSO
     access(2),  chmod(2), chown(2), fhstat(2), statfs(2), utimes(2), sticky(7),
     symlink(7)

STANDARDS
     The stat() and fstat() system calls are  expected	to  conform  to  ISO/IEC
     9945-1:1990  ("POSIX.1").	The fstatat() system call follows The Open Group
     Extended API Set 2 specification.

HISTORY
     The stat() and fstat() system calls appeared in Version 1 AT&T  UNIX.   The
     lstat() system call appeared in 4.2BSD.  The fstatat() system call appeared
     in FreeBSD 8.0.

BUGS
     Applying fstat() to a socket returns a zeroed buffer, except for the block-
     size field, and a unique device and inode number.

FreeBSD 13.0			February 23, 2021			 STAT(2)
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