--- Pack and unpack binary data. -- -- A problem script authors often face is the necessity of encoding values -- into binary data. For example after analyzing a protocol the starting -- point to write a script could be a hex dump, which serves as a preamble -- to every sent packet. Although it is possible to work with the -- functionality Lua provides, it's not very convenient. Therefore NSE includes -- Binlib, based on lpack (http://www.tecgraf.puc-rio.br/~lhf/ftp/lua/) -- by Luiz Henrique de Figueiredo. -- -- The Binlib functions take a format string to encode and decode binary -- data. Packing and unpacking are controlled by the following operator -- characters: -- * H hex string -- * B bit string -- * x null byte -- * z zero-terminated string -- * p string preceded by 1-byte integer length -- * P string preceded by 2-byte integer length -- * a string preceded by 4-byte integer length -- * A string -- * f float -- * d double -- * n Lua number -- * c char (1-byte integer) -- * C byte = unsigned char (1-byte unsigned integer) -- * s short (2-byte integer) -- * S unsigned short (2-byte unsigned integer) -- * i int (4-byte integer) -- * I unsigned int (4-byte unsigned integer) -- * l long (8-byte integer) -- * L unsigned long (8-byte unsigned integer) -- * < little endian modifier -- * > big endian modifier -- * = native endian modifier -- -- Note that the endian operators work as modifiers to all the -- characters following them in the format string. module "bin" --- Returns a binary packed string. -- -- The format string describes how the parameters (p1, -- ...) will be interpreted. Numerical values following operators -- stand for operator repetitions and need an according amount of parameters. -- Operators expect appropriate parameter types. -- -- Note: on Windows packing of 64-bit values > 2^63 currently -- results in packing exactly 2^63. -- @param format Format string, used to pack following arguments. -- @param ... The values to pack. -- @return String containing packed data. function pack(format, ...) --- Returns values read from the binary packed data string. -- -- The first return value of this function is the position at which unpacking -- stopped. This can be used as the init value for subsequent -- calls. The following return values are the values according to the format -- string. Numerical values in the format string are interpreted as repetitions -- like in pack, except if used with A, -- B, or H, in which cases the number tells -- unpack how many bytes to read. unpack stops if -- either the format string or the binary data string are exhausted. -- @param format Format string, used to unpack values out of data string. -- @param data String containing packed data. -- @param init Optional starting position within the string. -- @return Position in the data string where unpacking stopped. -- @return All unpacked values. function unpack(format, data, init)