strmode - convert inode status information into a symbolic string
Standard C Library (libc, -lc)
#include <unistd.h>
void
strmode(mode_t mode, char *bp);
The strmode() function converts a file mode (the type and permission
information associated with an inode, see stat(2)) into a symbolic string
which is stored in the location referenced by bp. This stored string is
eleven characters in length plus a trailing NULL.
The first character is the inode type, and will be one of the following:
- regular file
a regular file in archive state 1
A regular file in archive state 2
b block special
c character special
d directory
l symbolic link
p fifo
s socket
w whiteout
? unknown inode type
The next nine characters encode three sets of permissions, in three characters
each. The first three characters are the permissions for the
owner of the file, the second three for the group the file belongs to,
and the third for the ``other'', or default, set of users.
Permission checking is done as specifically as possible. If read permission
is denied to the owner of a file in the first set of permissions,
the owner of the file will not be able to read the file. This is true
even if the owner is in the file's group and the group permissions allow
reading or the ``other'' permissions allow reading.
If the first character of the three character set is an ``r'', the file
is readable for that set of users; if a dash ``-'', it is not readable.
If the second character of the three character set is a ``w'', the file
is writable for that set of users; if a dash ``-'', it is not writable.
The third character is the first of the following characters that apply:
S If the character is part of the owner permissions and the file is
not executable or the directory is not searchable by the owner, and
the set-user-id bit is set.
S If the character is part of the group permissions and the file is
not executable or the directory is not searchable by the group, and
the set-group-id bit is set.
T If the character is part of the other permissions and the file is
not executable or the directory is not searchable by others, and
the ``sticky'' (S_ISVTX) bit is set.
s If the character is part of the owner permissions and the file is
executable or the directory searchable by the owner, and the setuser-id
bit is set.
s If the character is part of the group permissions and the file is
executable or the directory searchable by the group, and the setgroup-id
bit is set.
t If the character is part of the other permissions and the file is
executable or the directory searchable by others, and the
``sticky'' (S_ISVTX) bit is set.
x The file is executable or the directory is searchable.
- None of the above apply.
The last character is a plus sign ``+'' if there are any alternative or
additional access control methods associated with the inode, otherwise it
will be a space.
Archive state 1 and archive state 2 represent file system dependent
archive state for a file. Most file systems do not retain file archive
state, and so will not report files in either archive state. msdosfs
will report a file in archive state 1 if it has been archived more
recently than modified. Hierarchical storage systems may have multiple
archive states for a file and may define archive states 1 and 2 as appropriate.
chmod(1), find(1), stat(2), getmode(3), setmode(3)
The strmode() function first appeared in 4.4BSD.
BSD July 28, 1994 BSD
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