stat.2

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.th STAT II 8/5/73
.sh NAME
stat \*- get file status
.sh SYNOPSIS
(stat = 18.)
.br
.ft B
sys stat; name; buf
.s3
stat(name, buf)
.br
char *name;
.br
struct inode *buf;
.ft R
.sh DESCRIPTION
.it Name
points to a null-terminated string naming
a file;
.it buf
is the address of a 36(10) byte buffer
into which information is placed concerning the file.
It is unnecessary to have any
permissions at all with respect to the file, but all directories
leading to the file must be readable.
After
.it stat,
.it buf
has the following structure (starting offset given in bytes):
.s3
.if t .ta .5i 1i 2.5i
.if n .ta 3 9 24
.nf
struct inode {
	char	minor;	/* +0: minor device of i-node */
	char	major;	/* +1: major device */
	int	inumber;	/* +2 */
	int	flags;	/* +4: see below */
	char	nlinks;	/* +6: number of links to file */
	char	uid;	/* +7: user ID of owner */
	char	gid;	/* +8: group ID of owner */
	char	size0;	/* +9: high byte of 24-bit size */
	int	size1;	/* +10: low word of 24-bit size */
	int	addr[8];	/* +12: block numbers or device number */
	int	actime[2];	/* +28: time of last access */
	int	modtime[2];	/* +32: time of last modification */
};
.fi
.s3
The flags are as follows:
.s3
.lp +10 9
100000	i-node is allocated
.lp +10 9
060000	2-bit file type:
.lp +15 9
000000	plain file
.lp +15 9
040000	directory
.lp +15 9
020000	character-type special file
.lp +15 9
060000	block-type special file.
.lp +10 9
010000	large file
.lp +10 9
004000	set user-ID on execution
.lp +10 9
002000	set group-ID on execution
.lp +10 9
001000	save text image after execution
.lp +10 9
000400	read (owner)
.lp +10 9
000200	write (owner)
.lp +10 9
000100	execute (owner)
.lp +10 9
000070	read, write, execute (group)
.lp +10 9
000007	read, write, execute (others)
.i0
.sh "SEE ALSO"
ls (I), fstat (II), fs (V)
.sh DIAGNOSTICS
Error bit (c-bit)
is set if the file cannot be found.
From C, a \*-1 return indicates an error.