int
stat(const char *path, struct stat *sb)
int
lstat(const char *path, struct stat *sb)
int
fstat(int fd, struct stat *sb)
)
function 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.
lstat()
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()
function obtains the same information about an open file
known by the file descriptor
fd.
The
sb
argument is a pointer to a
stat
structure
as defined by
<sys/stat.h>
(shown below)
and into which information is placed concerning the file.
struct stat {
dev_t st_dev; /* device containing the file */
ino_t st_ino; /* file's serial number */
mode_t st_mode; /* file's mode (protection and type) */
nlink_t st_nlink; /* number of hard links to the file */
uid_t st_uid; /* user-id of owner */
gid_t st_gid; /* group-id of owner */
dev_t st_rdev; /* device type, for device special file */
#if defined(_NETBSD_SOURCE)
struct timespec st_atimespec; /* time of last access */
struct timespec st_mtimespec; /* time of last data modification */
struct timespec st_ctimespec; /* time of last file status change */
#else
time_t st_atime; /* time of last access */
long st_atimensec; /* nsec of last access */
time_t st_mtime; /* time of last data modification */
long st_mtimensec; /* nsec of last data modification */
time_t st_ctime; /* time of last file status change */
long st_ctimensec; /* nsec of last file status change */
#endif
off_t st_size; /* file size, in bytes */
blkcnt_t st_blocks; /* blocks allocated for file */
blksize_t st_blksize; /* optimal file sys I/O ops blocksize */
uint32_t st_flags; /* user defined flags for file */
uint32_t st_gen; /* file generation number */
#if defined(_NETBSD_SOURCE)
struct timespec st_birthtimespec; /* time of inode creation */
#else
time_t st_birthtime; /* time of inode creation */
long st_birthtimensec; /* nsec of inode creation */
#endif
};
The time-related fields of
struct stat
are as follows:
If
_NETBSD_SOURCE
is defined, the time-related fields are defined as:
#if defined(_NETBSD_SOURCE)
#define st_atime st_atimespec.tv_sec
#define st_atimensec st_atimespec.tv_nsec
#define st_mtime st_mtimespec.tv_sec
#define st_mtimensec st_mtimespec.tv_nsec
#define st_ctime st_ctimespec.tv_sec
#define st_ctimensec st_ctimespec.tv_nsec
#define st_birthtime st_birthtimespec.tv_sec
#define st_birthtimensec st_birthtimespec.tv_nsec
#endif
The size-related fields of the
struct stat
are as follows:
The status information word
st_mode
has the following bits:
#define S_IFMT 0170000 /* type of file */
#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_IRUSR 0000400 /* read permission, owner */
#define S_IWUSR 0000200 /* write permission, owner */
#define S_IXUSR 0000100 /* execute/search permission, owner */
#define S_IRGRP 0000040 /* read permission, group */
#define S_IWGRP 0000020 /* write permission, group */
#define S_IXGRP 0000010 /* execute/search permission, group */
#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).
The status information word
st_flags
has the following bits:
#define UF_NODUMP 0x00000001 /* do not dump file */
#define UF_IMMUTABLE 0x00000002 /* file may not be changed */
#define UF_APPEND 0x00000004 /* writes to file may only append */
#define UF_OPAQUE 0x00000008 /* directory is opaque wrt. union */
#define SF_ARCHIVED 0x00010000 /* file is archived */
#define SF_IMMUTABLE 0x00020000 /* file may not be changed */
#define SF_APPEND 0x00040000 /* writes to file may only append */
For a description of the flags, see chflags(2).
st_dev,
st_uid,
st_gid,
st_rdev,
st_size,
st_blksize
and
st_blocks
fields.
)
and
lstat()
will fail if:
ENOTDIR]ENAMETOOLONG]{NAME_MAX}
characters, or an entire path name exceeded
{PATH_MAX}
characters.
ENOENT]EACCES]ELOOP]EFAULT]sb
or
name
points to an invalid address.
ENXIO]EIO]EBADF]
)
will fail if:
EBADF]fd
is not a valid open file descriptor.
EFAULT]sb
points to an invalid address.
EIO])
and
fstat()
functions conform to
ISO/IEC 9945-1:1990 (``POSIX.1'') .
)
function call appeared in
4.2BSD.
)
to a socket (and thus to a pipe)
returns a zero'd buffer,
except for the blocksize field,
and a unique device and file serial number.