Method: Array#pack
- Defined in:
- pack.c
#pack ⇒ Object
Packs the contents of arr into a binary sequence according to the directives in aTemplateString (see the table below) Directives “A,” “a,” and “Z” may be followed by a count, which gives the width of the resulting field. The remaining directives also may take a count, indicating the number of array elements to convert. If the count is an asterisk (“*
”), all remaining array elements will be converted. Any of the directives “sSiIlL
” may be followed by an underscore (“_
”) to use the underlying platform’s native size for the specified type; otherwise, they use a platform-independent size. Spaces are ignored in the template string. See also String#unpack
.
a = [ "a", "b", "c" ]
n = [ 65, 66, 67 ]
a.pack("A3A3A3") #=> "a b c "
a.pack("a3a3a3") #=> "a\000\000b\000\000c\000\000"
n.pack("ccc") #=> "ABC"
Directives for pack
.
Directive Meaning
---------------------------------------------------------------
@ | Moves to absolute position
A | ASCII string (space padded, count is width)
a | ASCII string (null padded, count is width)
B | Bit string (descending bit order)
b | Bit string (ascending bit order)
C | Unsigned char
c | Char
D, d | Double-precision float, native format
E | Double-precision float, little-endian byte order
e | Single-precision float, little-endian byte order
F, f | Single-precision float, native format
G | Double-precision float, network (big-endian) byte order
g | Single-precision float, network (big-endian) byte order
H | Hex string (high nibble first)
h | Hex string (low nibble first)
I | Unsigned integer
i | Integer
L | Unsigned long
l | Long
M | Quoted printable, MIME encoding (see RFC2045)
m | Base64 encoded string
N | Long, network (big-endian) byte order
n | Short, network (big-endian) byte-order
P | Pointer to a structure (fixed-length string)
p | Pointer to a null-terminated string
Q, q | 64-bit number
S | Unsigned short
s | Short
U | UTF-8
u | UU-encoded string
V | Long, little-endian byte order
v | Short, little-endian byte order
w | BER-compressed integer\fnm
X | Back up a byte
x | Null byte
Z | Same as ``a'', except that null is added with *
440 441 442 |
# File 'pack.c', line 440 static VALUE pack_pack(ary, fmt) VALUE ary, fmt; |