lber-types.3

OpenLdap是LDAP的开源项目

.TH LBER_TYPES 3 "RELEASEDATE" "OpenLDAP LDVERSION"
.\" $OpenLDAP: pkg/ldap/doc/man/man3/lber-types.3,v 1.16.2.4 2007/01/02 21:43:44 kurt Exp $
.\" Copyright 1998-2007 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
.SH NAME
ber_int_t, ber_uint_t, ber_len_t, ber_slen_t, ber_tag_t,
struct berval, BerValue, BerVarray, BerElement,
ber_bvfree, ber_bvecfree, ber_bvecadd, ber_bvarray_free, ber_bvarray_add,
ber_bvdup, ber_dupbv, ber_bvstr, ber_bvstrdup, ber_str2bv, ber_free
\- LBER types and allocation functions
.SH LIBRARY
OpenLDAP LBER (liblber, -llber)
.SH SYNOPSIS
.B #include <lber.h>
.LP
.nf
.ft B
typedef impl_tag_t ber_tag_t;
typedef impl_int_t ber_int_t;
typedef impl_uint_t ber_uint_t;
typedef impl_len_t ber_len_t;
typedef impl_slen_t ber_slen_t;

typedef struct berval {
    ber_len_t bv_len;
    char *bv_val;
} BerValue, *BerVarray;

typedef struct berelement BerElement;
.ft
.fi
.LP
.BI "void ber_bvfree(struct berval *" bv ");"
.LP
.BI "void ber_bvecfree(struct berval **" bvec ");"
.LP
.BI "void ber_bvecadd(struct berval ***" bvec ", struct berval *" bv ");"
.LP
.BI "void ber_bvarray_free(struct berval *" bvarray ");"
.LP
.BI "void ber_bvarray_add(BerVarray *" bvarray ", BerValue *" bv ");"
.LP
.BI "struct berval *ber_bvdup(const struct berval *" bv ");"
.LP
.BI "struct berval *ber_dupbv(const struct berval *" dst ", struct berval *" src ");"
.LP
.BI "struct berval *ber_bvstr(const char *" str ");"
.LP
.BI "struct berval *ber_bvstrdup(const char *" str ");"
.LP
.BI "struct berval *ber_str2bv(const char *" str ", ber_len_t " len ", int " dup ", struct berval *" bv ");"
.LP
.BI "void ber_free(BerElement *" ber ", int " freebuf ");"
.SH DESCRIPTION
.LP
The following are the basic types and structures defined for use
with the Lightweight BER library.  
.LP
.B ber_int_t
is a signed integer of at least 32 bits.  It is commonly equivalent to
.BR int .
.B ber_uint_t
is the unsigned variant of
.BR ber_int_t .
.LP
.B ber_len_t
is an unsigned integer of at least 32 bits used to represent a length.  
It is commonly equivalent to a
.BR size_t .
.B ber_slen_t
is the signed variant to
.BR ber_len_t .
.LP
.B ber_tag_t
is an unsigned integer of at least 32 bits used to represent a
BER tag.  It is commonly equivalent to a
.BR unsigned\ long .
.LP
The actual definitions of the integral impl_TYPE_t types are platform
specific.
.LP
.BR BerValue ,
commonly used as
.BR struct\ berval ,
is used to hold an arbitrary sequence of octets.
.B bv_val
points to
.B bv_len
octets.
.B bv_val
is not necessarily terminated by a NUL (zero) octet.
.BR ber_bvfree ()
frees a BerValue, pointed to by \fIbv\fP, returned from this API.  If \fIbv\fP
is NULL, the routine does nothing.
.LP
.BR ber_bvecfree ()
frees an array of BerValues (and the array), pointed to by \fIbvec\fP,
returned from this API.  If \fIbvec\fP is NULL, the routine does nothing.
.BR ber_bvecadd ()
appends the \fIbv\fP pointer to the \fIbvec\fP array.  Space for the array
is allocated as needed.  The end of the array is marked by a NULL pointer.
.LP
.BR ber_bvarray_free ()
frees an array of BerValues (and the array), pointed to by \fIbvarray\fP,
returned from this API.  If \fIbvarray\fP is NULL, the routine does nothing.
.BR ber_bvarray_add ()
appends the contents of the BerValue pointed to by \fIbv\fP to the
\fIbvarray\fP array.  Space for the new element is allocated as needed.
The end of the array is marked by a BerValue with a NULL bv_val field.
.LP
.BR ber_bvdup ()
returns a copy of a BerValue.  The routine returns NULL upon error
(e.g. out of memory).  The caller should use
.BR ber_bvfree ()
to deallocate the resulting BerValue.
.BR ber_dupbv ()
copies a BerValue from \fIsrc\fP to \fIdst\fP.  If \fIdst\fP is NULL a
new BerValue will be allocated to hold the copy.  The routine returns NULL
upon error, otherwise it returns a pointer to the copy.  If \fIdst\fP is
NULL the caller should use
.BR ber_bvfree ()
to deallocate the resulting BerValue, otherwise
.BR ber_memfree ()
should be used to deallocate the \fIdst->bv_val\fP.  (The
.BR ber_bvdup ()
function is internally implemented as ber_dupbv(NULL, bv).
.BR ber_bvdup ()
is provided only for compatibility with an expired draft of the LDAP C API;
.BR ber_dupbv ()
is the preferred interface.)
.LP
.BR ber_bvstr ()
returns a BerValue containing the string pointed to by \fIstr\fP.
.BR ber_bvstrdup ()
returns a BerValue containing a copy of the string pointed to by \fIstr\fP.
.BR ber_str2bv ()
returns a BerValue containing the string pointed to by \fIstr\fP, whose
length may be optionally specified in \fIlen\fP.  If \fIdup\fP is non-zero,
the BerValue will contain a copy of \fIstr\fP.  If \fIlen\fP is zero, the
number of bytes to copy will be determined by
.BR strlen (3),
otherwise \fIlen\fP bytes will be copied.  If \fIbv\fP is non-NULL, the result
will be stored in the given BerValue, otherwise a new BerValue will be
allocated to store the result.  NOTE: Both
.BR ber_bvstr ()
and
.BR ber_bvstrdup ()
are implemented as macros using
.BR ber_str2bv ()
in this version of the library.
.LP
.B BerElement
is an opaque structure used to maintain state information used in
encoding and decoding.  BerElement structures are created using
.BR ber_alloc_t (3)
and
.BR ber_init (3).
.BR ber_free ()
frees a BerElement pointed to by \fIber\fP.  If \fIber\fP is NULL, the routine
does nothing.  If \fIfreebuf\fP is zero, the internal buffer is not freed.
.SH SEE ALSO
.BR lber-encode (3),
.BR lber-decode (3),
.BR lber-memory (3)
.LP
.SH ACKNOWLEDGEMENTS
.B OpenLDAP
is developed and maintained by The OpenLDAP Project (http://www.openldap.org/).
.B OpenLDAP
is derived from University of Michigan LDAP 3.3 Release.