xref: /openbsd/lib/libc/string/strmode.3 (revision 73471bf0)
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30.\"     @(#)strmode.3	8.3 (Berkeley) 7/28/94
31.\"
32.Dd $Mdocdate: July 5 2017 $
33.Dt STRMODE 3
34.Os
35.Sh NAME
36.Nm strmode
37.Nd convert inode status information into a symbolic string
38.Sh SYNOPSIS
39.In string.h
40.Ft void
41.Fn strmode "mode_t mode" "char *bp"
42.Sh DESCRIPTION
43The
44.Fn strmode
45function converts a file
46.Fa mode
47(the type and permission information associated with an inode, see
48.Xr stat 2 )
49into a symbolic string which is stored in the location referenced by
50.Fa bp .
51This stored string is eleven characters in length plus a trailing NUL byte.
52.Pp
53The first character is the inode type, and will be one of the following:
54.Pp
55.Bl -tag -width flag -offset indent -compact
56.It \-
57regular file
58.It b
59block special
60.It c
61character special
62.It d
63directory
64.It l
65symbolic link
66.It p
67FIFO
68.It s
69socket
70.It \&?
71unknown inode type
72.El
73.Pp
74The next nine characters encode three sets of permissions, in three
75characters each.
76The first three characters are the permissions for the owner of the
77file, the second three for the group the file belongs to, and the
78third for the
79.Dq other ,
80or default, set of users.
81.Pp
82Permission checking is done as specifically as possible.
83If read permission is denied to the owner of a file in the first set
84of permissions, the owner of the file will not be able to read the file.
85This is true even if the owner is in the file's group and the group
86permissions allow reading or the
87.Dq other
88permissions allow reading.
89.Pp
90If the first character of the three character set is an
91.Sq r ,
92the file is readable for that set of users; if a dash
93.Pq Ql - ,
94it is not readable.
95.Pp
96If the second character of the three character set is a
97.Sq w ,
98the file is writable for that set of users; if a dash
99.Pq Ql - ,
100it is not writable.
101.Pp
102The third character is the first of the following characters that apply:
103.Bl -tag -width xxxx
104.It S
105If the character is part of the owner permissions and the file is not
106executable or the directory is not searchable by the owner, and the
107set-user-ID bit is set.
108.It S
109If the character is part of the group permissions and the file is not
110executable or the directory is not searchable by the group, and the
111set-group-ID bit is set.
112.It T
113If the character is part of the other permissions and the file is not
114executable or the directory is not searchable by others, and the
115.Dq sticky
116.Pq Dv S_ISVTX
117bit is set.
118.It s
119If the character is part of the owner permissions and the file is
120executable or the directory searchable by the owner, and the set-user-ID
121bit is set.
122.It s
123If the character is part of the group permissions and the file is
124executable or the directory searchable by the group, and the set-group-ID
125bit is set.
126.It t
127If the character is part of the other permissions and the file is
128executable or the directory searchable by others, and the
129.Dq sticky
130.Pq Dv S_ISVTX
131bit is set.
132.It x
133The file is executable or the directory is searchable.
134.It \-
135None of the above apply.
136.El
137.Pp
138The last character is a plus sign
139.Pq Ql +
140if there are any alternate
141or additional access control methods associated with the inode, otherwise
142it will be a space.
143.Sh SEE ALSO
144.Xr chmod 1 ,
145.Xr find 1 ,
146.Xr stat 2 ,
147.Xr getmode 3 ,
148.Xr setmode 3
149.Sh HISTORY
150The
151.Fn strmode
152function first appeared in
153.Bx 4.3 Reno .
154