Returns true if stat is a directory, false otherwise.
File.stat("testfile").directory? #=> false File.stat(".").directory? #=> true
Returns true if stat is readable by the effective user id of this process.
File.stat("testfile").readable? #=> true
If the buffer has 0 size: it is created by ::new with size 0, or with ::for from an empty string. (Note that empty files can’t be mapped, so the buffer created with ::map will never be empty.)
If the buffer is shared, meaning it references memory that can be shared with other processes (and thus might change without being modified locally).
# Create a test file: File.write('test.txt', 'test') # Create a shared mapping from the given file, the file must be opened in # read-write mode unless we also specify IO::Buffer::READONLY: buffer = IO::Buffer.map(File.open('test.txt', 'r+'), nil, 0) # => #<IO::Buffer 0x00007f1bffd5e000+4 EXTERNAL MAPPED SHARED> # Write to the buffer, which will modify the mapped file: buffer.set_string('b', 0) # => 1 # The file itself is modified: File.read('test.txt') # => "best"
Resizes a buffer to a new_size bytes, preserving its content. Depending on the old and new size, the memory area associated with the buffer might be either extended, or rellocated at different address with content being copied.
buffer = IO::Buffer.new(4) buffer.set_string("test", 0) buffer.resize(8) # resize to 8 bytes # => # #<IO::Buffer 0x0000555f5d1a1630+8 INTERNAL> # 0x00000000 74 65 73 74 00 00 00 00 test....
External buffer (created with ::for), and locked buffer can not be resized.
If the buffer references memory, release it back to the operating system.
for a mapped buffer (e.g. from file): unmap.
for a buffer created from scratch: free memory.
for a buffer created from string: undo the association.
After the buffer is freed, no further operations can’t be performed on it.
You can resize a freed buffer to re-allocate it.
buffer = IO::Buffer.for('test') buffer.free # => #<IO::Buffer 0x0000000000000000+0 NULL> buffer.get_value(:U8, 0) # in `get_value': The buffer is not allocated! (IO::Buffer::AllocationError) buffer.get_string # in `get_string': The buffer is not allocated! (IO::Buffer::AllocationError) buffer.null? # => true
Read at least length bytes from the io, into the buffer starting at offset. If an error occurs, return -errno.
If length is not given or nil, it defaults to the size of the buffer minus the offset, i.e. the entire buffer.
If length is zero, exactly one read operation will occur.
If offset is not given, it defaults to zero, i.e. the beginning of the buffer.
IO::Buffer.for('test') do |buffer| p buffer # => # <IO::Buffer 0x00007fca40087c38+4 SLICE> # 0x00000000 74 65 73 74 test buffer.read(File.open('/dev/urandom', 'rb'), 2) p buffer # => # <IO::Buffer 0x00007f3bc65f2a58+4 EXTERNAL SLICE> # 0x00000000 05 35 73 74 .5st end
Read at least length bytes from the io starting at the specified from position, into the buffer starting at offset. If an error occurs, return -errno.
If length is not given or nil, it defaults to the size of the buffer minus the offset, i.e. the entire buffer.
If length is zero, exactly one pread operation will occur.
If offset is not given, it defaults to zero, i.e. the beginning of the buffer.
IO::Buffer.for('test') do |buffer| p buffer # => # <IO::Buffer 0x00007fca40087c38+4 SLICE> # 0x00000000 74 65 73 74 test # take 2 bytes from the beginning of urandom, # put them in buffer starting from position 2 buffer.pread(File.open('/dev/urandom', 'rb'), 0, 2, 2) p buffer # => # <IO::Buffer 0x00007f3bc65f2a58+4 EXTERNAL SLICE> # 0x00000000 05 35 73 74 te.5 end
Returns the instruction sequence as a String in human readable form.
puts RubyVM::InstructionSequence.compile('1 + 2').disasm
Produces:
== disasm: <RubyVM::InstructionSequence:<compiled>@<compiled>>========== 0000 trace 1 ( 1) 0002 putobject 1 0004 putobject 2 0006 opt_plus <ic:1> 0008 leave
Takes body, a Method or Proc object, and returns a String with the human readable instructions for body.
For a Method object:
# /tmp/method.rb def hello puts "hello, world" end puts RubyVM::InstructionSequence.disasm(method(:hello))
Produces:
== disasm: <RubyVM::InstructionSequence:hello@/tmp/method.rb>============ 0000 trace 8 ( 1) 0002 trace 1 ( 2) 0004 putself 0005 putstring "hello, world" 0007 send :puts, 1, nil, 8, <ic:0> 0013 trace 16 ( 3) 0015 leave ( 2)
For a Proc:
# /tmp/proc.rb p = proc { num = 1 + 2 } puts RubyVM::InstructionSequence.disasm(p)
Produces:
== disasm: <RubyVM::InstructionSequence:block in <main>@/tmp/proc.rb>=== == catch table | catch type: redo st: 0000 ed: 0012 sp: 0000 cont: 0000 | catch type: next st: 0000 ed: 0012 sp: 0000 cont: 0012 |------------------------------------------------------------------------ local table (size: 2, argc: 0 [opts: 0, rest: -1, post: 0, block: -1] s1) [ 2] num 0000 trace 1 ( 1) 0002 putobject 1 0004 putobject 2 0006 opt_plus <ic:1> 0008 dup 0009 setlocal num, 0 0012 leave
Returns a new Tms object obtained by memberwise operation op of the individual times for this Tms object with those of the other Tms object (x).
op can be a mathematical operation such as +, -, *, /
Winds back to the beginning
Attempt to load the wrapped marshalled object again.
If the class of the object is now known locally, the object will be unmarshalled and returned. Otherwise, a new but identical DRbUnknown object will be returned.
Get the reference of the object, if local.
Set the default value of the :verbose option.
See new(). The initial default value is false.
Get the default value of the :verbose option.
Set whether to operate in verbose mode.
In verbose mode, failed calls are logged to stdout.
Get whether the server is in verbose mode.
In verbose mode, failed calls are logged to stdout.
Is this server alive?
Is uri the URI for this server?
Get the reference of the object, if local.