Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native).
Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native).
Returns the execution stack for the target thread—an array containing backtrace location objects.
See Thread::Backtrace::Location
for more information.
This method behaves similarly to Kernel#caller_locations
except it applies to a specific thread.
Converts block to a Proc
object (and therefore binds it at the point of call) and registers it for execution when the program exits. If multiple handlers are registered, they are executed in reverse order of registration.
def do_at_exit(str1) at_exit { print str1 } end at_exit { puts "cruel world" } do_at_exit("goodbye ") exit
produces:
goodbye cruel world
Ruby tries to load the library named string relative to the requiring file’s path. If the file’s path cannot be determined a LoadError
is raised. If a file is loaded true
is returned and false otherwise.
Returns the current execution stack—an array containing backtrace location objects.
See Thread::Backtrace::Location
for more information.
The optional start parameter determines the number of initial stack entries to omit from the top of the stack.
A second optional length
parameter can be used to limit how many entries are returned from the stack.
Returns nil
if start is greater than the size of current execution stack.
Optionally you can pass a range, which will return an array containing the entries within the specified range.
Returns a new array with the concatenated results of running block once for every element in enum.
If no block is given, an enumerator is returned instead.
[1, 2, 3, 4].flat_map { |e| [e, -e] } #=> [1, -1, 2, -2, 3, -3, 4, -4] [[1, 2], [3, 4]].flat_map { |e| e + [100] } #=> [1, 2, 100, 3, 4, 100]
Returns a new array with the concatenated results of running block once for every element in enum.
If no block is given, an enumerator is returned instead.
[1, 2, 3, 4].flat_map { |e| [e, -e] } #=> [1, -1, 2, -2, 3, -3, 4, -4] [[1, 2], [3, 4]].flat_map { |e| e + [100] } #=> [1, 2, 100, 3, 4, 100]
Passes elements to the block until the block returns nil
or false
, then stops iterating and returns an array of all prior elements.
If no block is given, an enumerator is returned instead.
a = [1, 2, 3, 4, 5, 0] a.take_while { |i| i < 3 } #=> [1, 2]
Generate a JSON
document from the Ruby data structure obj and return it. This method disables the checks for circles in Ruby objects.
WARNING: Be careful not to pass any Ruby data structures with circles as obj argument because this will cause JSON
to go into an infinite loop.
Generate a JSON
document from the Ruby data structure obj and return it. The returned document is a prettier form of the document returned by unparse.
The opts argument can be used to configure the generator. See the generate method for a more detailed explanation.
Returns the source file origin from the given object
.
See ::trace_object_allocations
for more information and examples.
Returns the original line from source for from the given object
.
See ::trace_object_allocations
for more information and examples.
Returns the table for calculating CRC checksum as an array.
Returns true
if the named file is readable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not readable by the real user/group.
If file_name is readable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_readable?("/etc/passwd") #=> 420 m = File.world_readable?("/etc/passwd") sprintf("%o", m) #=> "644"
Returns true
if the named file is writable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.
If file_name is writable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_writable?("/tmp") #=> 511 m = File.world_writable?("/tmp") sprintf("%o", m) #=> "777"
Returns true
if the named file is executable by the real user and group id of this process. See access(3).
Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.
Note that some OS-level security features may cause this to return true even though the file is not executable by the real user/group.
Returns the number of malloc() allocations.
Only available if ruby was built with CALC_EXACT_MALLOC_SIZE
.
Try to activate a gem containing path
. Returns true if activation succeeded or wasn’t needed because it was already activated. Returns false if it can’t find the path in a gem.
Find
the full path to the executable for gem name
. If the exec_name
is not given, an exception will be raised, otherwise the specified executable’s path is returned. requirements
allows you to specify specific gem versions.
Reset the dir
and path
values. The next time dir
or path
is requested, the values will be calculated from scratch. This is mainly used by the unit tests to provide test isolation.
Adds a post-install hook that will be passed an Gem::Installer
instance when Gem::Installer#install
is called
Adds a post-installs hook that will be passed a Gem::DependencyInstaller
and a list of installed specifications when Gem::DependencyInstaller#install
is complete