xref: /freebsd-14.2/lib/libc/sys/stat.2 (revision fffcbbcd)
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32.\"     @(#)stat.2	8.4 (Berkeley) 5/1/95
33.\" $FreeBSD$
34.\"
35.Dd May 1, 1995
36.Dt STAT 2
37.Os
38.Sh NAME
39.Nm stat ,
40.Nm lstat ,
41.Nm fstat
42.Nd get file status
43.Sh LIBRARY
44.Lb libc
45.Sh SYNOPSIS
46.Fd #include <sys/types.h>
47.Fd #include <sys/stat.h>
48.Ft int
49.Fn stat "const char *path" "struct stat *sb"
50.Ft int
51.Fn lstat "const char *path" "struct stat *sb"
52.Ft int
53.Fn fstat "int fd" "struct stat *sb"
54.Sh DESCRIPTION
55The
56.Fn stat
57function obtains information about the file pointed to by
58.Fa path .
59Read, write or execute
60permission of the named file is not required, but all directories
61listed in the path name leading to the file must be searchable.
62.Pp
63.Fn Lstat
64is like
65.Fn stat
66except in the case where the named file is a symbolic link,
67in which case
68.Fn lstat
69returns information about the link,
70while
71.Fn stat
72returns information about the file the link references.
73.Pp
74The
75.Fn fstat
76obtains the same information about an open file
77known by the file descriptor
78.Fa fd .
79.Pp
80The
81.Fa sb
82argument is a pointer to a
83.Fn stat
84structure
85as defined by
86.Aq Pa sys/stat.h
87(shown below)
88and into which information is placed concerning the file.
89.Bd -literal
90struct stat {
91    dev_t     st_dev;               /* inode's device */
92    ino_t     st_ino;               /* inode's number */
93    mode_t    st_mode;              /* inode protection mode */
94    nlink_t   st_nlink;             /* number of hard links */
95    uid_t     st_uid;               /* user ID of the file's owner */
96    gid_t     st_gid;               /* group ID of the file's group */
97    dev_t     st_rdev;              /* device type */
98#ifndef _POSIX_SOURCE
99    struct timespec st_atimespec;  /* time of last access */
100    struct timespec st_mtimespec;  /* time of last data modification */
101    struct timespec st_ctimespec;  /* time of last file status change */
102#else
103    time_t    st_atime;             /* time of last access */
104    long      st_atimensec;         /* nsec of last access */
105    time_t    st_mtime;             /* time of last data modification */
106    long      st_mtimensec;         /* nsec of last data modification */
107    time_t    st_ctime;             /* time of last file status change */
108    long      st_ctimensec;         /* nsec of last file status change */
109#endif
110    off_t     st_size;              /* file size, in bytes */
111    int64_t   st_blocks;            /* blocks allocated for file */
112    u_int32_t st_blksize;           /* optimal blocksize for I/O */
113    u_int32_t st_flags;             /* user defined flags for file */
114    u_int32_t st_gen;               /* file generation number */
115};
116.Ed
117.Pp
118The time-related fields of
119.Fa struct stat
120are as follows:
121.Bl -tag -width XXXst_mtime
122.It st_atime
123Time when file data last accessed.
124Changed by the
125.Xr mknod 2 ,
126.Xr utimes 2
127and
128.Xr read 2
129system calls.
130.It st_mtime
131Time when file data last modified.
132Changed by the
133.Xr mknod 2 ,
134.Xr utimes 2
135and
136.Xr write 2
137system calls.
138.It st_ctime
139Time when file status was last changed (inode data modification).
140Changed by the
141.Xr chmod 2 ,
142.Xr chown 2 ,
143.Xr link 2 ,
144.Xr mknod 2 ,
145.Xr rename 2 ,
146.Xr unlink 2 ,
147.Xr utimes 2
148and
149.Xr write 2
150system calls.
151.El
152.Pp
153If
154.Dv _POSIX_SOURCE
155is not defined, the time-related fields are defined as:
156.Bd -literal
157#ifndef _POSIX_SOURCE
158#define st_atime st_atimespec.tv_sec
159#define st_mtime st_mtimespec.tv_sec
160#define st_ctime st_ctimespec.tv_sec
161#endif
162.Ed
163.Pp
164The size-related fields of the
165.Fa struct stat
166are as follows:
167.Bl -tag -width XXXst_blksize
168.It st_blksize
169The optimal I/O block size for the file.
170.It st_blocks
171The actual number of blocks allocated for the file in 512-byte units.
172As short symbolic links are stored in the inode, this number may
173be zero.
174.El
175.Pp
176The status information word
177.Fa st_mode
178has the following bits:
179.Bd -literal
180#define S_IFMT 0170000           /* type of file */
181#define        S_IFIFO  0010000  /* named pipe (fifo) */
182#define        S_IFCHR  0020000  /* character special */
183#define        S_IFDIR  0040000  /* directory */
184#define        S_IFBLK  0060000  /* block special */
185#define        S_IFREG  0100000  /* regular */
186#define        S_IFLNK  0120000  /* symbolic link */
187#define        S_IFSOCK 0140000  /* socket */
188#define        S_IFWHT  0160000  /* whiteout */
189#define S_ISUID 0004000  /* set user id on execution */
190#define S_ISGID 0002000  /* set group id on execution */
191#define S_ISVTX 0001000  /* save swapped text even after use */
192#define S_IRUSR 0000400  /* read permission, owner */
193#define S_IWUSR 0000200  /* write permission, owner */
194#define S_IXUSR 0000100  /* execute/search permission, owner */
195.Ed
196.Pp
197For a list of access modes, see
198.Aq Pa sys/stat.h ,
199.Xr access 2
200and
201.Xr chmod 2 .
202.Sh RETURN VALUES
203Upon successful completion a value of 0 is returned.
204Otherwise, a value of -1 is returned and
205.Va errno
206is set to indicate the error.
207.Sh COMPATIBILITY
208Previous versions of the system used different types for the
209.Li st_dev ,
210.Li st_uid ,
211.Li st_gid ,
212.Li st_rdev ,
213.Li st_size ,
214.Li st_blksize
215and
216.Li st_blocks
217fields.
218.Sh ERRORS
219.Fn Stat
220and
221.Fn lstat
222will fail if:
223.Bl -tag -width Er
224.It Bq Er ENOTDIR
225A component of the path prefix is not a directory.
226.It Bq Er ENAMETOOLONG
227A component of a pathname exceeded 255 characters,
228or an entire path name exceeded 1023 characters.
229.It Bq Er ENOENT
230The named file does not exist.
231.It Bq Er EACCES
232Search permission is denied for a component of the path prefix.
233.It Bq Er ELOOP
234Too many symbolic links were encountered in translating the pathname.
235.It Bq Er EFAULT
236.Fa sb
237or
238.Em name
239points to an invalid address.
240.It Bq Er EIO
241An I/O error occurred while reading from or writing to the file system.
242.El
243.Pp
244.Bl -tag -width Er
245.Fn Fstat
246will fail if:
247.It Bq Er EBADF
248.Fa fd
249is not a valid open file descriptor.
250.It Bq Er EFAULT
251.Fa sb
252points to an invalid address.
253.It Bq Er EIO
254An I/O error occurred while reading from or writing to the file system.
255.El
256.Sh SEE ALSO
257.Xr access 2 ,
258.Xr chmod 2 ,
259.Xr chown 2 ,
260.Xr utimes 2 ,
261.Xr symlink 7
262.Sh BUGS
263Applying
264.Fn fstat
265to a socket (and thus to a pipe)
266returns a zeroed buffer,
267except for the blocksize field,
268and a unique device and inode number.
269.Sh STANDARDS
270The
271.Fn stat
272and
273.Fn fstat
274function calls are expected to conform to
275.St -p1003.1-90 .
276.Sh HISTORY
277A
278.Fn stat
279and a
280.Fn fstat
281function call appeared in
282.At v7 .
283A
284.Fn lstat
285function call appeared in
286.Bx 4.2 .
287