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instance method

String#unpack

(::string template, ?offset: ::int) -> ::Array[::Integer | ::Float | ::String | nil]

(::string template, ?offset: ::int) { (::Integer | ::Float | ::String | nil value) -> void } -> nil

unpack(template, offset: 0) {|o| .... } → object

unpack(template, offset: 0) → array

# File tmp/rubies/ruby-4.1.0-preview1/pack.rb, line 25
def unpack(fmt, offset: 0)
  Primitive.attr! :use_block
  Primitive.pack_unpack(fmt, offset)
end

Extracts data from self to form new objects; see Packed Data.

With a block given, calls the block with each unpacked object.

With no block given, returns an array containing the unpacked objects.

Related: see Converting to Non-String.

Ruby version changes

4.1
- String#unpack and String#unpack1 accept new formats R and r for unsigned and signed LEB128 encoded integers. [Feature #21785]
- String#unpack and String#unpack1 accept a new format ^ that returns the current offset. Useful when combined with variable width formats like LEB128. [Feature #21796]
- String#unpack and String#unpack1 accept new formats x! and @! to align the current offset to a byte boundary or to the ABI alignment of another directive. [Feature #22185]
3.3
- String#unpack now raises ArgumentError for unknown directives. [Bug #19150]
3.1
- String#unpack and String#unpack1 now accept an offset: keyword argument to start the unpacking after an arbitrary number of bytes have been skipped. If offset is outside of the string bounds ArgumentError is raised. [Feature #18254]

See also #unicode_normalized? #unpack1 #unicode_normalize! #upcase also in 4.0 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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