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 *

# File 'pack.c', line 440

static VALUE
pack_pack(ary, fmt)
VALUE ary, fmt;