Provided by: libsnmp-session-perl_1.14~git20130523.186a005-4_all bug

NAME

       BER - Basic Encoding Rules (BER) of Abstract Syntax Notation One (ASN.1)

SYNOPSIS

           use BER;
           $encoded = encode_sequence (encode_int (123), encode_string ("foo"));
           ($i, $s) = decode_by_template ($encoded, "%{%i%s");
           # $i will now be 123, $s the string "foo".

DESCRIPTION

       This is a simple library to encode and decode data using the Basic Encoding Rules (BER) of
       Abstract Syntax Notation One (ASN.1).  It does not claim to be a complete implementation
       of the standard, but implements enough of the BER standard to encode and decode SNMP
       messages.

VARIABLES

   $pretty_print_timeticks (default: 1)
       If non-zero (the default), "pretty_print" will convert TimeTicks to "human readable"
       strings containing days, hours, minutes and seconds.

       If the variable is zero, "pretty_print" will simply return an unsigned integer
       representing hundredths of seconds.  If you prefer this, bind $pretty_print_timeticks to
       zero.

   $errmsg - error message from last failed operation.
       When they encounter errors, the routines in this module will generally return "undef") and
       leave an informative error message in $errmsg).

METHODS

   encode_int_0() - encode the integer 0.
       This is functionally identical to encode_int(0).

   encode_int() - encode an integer using the generic "integer" type tag.
   encode_uinteger32() - encode an integer using the SNMP UInteger32 tag.
   encode_counter32() - encode an integer using the SNMP Counter32 tag.
   encode_counter64() - encode an integer using the SNMP Counter64 tag.
   encode_gauge32() - encode an integer using the SNMP Gauge32 tag.
   encode_oid() - encode an object ID, passed as a list of sub-IDs.
           $encoded = encode_oid (1,3,6,1,...);

   encode_null() - encode a null object.
       This is used e.g. in binding lists for variables that don't have a value (yet)

   encode_sequence()
   encode_tagged_sequence()
           $encoded = encode_sequence (encoded1, encoded2, ...);
           $encoded = encode_tagged_sequence (tag, encoded1, encoded2, ...);

       Take already encoded values, and extend them to an encoded sequence.  "encoded_sequence"
       uses the generic sequence tag, while with "encode_tagged_sequence" you can specify your
       own tag.

   encode_string() - encode a Perl string as an OCTET STRING.
   encode_ip_address() - encode an IPv4 address.
       This can either be passed as a four-octet sequence in network byte order, or as a text
       string in dotted-quad notation, e.g. "192.0.2.234".

   encode_timeticks() - encode an integer as a "TimeTicks" object.
       The integer should count hundredths of a second since the epoch defined by "sysUpTime.0".

   pretty_print() - convert an encoded byte sequence into human-readable form.
       This function can be extended by registering pretty-printing methods for specific type
       codes.  Most BER type codes used in SNMP already have such methods pre-registered by
       default.  See "register_pretty_printer" for how new methods can be added.

   hex_string() - convert OCTET STRING to hexadecimal notation.
   hex_string_of_type() - convert octet string to hex, and check type against given tag.
   decode_by_template() - decode complex object according to a template.
           ($var1, ...) = decode_by_template ($pdu, $template, ...);

       The template can contain various %X directives.  Some directives consume additional
       arguments following the template itself.  Most directives will cause values to be
       returned.  The values are returned as a sequence in the order of the directives that
       generated them.

       %{ - decode sequence.
           This doesn't assign any return value, just checks and skips the tag/length fields of
           the sequence.  By default, the tag should be the generic sequence tag, but a tag can
           also be specified in the directive.  The directive can either specify the tag as a
           prefix, e.g. "%99{" will require a sequence tag of 99, or if the directive is given as
           "%*{", the tag will be taken from the next argument.

       %s - decode string
       %i - decode integer
       %u - decode unsigned integer
       %O - decode Object ID (OID)
       %A - decode IPv4 address
       %@ - assigns the remaining undecoded part of the PDU to the next return value.

   decode_sequence() - Split sequence into components.
           ($first, $rest) = decode_sequence ($pdu);

       Checks whether the PDU has a sequence type tag and a plausible length field.  Splits the
       initial element off the list, and returns both this and the remainder of the PDU.

   register_pretty_printer() - register pretty-printing methods for typecodes.
       This function takes a hashref that specifies functions to call when the specified value
       type is being printed.  It returns the number of functions that were registered.

AUTHORS

       Created by:  Simon Leinen  <simon.leinen@switch.ch>

       Contributions and fixes by:

       Andrzej Tobola <san@iem.pw.edu.pl>:  Added long String decode
       Tobias Oetiker <tobi@oetiker.ch>:  Added 5 Byte Integer decode ...
       Dave Rand <dlr@Bungi.com>:  Added "SysUpTime" decode
       Philippe Simonet <sip00@vg.swissptt.ch>:  Support larger subids
       Yufang HU <yhu@casc.com>:  Support even larger subids
       Mike Mitchell <Mike.Mitchell@sas.com>: New generalized "encode_int()"
       Mike Diehn <mdiehn@mindspring.net>: "encode_ip_address()"
       Rik Hoorelbeke <rik.hoorelbeke@pandora.be>: "encode_oid()" fix
       Brett T Warden <wardenb@eluminant.com>: pretty "UInteger32"
       Bert Driehuis <driehuis@playbeing.org>: Handle SNMPv2 exception codes
       Jakob Ilves (/IlvJa) <jakob.ilves@oracle.com>: PDU decoding
       Jan Kasprzak <kas@informatics.muni.cz>: Fix for PDU syntax check
       Milen Pavlov <milen@batmbg.com>: Recognize variant length for ints

COPYRIGHT

       Copyright (c) 1995-2009, Simon Leinen.

       This program is free software; you can redistribute it under the "Artistic License 2.0"
       included in this distribution (file "Artistic").