| 1 | .\" Copyright (c) 1980 Regents of the University of California.
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| 2 | .\" All rights reserved. The Berkeley software License Agreement
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| 3 | .\" specifies the terms and conditions for redistribution.
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| 4 | .\"
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| 5 | .\" @(#)stat.2 6.5 (Berkeley) 5/12/86
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| 6 | .\"
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| 7 | .TH STAT 2 "May 12, 1986"
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| 8 | .UC 4
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| 9 | .SH NAME
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| 10 | stat, lstat, fstat \- get file status
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| 11 | .SH SYNOPSIS
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| 12 | .nf
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| 13 | .ft B
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| 14 | #include <sys/types.h>
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| 15 | #include <sys/stat.h>
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| 16 |
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| 17 | .ta +54n
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| 18 | int stat(const char *\fIpath\fP, struct stat *\fIbuf\fP)
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| 19 | int lstat(const char *\fIpath\fP, struct stat *\fIbuf\fP)
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| 20 | int fstat(int \fIfd\fP, struct stat *\fIbuf\fP)
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| 21 | .fi
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| 22 | .ft R
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| 23 | .SH DESCRIPTION
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| 24 | .B Stat
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| 25 | obtains information about the file
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| 26 | .IR path .
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| 27 | Read, write or execute
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| 28 | permission of the named file is not required, but all directories
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| 29 | listed in the path name leading to the file must be reachable.
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| 30 | .PP
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| 31 | .B Lstat
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| 32 | is like \fBstat\fP except in the case where the named file is a symbolic link,
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| 33 | in which case
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| 34 | .B lstat
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| 35 | returns information about the link,
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| 36 | while
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| 37 | .B stat
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| 38 | returns information about the file the link references.
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| 39 | .PP
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| 40 | .B Fstat
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| 41 | obtains the same information about an open file
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| 42 | referenced by the argument descriptor, such as would
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| 43 | be obtained by an \fBopen\fP call. Pipe descriptors
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| 44 | look like named pipes with a link count of zero. The
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| 45 | st_size field of pipes or named pipes shows the amount of
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| 46 | bytes currently buffered in the pipe.
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| 47 | .PP
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| 48 | .I Buf
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| 49 | is a pointer to a
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| 50 | .B stat
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| 51 | structure into which information is placed concerning the file.
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| 52 | The contents of the structure pointed to by
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| 53 | .I buf
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| 54 | is as follows:
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| 55 | .PP
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| 56 | .if t .RS
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| 57 | .nf
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| 58 | .ta +0.4i +0.8i +1i
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| 59 | struct stat {
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| 60 | dev_t st_dev; /* device inode resides on */
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| 61 | ino_t st_ino; /* this inode's number */
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| 62 | mode_t st_mode; /* file mode, protection bits, etc. */
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| 63 | nlink_t st_nlink; /* number or hard links to the file */
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| 64 | uid_t st_uid; /* user-id of the file's owner */
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| 65 | gid_t st_gid; /* group-id of the file's owner */
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| 66 | dev_t st_rdev; /* the device type, for inode that is device */
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| 67 | off_t st_size; /* total size of file */
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| 68 | time_t st_atime; /* time of last access */
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| 69 | time_t st_mtime; /* time of last data modification */
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| 70 | time_t st_ctime; /* time of last file status change */
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| 71 | };
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| 72 | .fi
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| 73 | .if t .RE
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| 74 | .DT
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| 75 | .PP
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| 76 | .TP 12
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| 77 | st_atime
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| 78 | Time when file data was last read or modified. Changed by the following system
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| 79 | calls:
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| 80 | .BR mknod (2),
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| 81 | .BR utime (2),
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| 82 | .BR read (2),
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| 83 | and
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| 84 | .BR write (2).
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| 85 | For reasons of efficiency,
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| 86 | st_atime is not set when a directory
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| 87 | is searched, although this would be more logical.
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| 88 | .TP 12
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| 89 | st_mtime
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| 90 | Time when data was last modified.
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| 91 | It is not set by changes of owner, group, link count, or mode.
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| 92 | Changed by the following system calls:
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| 93 | .BR mknod (2),
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| 94 | .BR utime (2),
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| 95 | .BR write (2).
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| 96 | .TP 12
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| 97 | st_ctime
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| 98 | Time when file status was last changed.
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| 99 | It is set both both by writing and changing the i-node.
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| 100 | Changed by the following system calls:
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| 101 | .BR chmod (2)
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| 102 | .BR chown (2),
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| 103 | .BR link (2),
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| 104 | .BR mknod (2),
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| 105 | .BR rename (2),
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| 106 | .BR unlink (2),
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| 107 | .BR utime (2),
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| 108 | .BR write (2).
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| 109 | .PP
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| 110 | The file type information in \fBst_mode\fP has bits:
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| 111 | .PP
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| 112 | .nf
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| 113 | .in +5n
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| 114 | .ta 1.6i 2.5i 3i
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| 115 | #define S_IFMT 0170000 /* type of file */
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| 116 | #define\ \ \ \ S_IFIFO 0010000 /* named pipe */
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| 117 | #define\ \ \ \ S_IFCHR 0020000 /* character special */
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| 118 | #define\ \ \ \ S_IFDIR 0040000 /* directory */
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| 119 | #define\ \ \ \ S_IFBLK 0060000 /* block special */
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| 120 | #define\ \ \ \ S_IFREG 0100000 /* regular */
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| 121 | #define\ \ \ \ S_IFLNK 0120000 /* symbolic link */
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| 122 | .fi
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| 123 | .in -5n
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| 124 | .PP
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| 125 | The mode bits 0007777 encode set-uid/gid bits and
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| 126 | permission bits (see
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| 127 | .BR chmod (2)).
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| 128 | .SH "RETURN VALUE
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| 129 | Upon successful completion a value of 0 is returned.
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| 130 | Otherwise, a value of \-1 is returned and
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| 131 | .B errno
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| 132 | is set to indicate the error.
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| 133 | .SH "ERRORS
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| 134 | .B Stat
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| 135 | and
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| 136 | .B lstat
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| 137 | will fail if one or more of the following are true:
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| 138 | .TP 15
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| 139 | [ENOTDIR]
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| 140 | A component of the path prefix is not a directory.
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| 141 | .TP 15
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| 142 | [ENAMETOOLONG]
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| 143 | The path name exceeds PATH_MAX characters.
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| 144 | .TP 15
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| 145 | [ENOENT]
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| 146 | The named file does not exist.
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| 147 | .TP 15
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| 148 | [EACCES]
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| 149 | Search permission is denied for a component of the path prefix.
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| 150 | .TP 15
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| 151 | [ELOOP]
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| 152 | Too many symbolic links were encountered in translating the pathname.
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| 153 | .TP 15
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| 154 | [EFAULT]
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| 155 | .I Buf
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| 156 | or
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| 157 | .I name
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| 158 | points to an invalid address.
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| 159 | .TP 15
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| 160 | [EIO]
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| 161 | An I/O error occurred while reading from or writing to the file system.
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| 162 | .PP
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| 163 | .B Fstat
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| 164 | will fail if one or both of the following are true:
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| 165 | .TP 15
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| 166 | [EBADF]
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| 167 | .I Fildes
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| 168 | is not a valid open file descriptor.
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| 169 | .TP 15
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| 170 | [EFAULT]
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| 171 | .I Buf
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| 172 | points to an invalid address.
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| 173 | .TP 15
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| 174 | [EIO]
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| 175 | An I/O error occurred while reading from or writing to the file system.
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| 176 | .SH "SEE ALSO"
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| 177 | .BR chmod (2),
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| 178 | .BR chown (2),
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| 179 | .BR utime (2).
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