.TH LABTOA 3
.SH NAME
labtoa, atolab, atopriv, privtoa \- security label conversion
.SH SYNOPSIS
.B #include <sys/label.h>
.PP
.B char *labtoa(labp)
.B struct label *labp;
.br
.B struct label *atolab(string)
.B char *string;
.PP
.B  atopriv(string)
.B char *string;
.PP
.B char *privtoa(n)
.SH DESCRIPTION
.I Labtoa
returns a pointer to a null-terminated
.SM ASCII
string that represents
the value of the security label pointed to by 
.I labp.
The string has a form exemplified by
.IP
.B "guxnlp guxnlpFY 0000 0000 ...
.LP
The characters of the first group
.L guxnlp
denote capabilities
.BR T_LOG ,
.BR T_UAREA ,
.BR T_EXTERN ,
.BR T_NOCHK ,
.BR T_SETLIC ,
and
.BR T_SETPRIV
respectively.
Characters of the second group denote corresponding licenses; see
.IR getplab (2).
Missing capabilities or licenses are denoted by
.LR - .
.PP
The character shown as 
.L F
denotes the fixity of the label.
It may be a space (loose),
.L F
(frozen),
.L R
(rigid),
or
.L C
(constant)
The character shown as 
.L Y
denotes the label's flag.
It may be a space for a lattice label,
.L N
for
.BR L_NO ,
.L Y
for
.BR L_YES ,
or
.L U
for the erroneous flag value 0.
.PP
Each group of four zeros may be any four lower case hex digits 
representing the value of two bytes of the lattice value.
Repeating groups at the end of the string are denoted
.LR ... .
.LP
.I Atolab
inverts the process.
The order of characters in, and length of, privilege strings are
arbitrary, except that a nonempty license string must be
preceded by a nonempty capability string.
The order of characters from the set
.B YNUFRC
is arbitrary.
Spaces must separate nonempty capability and license strings,
and may be interspersed arbitrarily after the license string.
A final
.B ...
causes the last four hex digits 
to be repeated, provided the preceding label contains
a multiple of four digits.
A short or missing lattice value is padded with zeros.
.PP
.I Atopriv
converts a string of characters from the set
.L guxnlp-
into privilege bits that may be stored in the
.B lb_t
or
.B lb_u
fields of a label structure.
The order and number of characters are arbitrary.
.PP
.I Privtoa
is inverse to
.I atopriv.
.SH SEE ALSO
.IR getflab (2),
.IR getplab (2),
.IR getlab (1)
.SH DIAGNOSTICS
.I Atolab
returns 0 for unrecognizable input.
.PP
.I Atopriv
returns the negative value 
.B ~(T_LOG|T_UAREA|T_EXTERN|T_NOCHK|T_SETLIC|T_SETPRIV)
for unrecognizable input.
.SH BUGS
The value returned by
.I labtoa,
.I atolab,
or
.I privtoa
points to a static buffer that is overwritten
at each call.