stat(2) SYSTEM CALLS 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);
int fstat(int fildes, struct stat *buf);
DESCRIPTION
path points to a path name naming a file. 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. stat obtains information about the
named file.
Note that in a Remote File Sharing environment, the informa-
tion returned by stat depends on the user/group mapping set
up between the local and remote computers. [See idload(1M).]
lstat obtains file attributes similar to stat, except when
the named file is a symbolic link; in that case lstat
returns information about the link, while stat returns
information about the file the link references.
fstat obtains information about an open file known by the
file descriptor fildes, obtained from a successful open,
creat, dup, fcntl, or pipe system call.
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 include the
following members:
modet stmode; /* File mode [see mknod(2)] */
inot stino; /* Inode number */
devt stdev; /* ID of device containing */
/* a directory entry for this file */
devt strdev; /* ID of device */
/* This entry is defined only for */
/* char special or block special files */
nlinkt stnlink; /* Number of links */
uidt stuid; /* User ID of the file's owner */
gidt stgid; /* Group ID of the file's group */
offt stsize; /* File size in bytes */
timet statime; /* Time of last access */
timet stmtime; /* Time of last data modification */
timet stctime; /* Time of last file status change */
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stat(2) SYSTEM CALLS stat(2)
/* Times measured in seconds since */
/* 00:00:00 UTC, Jan. 1, 1970 */
long stblksize; /* Preferred I/O block size */
long stblocks; /* Number stblksize blocks allocated */
stmode The mode of the file as described in mknod(2). In
addition to the modes described in mknod(2), the
mode of a file may also be S_IFLNK if the file is
a symbolic link. (Note that S_IFLNK may only be
returned by lstat.)
stino This field uniquely identifies the file in a given
file system. The pair stino and stdev uniquely
identifies regular files.
stdev This field uniquely identifies the file system
that contains the file. Its value may be used as
input to the ustat system call to determine more
information about this file system. No other
meaning is associated with this value.
strdev This field should be used only by administrative
commands. It is valid only for block special or
character special files and only has meaning on
the system where the file was configured.
stnlink This field should be used only by administrative
commands.
stuid The user ID of the file's owner.
stgid The group ID of the file's group.
stsize For regular files, this is the address of the end
of the file. For block special or character spe-
cial, this is not defined. See also pipe(2).
statime Time when file data was last accessed. Changed by
the following system calls: creat, mknod, pipe,
utime, and read.
stmtime Time when data was last modified. Changed by the
following system calls: creat, mknod, pipe,
utime, and write.
stctime Time when file status was last changed. Changed
by the following system calls: chmod, chown,
creat, link, mknod, pipe, unlink, utime, and
write.
stblksize
A hint as to the "best" unit size for I/O
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stat(2) SYSTEM CALLS stat(2)
operations. This field is not defined for block-
special or character-special files.
stblocks The total number of physical blocks of size 512
bytes actually allocated on disk. This field is
not defined for block-special or character-special
files.
stat and lstat fail if one or more of the following are
true:
EACCES Search permission is denied for a com-
ponent of the path prefix.
EFAULT buf or path points to an invalid
address.
EINTR A signal was caught during the stat or
lstat system call.
ELOOP Too many symbolic links were encountered
in translating path.
EMULTIHOP Components of path require hopping to
multiple remote machines and the file
system does not allow it.
ENAMETOOLONG The length of the path argument exceeds
{PATHMAX}, or the length of a path com-
ponent exceeds {NAMEMAX} while
POSIXNOTRUNC is in effect.
ENOENT The named file does not exist or is the
null pathname.
ENOTDIR A component of the path prefix is not a
directory.
ENOLINK path points to a remote machine and the
link to that machine is no longer
active.
EOVERFLOW A component is too large to store in the
structure pointed to by buf.
fstat fails if one or more of the following are true:
EBADF fildes is not a valid open file descrip-
tor.
EFAULT buf points to an invalid address.
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stat(2) SYSTEM CALLS stat(2)
EINTR A signal was caught during the fstat
system call.
ENOLINK fildes points to a remote machine and
the link to that machine is no longer
active.
EOVERFLOW A component is too large to store in the
structure pointed to by buf.
SEE ALSO
chmod(2), chown(2), creat(2), link(2), mknod(2), pipe(2),
read(2), time(2), unlink(2), utime(2), write(2),
fattach(3C), stat(5).
DIAGNOSTICS
Upon successful completion a value of 0 is returned. Other-
wise, a value of -1 is returned and errno is set to indicate
the error.
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