add missing modes
[unix-history] / usr / src / lib / libc / sys / chmod.2
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1.\" Copyright (c) 1980 Regents of the University of California.
2.\" All rights reserved. The Berkeley software License Agreement
3.\" specifies the terms and conditions for redistribution.
4.\"
3efa6125 5.\" @(#)chmod.2 6.1 (Berkeley) %G%
d149e2aa 6.\"
3efa6125 7.TH CHMOD 2 ""
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8.UC 4
9.SH NAME
10chmod \- change mode of file
11.SH SYNOPSIS
12.nf
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13.ft B
14chmod(path, mode)
15char *path;
16int mode;
17.PP
18.ft B
19fchmod(fd, mode)
20int fd, mode;
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21.fi
22.SH DESCRIPTION
23The file whose name
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24is given by \fIpath\fP
25or referenced by the descriptor
26.I fd
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27has its mode changed to
28.IR mode .
29Modes are constructed by
7656e522 30.IR or 'ing
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31together some
32combination of the following:
33.PP
34.RS
35 04000 set user ID on execution
36 02000 set group ID on execution
37 01000 save text image after execution
38 00400 read by owner
39 00200 write by owner
40 00100 execute (search on directory) by owner
41 00070 read, write, execute (search) by group
42 00007 read, write, execute (search) by others
43.RE
44.PP
45If an executable file is set up for sharing (this is the default)
46then mode 1000 prevents the system from
47abandoning the swap-space image of the program-text portion
48of the file when its last user
49terminates.
7656e522 50Ability to set this bit is restricted to the super-user.
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51.PP
52Only the owner of a file (or the super-user) may change the mode.
d149e2aa 53.PP
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54Writing or changing the owner of a file
55turns off the set-user-id and set-group-id bits.
d149e2aa 56This makes the system somewhat more secure
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57by protecting set-user-id (set-group-id) files
58from remaining set-user-id (set-group-id) if they are modified,
d149e2aa 59at the expense of a degree of compatibility.
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60.SH "RETURN VALUE
61Upon successful completion, a value of 0 is returned.
62Otherwise, a value of \-1 is returned and
63.I errno
64is set to indicate the error.
65.SH "ERRORS
66.I Chmod
67will fail and the file mode will be unchanged if:
68.TP 15
69[EPERM]
70The argument contains a byte with the high-order bit set.
71.TP 15
72[ENOTDIR]
73A component of the path prefix is not a directory.
74.TP 15
75[ENOENT]
76The pathname was too long.
77.TP 15
78[ENOENT]
79The named file does not exist.
80.TP 15
81[EACCES]
82Search permission is denied on a component of the path prefix.
83.TP 15
84[EPERM]
85The effective user ID does not match the owner of the file and
86the effective user ID is not the super-user.
87.TP 15
88[EROFS]
89The named file resides on a read-only file system.
90.TP 15
91[EFAULT]
92.I Path
93points outside the process's allocated address space.
94.TP 15
95[ELOOP]
96Too many symbolic links were encountered in translating the pathname.
97.PP
98.I Fchmod
99will fail if:
100.TP 15
101[EBADF]
102The descriptor is not valid.
103.TP 15
104[EINVAL]
105.I Fd
106refers to a socket, not to a file.
107.TP 15
108[EROFS]
109The file resides on a read-only file system.
d149e2aa 110.SH "SEE ALSO"
7656e522 111open(2), chown(2)