ycstruct

Just like Python's struct module, pack/unpack values to/from buffer.

Format String

First charactor can be endian charactor, it can also be omited(default is Big Endian).

>    Big Endian  
<    Little Endian

The following charactor can be:

b    signed int8
B    unsigned int8
h    signed int16
H    unsigned int16
i    signed int32
I    unsigned int32
f    float
d    double
s    string (utf8)
R    buffer

Format charactor can has a number prefix:

• for string and buffer, it's the length of value
• for other format charactor, it's the count of value

When pack/unpack string, only "utf8" encoding is supported, if you want to use other encoding, try to convert them to Buffer.

• before pack: s = new Buffer(s, 'binary')
• after unpack: s = s.toString('binary')

API

Struct(format, fill = 0x00) pack(...) unpack(buff)

Usage

Struct = require('ycstruct')

# pack numbers
st = new Struct('>BHI')
buff = st.pack(12, 1234, 123456)

results = st.unpack(buff)
results[0] == 12
results[1] == 1234
results[2] == 123456

# number prefix
st = new Struct('>3H')
st.pack(1234, 1234, 1234)

# pack string
st = new Struct('12s5s', 0x00)
buff = st.pack('hello', 'world')

ChangeLog

0.1.1

• BUGFIX: readUInt16 is undefined, should be readUInt16BE/readUInt16LE

0.1.0

• remove encoding argument from Struct#constructor, only "utf8" string is supported
• buffer format char changed from "=" to "R"
• allow space in format string, and space is ignore

0.0.1

• initialize version