.TH LIBRECRYPT_SETTINGS_PREFIX 3 LIBRECRYPT
.SH NAME
librecrypt_settings_prefix - Get length of settings prefix in a password hash string

.SH SYNOPSIS
.nf
#include <librecrypt.h>

size_t \fBlibrecrypt_settings_prefix\fP(const char *\fIhash\fP);
.fi
.PP
Link with
.IR -lrecrypt .

.SH DESCRIPTION
The
.BR librecrypt_settings_prefix ()
function returns the number of bytes, from the front of
.IR hash ,
that make up the algorithm configuration.
.PP
The string is scanned for the delimiters
.I LIBRECRYPT_HASH_COMPOSITION_DELIMITER
(which is
.BR \(aq$\(aq )
and
.I LIBRECRYPT_ALGORITHM_LINK_DELIMITER
(which is
.BR \(aq>\(aq ),
and the returned value is one byte past the
last occurrence, or 0 if none was found.
.PP
.I hash
must not be
.IR NULL .

.SH RETURN VALUES
The
.BR librecrypt_settings_prefix ()
function returns the number of bytes that make up the
settings prefix. The return value may be 0, which shall
be treated as any other valid return value.
.PP
.IR &hash[r] ,
where
.I r
is the return value, points to the hash result proper.

.SH ERRORS
The
.BR librecrypt_settings_prefix ()
function cannot fail.

.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.PP
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR librecrypt_settings_prefix ()
T}	Thread safety	MT-Safe
T{
.BR librecrypt_settings_prefix ()
T}	Async-signal safety	AS-Safe
.TE
.sp

.SH HISTORY
The
.BR librecrypt_settings_prefix ()
function was introduced in version 1.0 of
.BR librecrypt .

.SH SEE ALSO
.BR librecrypt (7),
.BR librecrypt_chain_length (3)