1.\" Copyright (c) 1980, 1991, 1993, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. 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 January 14, 2016 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/stat.h 44.Ft int 45.Fn stat "const char * restrict path" "struct stat * restrict sb" 46.Ft int 47.Fn lstat "const char * restrict path" "struct stat * restrict sb" 48.Ft int 49.Fn fstat "int fd" "struct stat *sb" 50.Ft int 51.Fn fstatat "int fd" "const char *path" "struct stat *buf" "int flag" 52.Sh DESCRIPTION 53The 54.Fn stat 55system call obtains information about the file pointed to by 56.Fa path . 57Read, write or execute 58permission of the named file is not required, but all directories 59listed in the path name leading to the file must be searchable. 60.Pp 61The 62.Fn lstat 63system call is like 64.Fn stat 65except in the case where the named file is a symbolic link, 66in which case 67.Fn lstat 68returns information about the link, 69while 70.Fn stat 71returns information about the file the link references. 72.Pp 73The 74.Fn fstat 75system call obtains the same information about an open file 76known by the file descriptor 77.Fa fd . 78.Pp 79The 80.Fn fstatat 81system call is equivalent to 82.Fn stat 83and 84.Fn lstat 85except in the case where the 86.Fa path 87specifies a relative path. 88In this case the status is retrieved from a file relative to 89the directory associated with the file descriptor 90.Fa fd 91instead of the current working directory. 92.Pp 93The values for the 94.Fa flag 95are constructed by a bitwise-inclusive OR of flags from the following list, 96defined in 97.In fcntl.h : 98.Bl -tag -width indent 99.It Dv AT_SYMLINK_NOFOLLOW 100If 101.Fa path 102names a symbolic link, the status of the symbolic link is returned. 103.El 104.Pp 105If 106.Fn fstatat 107is passed the special value 108.Dv AT_FDCWD 109in the 110.Fa fd 111parameter, the current working directory is used and the behavior is 112identical to a call to 113.Fn stat 114or 115.Fn lstat 116respectively, depending on whether or not the 117.Dv AT_SYMLINK_NOFOLLOW 118bit is set in 119.Fa flag . 120.Pp 121The 122.Fa sb 123argument is a pointer to a 124.Vt stat 125structure 126as defined by 127.In sys/stat.h 128and into which information is placed concerning the file. 129.Pp 130The fields of 131.Vt "struct stat" 132related to the file system are as follows: 133.Bl -tag -width ".Va st_nlink" 134.It Va st_dev 135The numeric ID of the device containing the file. 136.It Va st_ino 137The file's inode number. 138.It Va st_nlink 139The number of hard links to the file. 140.El 141.Pp 142The 143.Va st_dev 144and 145.Va st_ino 146fields together identify the file uniquely within the system. 147.Pp 148The time-related fields of 149.Vt "struct stat" 150are as follows: 151.Bl -tag -width ".Va st_birthtim" 152.It Va st_atim 153Time when file data last accessed. 154Changed by the 155.Xr mknod 2 , 156.Xr utimes 2 , 157.Xr read 2 158and 159.Xr readv 2 160system calls. 161.It Va st_mtim 162Time when file data last modified. 163Changed by the 164.Xr mkdir 2 , 165.Xr mkfifo 2 , 166.Xr mknod 2 , 167.Xr utimes 2 , 168.Xr write 2 169and 170.Xr writev 2 171system calls. 172.It Va st_ctim 173Time when file status was last changed (inode data modification). 174Changed by the 175.Xr chflags 2 , 176.Xr chmod 2 , 177.Xr chown 2 , 178.Xr creat 2 , 179.Xr link 2 , 180.Xr mkdir 2 , 181.Xr mkfifo 2 , 182.Xr mknod 2 , 183.Xr rename 2 , 184.Xr rmdir 2 , 185.Xr symlink 2 , 186.Xr truncate 2 , 187.Xr unlink 2 , 188.Xr utimes 2 , 189.Xr write 2 190and 191.Xr writev 2 192system calls. 193.It Va st_birthtim 194Time when the inode was created. 195.El 196.Pp 197The following time-related macros are defined for compatibility: 198.Bd -literal 199#define st_atime st_atim.tv_sec 200#define st_mtime st_mtim.tv_sec 201#define st_ctime st_ctim.tv_sec 202#ifndef _POSIX_SOURCE 203#define st_birthtime st_birthtim.tv_sec 204#endif 205 206#ifndef _POSIX_SOURCE 207#define st_atimespec st_atim 208#define st_mtimespec st_mtim 209#define st_ctimespec st_ctim 210#define st_birthtimespec st_birthtim 211#endif 212.Ed 213.Pp 214The size-related fields of the 215.Vt "struct stat" 216are as follows: 217.Bl -tag -width ".Va st_blksize" 218.It Va st_size 219The file size in bytes. 220.It Va st_blksize 221The optimal I/O block size for the file. 222.It Va st_blocks 223The actual number of blocks allocated for the file in 512-byte units. 224As short symbolic links are stored in the inode, this number may 225be zero. 226.El 227.Pp 228The access-related fields of 229.Vt "struct stat" 230are as follows: 231.Bl -tag -width ".Va st_mode" 232.It Va st_uid 233The user ID of the file's owner. 234.It Va st_gid 235The group ID of the file. 236.It Va st_mode 237Status of the file (see below). 238.El 239.Pp 240The status information word 241.Fa st_mode 242has the following bits: 243.Bd -literal 244#define S_IFMT 0170000 /* type of file mask */ 245#define S_IFIFO 0010000 /* named pipe (fifo) */ 246#define S_IFCHR 0020000 /* character special */ 247#define S_IFDIR 0040000 /* directory */ 248#define S_IFBLK 0060000 /* block special */ 249#define S_IFREG 0100000 /* regular */ 250#define S_IFLNK 0120000 /* symbolic link */ 251#define S_IFSOCK 0140000 /* socket */ 252#define S_IFWHT 0160000 /* whiteout */ 253#define S_ISUID 0004000 /* set user id on execution */ 254#define S_ISGID 0002000 /* set group id on execution */ 255#define S_ISVTX 0001000 /* save swapped text even after use */ 256#define S_IRWXU 0000700 /* RWX mask for owner */ 257#define S_IRUSR 0000400 /* read permission, owner */ 258#define S_IWUSR 0000200 /* write permission, owner */ 259#define S_IXUSR 0000100 /* execute/search permission, owner */ 260#define S_IRWXG 0000070 /* RWX mask for group */ 261#define S_IRGRP 0000040 /* read permission, group */ 262#define S_IWGRP 0000020 /* write permission, group */ 263#define S_IXGRP 0000010 /* execute/search permission, group */ 264#define S_IRWXO 0000007 /* RWX mask for other */ 265#define S_IROTH 0000004 /* read permission, other */ 266#define S_IWOTH 0000002 /* write permission, other */ 267#define S_IXOTH 0000001 /* execute/search permission, other */ 268.Ed 269.Pp 270For a list of access modes, see 271.In sys/stat.h , 272.Xr access 2 273and 274.Xr chmod 2 . 275The following macros are available to test whether a 276.Va st_mode 277value passed in the 278.Fa m 279argument corresponds to a file of the specified type: 280.Bl -tag -width ".Fn S_ISFIFO m" 281.It Fn S_ISBLK m 282Test for a block special file. 283.It Fn S_ISCHR m 284Test for a character special file. 285.It Fn S_ISDIR m 286Test for a directory. 287.It Fn S_ISFIFO m 288Test for a pipe or FIFO special file. 289.It Fn S_ISLNK m 290Test for a symbolic link. 291.It Fn S_ISREG m 292Test for a regular file. 293.It Fn S_ISSOCK m 294Test for a socket. 295.It Fn S_ISWHT m 296Test for a whiteout. 297.El 298.Pp 299The macros evaluate to a non-zero value if the test is true 300or to the value 0 if the test is false. 301.Sh RETURN VALUES 302.Rv -std 303.Sh COMPATIBILITY 304Previous versions of the system used different types for the 305.Va st_dev , 306.Va st_uid , 307.Va st_gid , 308.Va st_rdev , 309.Va st_size , 310.Va st_blksize 311and 312.Va st_blocks 313fields. 314.Sh ERRORS 315The 316.Fn stat 317and 318.Fn lstat 319system calls will fail if: 320.Bl -tag -width Er 321.It Bq Er EACCES 322Search permission is denied for a component of the path prefix. 323.It Bq Er EFAULT 324The 325.Fa sb 326or 327.Fa path 328argument 329points to an invalid address. 330.It Bq Er EIO 331An I/O error occurred while reading from or writing to the file system. 332.It Bq Er ELOOP 333Too many symbolic links were encountered in translating the pathname. 334.It Bq Er ENAMETOOLONG 335A component of a pathname exceeded 255 characters, 336or an entire path name exceeded 1023 characters. 337.It Bq Er ENOENT 338The named file does not exist. 339.It Bq Er ENOTDIR 340A component of the path prefix is not a directory. 341.It Bq Er EOVERFLOW 342The file size in bytes cannot be 343represented correctly in the structure pointed to by 344.Fa sb . 345.El 346.Pp 347The 348.Fn fstat 349system call will fail if: 350.Bl -tag -width Er 351.It Bq Er EBADF 352The 353.Fa fd 354argument 355is not a valid open file descriptor. 356.It Bq Er EFAULT 357The 358.Fa sb 359argument 360points to an invalid address. 361.It Bq Er EIO 362An I/O error occurred while reading from or writing to the file system. 363.It Bq Er EOVERFLOW 364The file size in bytes cannot be 365represented correctly in the structure pointed to by 366.Fa sb . 367.El 368.Pp 369In addition to the errors returned by the 370.Fn lstat , 371the 372.Fn fstatat 373may fail if: 374.Bl -tag -width Er 375.It Bq Er EBADF 376The 377.Fa path 378argument does not specify an absolute path and the 379.Fa fd 380argument is neither 381.Dv AT_FDCWD 382nor a valid file descriptor open for searching. 383.It Bq Er EINVAL 384The value of the 385.Fa flag 386argument is not valid. 387.It Bq Er ENOTDIR 388The 389.Fa path 390argument is not an absolute path and 391.Fa fd 392is neither 393.Dv AT_FDCWD 394nor a file descriptor associated with a directory. 395.El 396.Sh SEE ALSO 397.Xr access 2 , 398.Xr chmod 2 , 399.Xr chown 2 , 400.Xr fhstat 2 , 401.Xr statfs 2 , 402.Xr utimes 2 , 403.Xr sticky 7 , 404.Xr symlink 7 405.Sh STANDARDS 406The 407.Fn stat 408and 409.Fn fstat 410system calls are expected to conform to 411.St -p1003.1-90 . 412The 413.Fn fstatat 414system call follows The Open Group Extended API Set 2 specification. 415.Sh HISTORY 416The 417.Fn stat 418and 419.Fn fstat 420system calls appeared in 421.At v7 . 422The 423.Fn lstat 424system call appeared in 425.Bx 4.2 . 426The 427.Fn fstatat 428system call appeared in 429.Fx 8.0 . 430.Sh BUGS 431Applying 432.Fn fstat 433to a socket 434returns a zeroed buffer, 435except for the blocksize field, 436and a unique device and inode number. 437