stat(2)
NAME
stat, lstat, fstat - get file status
SYNOPSIS
#include <sys/types.h>
#include <sys/stat.h>
int stat(const char *path, struct stat *buf)
int lstat(const char *path, struct stat *buf) (Minix-vmd)
int fstat(int fd, struct stat *buf)
DESCRIPTION
Stat obtains information about the file 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 reachable.
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. (Minix-vmd)
Fstat obtains the same information about an open file referenced by the
argument descriptor, such as would be obtained by an open call. Pipe
descriptors look like named pipes with a link count of zero. The st_size
field of pipes or named pipes shows the amount of bytes currently
buffered in the pipe.
Buf is a pointer to a stat structure into which information is placed
concerning the file. The contents of the structure pointed to by buf is
as follows:
struct stat {
dev_t st_dev; /* device inode resides on */
ino_t st_ino; /* this inode's number */
mode_t st_mode; /* file mode, protection bits, etc. */
nlink_t st_nlink; /* number or hard links to the file */
uid_t st_uid; /* user-id of the file's owner */
gid_t st_gid; /* group-id of the file's owner */
dev_t st_rdev; /* the device type, for inode that is device */
off_t st_size; /* total size of file */
time_t st_atime; /* time of last access */
time_t st_mtime; /* time of last data modification */
time_t st_ctime; /* time of last file status change */
};
st_atime Time when file data was last read or modified. Changed by
the following system calls: mknod(2), utime(2), read(2), and
write(2). For reasons of efficiency, st_atime is not set
when a directory is searched, although this would be more
logical.
st_mtime Time when data was last modified. It is not set by changes
of owner, group, link count, or mode. Changed by the
following system calls: mknod(2), utime(2), write(2).
st_ctime Time when file status was last changed. It is set both both
by writing and changing the i-node. Changed by the following
system calls: chmod(2) chown(2), link(2), mknod(2),
rename(2), unlink(2), utime(2), write(2).
The file type information in st_mode has bits:
#define S_IFMT 0170000 /* type of file */
#define S_IFIFO 0010000 /* named pipe */
#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 (Minix-vmd) */
The mode bits 0007777 encode set-uid/gid bits and permission bits (see
chmod(2)).
RETURN VALUE
Upon successful completion a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate the error.
ERRORS
Stat and lstat will fail if one or more of the following are true:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] The path name exceeds PATH_MAX characters.
[ENOENT] The named file does not exist.
[EACCES] Search permission is denied for a component of the path
prefix.
[ELOOP] Too many symbolic links were encountered in translating
the pathname. (Minix-vmd)
[EFAULT] Buf or name points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to the
file system.
Fstat will fail if one or both of the following are true:
[EBADF] Fildes is not a valid open file descriptor.
[EFAULT] Buf points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to the
file system.
SEE ALSO
chmod(2), chown(2), utime(2).