Returns true if the file is a character device, false if it isn’t or if the operating system doesn’t support this feature.
File.stat("/dev/tty").chardev? #=> true
Iterates over keys and objects in a weakly referenced object
Create an IO::Buffer for reading from file by memory-mapping the file. file_io should be a File instance, opened for reading.
Optional size and offset of mapping can be specified.
By default, the buffer would be immutable (read only); to create a writable mapping, you need to open a file in read-write mode, and explicitly pass flags argument without IO::Buffer::IMMUTABLE.
File.write('test.txt', 'test') buffer = IO::Buffer.map(File.open('test.txt'), nil, 0, IO::Buffer::READONLY) # => #<IO::Buffer 0x00000001014a0000+4 MAPPED READONLY> buffer.readonly? # => true buffer.get_string # => "test" buffer.set_string('b', 0) # `set_string': Buffer is not writable! (IO::Buffer::AccessError) # create read/write mapping: length 4 bytes, offset 0, flags 0 buffer = IO::Buffer.map(File.open('test.txt', 'r+'), 4, 0) buffer.set_string('b', 0) # => 1 # Check it File.read('test.txt') # => "best"
Note that some operating systems may not have cache coherency between mapped buffers and file reads.
If the buffer is mapped, meaning it references memory mapped by the buffer.
Mapped buffers are either anonymous, if created by ::new with the IO::Buffer::MAPPED flag or if the size was at least IO::Buffer::PAGE_SIZE, or backed by a file if created with ::map.
Mapped buffers can usually be resized, and such an operation will typically invalidate all slices, but not always.
Returns the path of this instruction sequence.
<compiled> if the iseq was evaluated from a string.
For example, using irb:
iseq = RubyVM::InstructionSequence.compile('num = 1 + 2') #=> <RubyVM::InstructionSequence:<compiled>@<compiled>> iseq.path #=> "<compiled>"
Using ::compile_file:
# /tmp/method.rb
def hello
puts "hello, world"
end
# in irb
> iseq = RubyVM::InstructionSequence.compile_file('/tmp/method.rb')
> iseq.path #=> /tmp/method.rb
Set path for which this cookie applies
Set domain for which this cookie applies
Store session data on the server. For some session storage types, this is a no-op.
Calls the block with each header-value pair; returns self:
source = "Name,Name,Name\nFoo,Bar,Baz\n" table = CSV.parse(source, headers: true) row = table[0] row.each {|header, value| p [header, value] }
Output:
["Name", "Foo"] ["Name", "Bar"] ["Name", "Baz"]
If no block is given, returns a new Enumerator:
row.each # => #<Enumerator: #<CSV::Row "Name":"Foo" "Name":"Bar" "Name":"Baz">:each>
Calls the block with each row or column; returns self.
When the access mode is :row or :col_or_row, calls the block with each CSV::Row object:
source = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" table = CSV.parse(source, headers: true) table.by_row! # => #<CSV::Table mode:row row_count:4> table.each {|row| p row }
Output:
#<CSV::Row "Name":"foo" "Value":"0"> #<CSV::Row "Name":"bar" "Value":"1"> #<CSV::Row "Name":"baz" "Value":"2">
When the access mode is :col, calls the block with each column as a 2-element array containing the header and an Array of column fields:
table.by_col! # => #<CSV::Table mode:col row_count:4> table.each {|column_data| p column_data }
Output:
["Name", ["foo", "bar", "baz"]] ["Value", ["0", "1", "2"]]
Returns a new Enumerator if no block is given:
table.each # => #<Enumerator: #<CSV::Table mode:col row_count:4>:each>
Returns the path from an FTP URI.
RFC 1738 specifically states that the path for an FTP URI does not include the / which separates the URI path from the URI host. Example:
ftp://ftp.example.com/pub/ruby
The above URI indicates that the client should connect to ftp.example.com then cd to pub/ruby from the initial login directory.
If you want to cd to an absolute directory, you must include an escaped / (%2F) in the path. Example:
ftp://ftp.example.com/%2Fpub/ruby
This method will then return “/pub/ruby”.
Produces the summary text. Each line of the summary is yielded to the block (without newline).
sdone
Already summarized short style options keyed hash.
ldone
Already summarized long style options keyed hash.
width
Width of left side (option part). In other words, the right side (description part) starts after width columns.
max
Maximum width of left side -> the options are filled within max columns.
indent
Prefix string indents all summarized lines.
Searches key in id list. The result is returned or yielded if a block is given. If it isn’t found, nil is returned.
Creates the summary table, passing each line to the block (without newline). The arguments args are passed along to the summarize method which is called on every option.