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Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)stat.2 8.4 (Berkeley) 5/1/95 29.\" $FreeBSD$ 30.\" 31.Dd June 2, 2012 32.Dt STAT 2 33.Os 34.Sh NAME 35.Nm stat , 36.Nm lstat , 37.Nm fstat , 38.Nm fstatat 39.Nd get file status 40.Sh LIBRARY 41.Lb libc 42.Sh SYNOPSIS 43.In sys/types.h 44.In sys/stat.h 45.Ft int 46.Fn stat "const char *path" "struct stat *sb" 47.Ft int 48.Fn lstat "const char *path" "struct stat *sb" 49.Ft int 50.Fn fstat "int fd" "struct stat *sb" 51.Ft int 52.Fn fstatat "int fd" "const char *path" "struct stat *buf" "int flag" 53.Sh DESCRIPTION 54The 55.Fn stat 56system call obtains information about the file pointed to by 57.Fa path . 58Read, write or execute 59permission of the named file is not required, but all directories 60listed in the path name leading to the file must be searchable. 61.Pp 62The 63.Fn lstat 64system call is 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 76system call obtains the same information about an open file 77known by the file descriptor 78.Fa fd . 79.Pp 80The 81.Fn fstatat 82system call is equivalent to 83.Fn stat 84and 85.Fn lstat 86except in the case where the 87.Fa path 88specifies a relative path. 89In this case the status is retrieved from a file relative to 90the directory associated with the file descriptor 91.Fa fd 92instead of the current working directory. 93.Pp 94The values for the 95.Fa flag 96are constructed by a bitwise-inclusive OR of flags from the following list, 97defined in 98.In fcntl.h : 99.Bl -tag -width indent 100.It Dv AT_SYMLINK_NOFOLLOW 101If 102.Fa path 103names a symbolic link, the status of the symbolic link is returned. 104.El 105.Pp 106If 107.Fn fstatat 108is passed the special value 109.Dv AT_FDCWD 110in the 111.Fa fd 112parameter, the current working directory is used and the behavior is 113identical to a call to 114.Fn stat 115or 116.Fn lstat 117respectively, depending on whether or not the 118.Dv AT_SYMLINK_NOFOLLOW 119bit is set in 120.Fa flag . 121.Pp 122The 123.Fa sb 124argument is a pointer to a 125.Vt stat 126structure 127as defined by 128.In sys/stat.h 129and into which information is placed concerning the file. 130.Pp 131The fields of 132.Vt "struct stat" 133related to the file system are as follows: 134.Bl -tag -width ".Va st_nlink" 135.It Va st_dev 136The numeric ID of the device containing the file. 137.It Va st_ino 138The file's inode number. 139.It Va st_nlink 140The number of hard links to the file. 141.El 142.Pp 143The 144.Va st_dev 145and 146.Va st_ino 147fields together identify the file uniquely within the system. 148.Pp 149The time-related fields of 150.Vt "struct stat" 151are as follows: 152.Bl -tag -width ".Va st_birthtim" 153.It Va st_atim 154Time when file data last accessed. 155Changed by the 156.Xr mknod 2 , 157.Xr utimes 2 , 158.Xr read 2 159and 160.Xr readv 2 161system calls. 162.It Va st_mtim 163Time when file data last modified. 164Changed by the 165.Xr mkdir 2 , 166.Xr mkfifo 2 , 167.Xr mknod 2 , 168.Xr utimes 2 , 169.Xr write 2 170and 171.Xr writev 2 172system calls. 173.It Va st_ctim 174Time when file status was last changed (inode data modification). 175Changed by the 176.Xr chflags 2 , 177.Xr chmod 2 , 178.Xr chown 2 , 179.Xr creat 2 , 180.Xr link 2 , 181.Xr mkdir 2 , 182.Xr mkfifo 2 , 183.Xr mknod 2 , 184.Xr rename 2 , 185.Xr rmdir 2 , 186.Xr symlink 2 , 187.Xr truncate 2 , 188.Xr unlink 2 , 189.Xr utimes 2 , 190.Xr write 2 191and 192.Xr writev 2 193system calls. 194.It Va st_birthtim 195Time when the inode was created. 196.El 197.Pp 198The following time-related macros are defined for compatibility: 199.Bd -literal 200#define st_atime st_atim.tv_sec 201#define st_mtime st_mtim.tv_sec 202#define st_ctime st_ctim.tv_sec 203#ifndef _POSIX_SOURCE 204#define st_birthtime st_birthtim.tv_sec 205#endif 206 207#ifndef _POSIX_SOURCE 208#define st_atimespec st_atim 209#define st_mtimespec st_mtim 210#define st_ctimespec st_ctim 211#define st_birthtimespec st_birthtim 212#endif 213.Ed 214.Pp 215The size-related fields of the 216.Vt "struct stat" 217are as follows: 218.Bl -tag -width ".Va st_blksize" 219.It Va st_size 220The file size in bytes. 221.It Va st_blksize 222The optimal I/O block size for the file. 223.It Va st_blocks 224The actual number of blocks allocated for the file in 512-byte units. 225As short symbolic links are stored in the inode, this number may 226be zero. 227.El 228.Pp 229The access-related fields of 230.Vt "struct stat" 231are as follows: 232.Bl -tag -width ".Va st_mode" 233.It Va st_uid 234The user ID of the file's owner. 235.It Va st_gid 236The group ID of the file. 237.It Va st_mode 238Status of the file (see below). 239.El 240.Pp 241The status information word 242.Fa st_mode 243has the following bits: 244.Bd -literal 245#define S_IFMT 0170000 /* type of file mask */ 246#define S_IFIFO 0010000 /* named pipe (fifo) */ 247#define S_IFCHR 0020000 /* character special */ 248#define S_IFDIR 0040000 /* directory */ 249#define S_IFBLK 0060000 /* block special */ 250#define S_IFREG 0100000 /* regular */ 251#define S_IFLNK 0120000 /* symbolic link */ 252#define S_IFSOCK 0140000 /* socket */ 253#define S_IFWHT 0160000 /* whiteout */ 254#define S_ISUID 0004000 /* set user id on execution */ 255#define S_ISGID 0002000 /* set group id on execution */ 256#define S_ISVTX 0001000 /* save swapped text even after use */ 257#define S_IRWXU 0000700 /* RWX mask for owner */ 258#define S_IRUSR 0000400 /* read permission, owner */ 259#define S_IWUSR 0000200 /* write permission, owner */ 260#define S_IXUSR 0000100 /* execute/search permission, owner */ 261#define S_IRWXG 0000070 /* RWX mask for group */ 262#define S_IRGRP 0000040 /* read permission, group */ 263#define S_IWGRP 0000020 /* write permission, group */ 264#define S_IXGRP 0000010 /* execute/search permission, group */ 265#define S_IRWXO 0000007 /* RWX mask for other */ 266#define S_IROTH 0000004 /* read permission, other */ 267#define S_IWOTH 0000002 /* write permission, other */ 268#define S_IXOTH 0000001 /* execute/search permission, other */ 269.Ed 270.Pp 271For a list of access modes, see 272.In sys/stat.h , 273.Xr access 2 274and 275.Xr chmod 2 . 276The following macros are available to test whether a 277.Va st_mode 278value passed in the 279.Fa m 280argument corresponds to a file of the specified type: 281.Bl -tag -width ".Fn S_ISFIFO m" 282.It Fn S_ISBLK m 283Test for a block special file. 284.It Fn S_ISCHR m 285Test for a character special file. 286.It Fn S_ISDIR m 287Test for a directory. 288.It Fn S_ISFIFO m 289Test for a pipe or FIFO special file. 290.It Fn S_ISLNK m 291Test for a symbolic link. 292.It Fn S_ISREG m 293Test for a regular file. 294.It Fn S_ISSOCK m 295Test for a socket. 296.It Fn S_ISWHT m 297Test for a whiteout. 298.El 299.Pp 300The macros evaluate to a non-zero value if the test is true 301or to the value 0 if the test is false. 302.Sh RETURN VALUES 303.Rv -std 304.Sh COMPATIBILITY 305Previous versions of the system used different types for the 306.Va st_dev , 307.Va st_uid , 308.Va st_gid , 309.Va st_rdev , 310.Va st_size , 311.Va st_blksize 312and 313.Va st_blocks 314fields. 315.Sh ERRORS 316The 317.Fn stat 318and 319.Fn lstat 320system calls will fail if: 321.Bl -tag -width Er 322.It Bq Er EACCES 323Search permission is denied for a component of the path prefix. 324.It Bq Er EFAULT 325The 326.Fa sb 327or 328.Fa path 329argument 330points to an invalid address. 331.It Bq Er EIO 332An I/O error occurred while reading from or writing to the file system. 333.It Bq Er ELOOP 334Too many symbolic links were encountered in translating the pathname. 335.It Bq Er ENAMETOOLONG 336A component of a pathname exceeded 255 characters, 337or an entire path name exceeded 1023 characters. 338.It Bq Er ENOENT 339The named file does not exist. 340.It Bq Er ENOTDIR 341A component of the path prefix is not a directory. 342.It Bq Er EOVERFLOW 343The file size in bytes cannot be 344represented correctly in the structure pointed to by 345.Fa sb . 346.El 347.Pp 348The 349.Fn fstat 350system call will fail if: 351.Bl -tag -width Er 352.It Bq Er EBADF 353The 354.Fa fd 355argument 356is not a valid open file descriptor. 357.It Bq Er EFAULT 358The 359.Fa sb 360argument 361points to an invalid address. 362.It Bq Er EIO 363An I/O error occurred while reading from or writing to the file system. 364.It Bq Er EOVERFLOW 365The file size in bytes cannot be 366represented correctly in the structure pointed to by 367.Fa sb . 368.El 369.Pp 370In addition to the errors returned by the 371.Fn lstat , 372the 373.Fn fstatat 374may fail if: 375.Bl -tag -width Er 376.It Bq Er EBADF 377The 378.Fa path 379argument does not specify an absolute path and the 380.Fa fd 381argument is neither 382.Dv AT_FDCWD 383nor a valid file descriptor open for searching. 384.It Bq Er EINVAL 385The value of the 386.Fa flag 387argument is not valid. 388.It Bq Er ENOTDIR 389The 390.Fa path 391argument is not an absolute path and 392.Fa fd 393is neither 394.Dv AT_FDCWD 395nor a file descriptor associated with a directory. 396.El 397.Sh SEE ALSO 398.Xr access 2 , 399.Xr chmod 2 , 400.Xr chown 2 , 401.Xr fhstat 2 , 402.Xr statfs 2 , 403.Xr utimes 2 , 404.Xr sticky 7 , 405.Xr symlink 7 406.Sh STANDARDS 407The 408.Fn stat 409and 410.Fn fstat 411system calls are expected to conform to 412.St -p1003.1-90 . 413The 414.Fn fstatat 415system call follows The Open Group Extended API Set 2 specification. 416.Sh HISTORY 417The 418.Fn stat 419and 420.Fn fstat 421system calls appeared in 422.At v7 . 423The 424.Fn lstat 425system call appeared in 426.Bx 4.2 . 427The 428.Fn fstatat 429system call appeared in 430.Fx 8.0 . 431.Sh BUGS 432Applying 433.Fn fstat 434to a socket 435returns a zeroed buffer, 436except for the blocksize field, 437and a unique device and inode number. 438