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fstat (2)

fstat (1) ( FreeBSD man: Команды и прикладные программы пользовательского уровня )

fstat (2) ( Solaris man: Системные вызовы )

>> fstat (2) ( FreeBSD man: Системные вызовы )

fstat (2) ( Русские man: Системные вызовы )

fstat (2) ( Linux man: Системные вызовы )

fstat (3) ( Solaris man: Библиотечные вызовы )

fstat (3) ( POSIX man: Библиотечные вызовы )

BSD mandoc

NAME



stat

 
lstat

 
fstat

 - get file status

LIBRARY

Lb libc

SYNOPSIS

#include <sys/types.h>
#include <sys/stat.h>
int stat (const char *path struct stat *sb);
int lstat (const char *path struct stat *sb);
int fstat (int fd struct stat *sb);

DESCRIPTION

The stat ();
system call obtains information about the file pointed to by Fa 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 in the case where the named file is a symbolic 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 Fa fd .

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

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

st_dev: The numeric ID of the device containing the file.
st_ino: The file's inode number.
st_nlink: The number of hard links to the file.

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

The time-related fields of Vt struct stat are as follows:

st_atime: Time when file data last accessed. Changed by the mknod(2), utimes(2), read(2) and readv(2) system calls.
st_mtime: Time when file data last modified. Changed by the mkdir(2), mkfifo(2), mknod(2), utimes(2), write(2) and writev(2) system calls.
st_ctime: Time when file status was last changed (inode data modification). Changed by the chflags(2), chmod(2), chown(2), creat(2), link(2), mkdir(2), mkfifo(2), mknod(2), rename(2), rmdir(2), symlink(2), truncate(2), unlink(2), utimes(2), write(2) and writev(2) system calls.
st_birthtime: Time when the inode was created.

If _POSIX_SOURCE is not defined, the time-related fields are defined as:

#ifndef _POSIX_SOURCE
#define st_atime st_atimespec.tv_sec
#define st_mtime st_mtimespec.tv_sec
#define st_ctime st_ctimespec.tv_sec
#endif

The size-related fields of the Vt struct stat are as follows:

st_size: The file size in bytes.
st_blksize: The optimal I/O block size for the file.
st_blocks: The 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 Vt struct stat are as follows:

st_uid: The user ID of the file's owner.
st_gid: The group ID of the file.
st_mode: Status of the file (see below).

The status information word Fa st_mode has the following 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 In sys/stat.h , access(2) and chmod(2). The following macros are available to test whether a st_mode value passed in the Fa m argument corresponds to a file of the specified type:

Fn S_ISBLK m: Test for a block special file.
Fn S_ISCHR m: Test for a character special file.
Fn S_ISDIR m: Test for a directory.
Fn S_ISFIFO m: Test for a pipe or FIFO special file.
Fn S_ISLNK m: Test for a symbolic link.
Fn S_ISREG m: Test for a regular file.
Fn S_ISSOCK m: Test for a socket.
Fn 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

Rv -std

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:

Bq Er EACCES: Search permission is denied for a component of the path prefix.
Bq Er EFAULT: The Fa sb or Fa path argument points to an invalid address.
Bq Er EIO: An I/O error occurred while reading from or writing to the file system.
Bq Er ELOOP: Too many symbolic links were encountered in translating the pathname.
Bq Er ENAMETOOLONG: A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
Bq Er ENOENT: The named file does not exist.
Bq Er ENOTDIR: A component of the path prefix is not a directory.
Bq Er EOVERFLOW: The file size in bytes cannot be represented correctly in the structure pointed to by Fa sb .

Bq Er EBADF: The Fa fd argument is not a valid open file descriptor.
Bq Er EFAULT: The Fa sb argument points to an invalid address.
Bq Er EIO: An I/O error occurred while reading from or writing to the file system.
Bq Er EOVERFLOW: The file size in bytes cannot be represented correctly in the structure pointed to by Fa sb .