[Chapter 15] 15.10 Structure Conversion

15.10 Structure Conversion

pack template, list

Packs the values into a binary structure using template.

unpack template, expr

Unpacks the structure expr into an array, using template.

template is a sequence of characters as follows:

a / A ASCII string, null- / space-padded

b / B Bit string in ascending / descending order

c / C Native / unsigned char value

f / d Single / double float in native format

h / H Hex string, low / high nybble first.

i / I Signed / unsigned integer value

l / L Signed / unsigned long value

n / N Short / long in network (big endian) byte order

s / S Signed / unsigned short value

u / p Uuencoded string / pointer to a string

v / V Short / long in VAX (little endian) byte order

x / @ Null byte / null fill until position

X Backup a byte

Each character may be followed by a decimal number that will be used as a repeat count; an asterisk (*) specifies all remaining arguments. If the format is preceded with %n, unpack returns an n-bit checksum instead. Spaces may be included in the template for readability purposes.

a	/	A	ASCII string, null- / space-padded
b	/	B	Bit string in ascending / descending order
c	/	C	Native / unsigned char value
f	/	d	Single / double float in native format
h	/	H	Hex string, low / high nybble first.
i	/	I	Signed / unsigned integer value
l	/	L	Signed / unsigned long value
n	/	N	Short / long in network (big endian) byte order
s	/	S	Signed / unsigned short value
u	/	p	Uuencoded string / pointer to a string
v	/	V	Short / long in VAX (little endian) byte order
x	/	@	Null byte / null fill until position
X			Backup a byte


Conversion Functions		String Functions