The following methods are duplicates, but it is faster than using a helper
Sets the process title that appears on the ps(1) command. Not necessarily effective on all platforms. No exception will be raised regardless of the result, nor will NotImplementedError
be raised even if the platform does not support the feature.
Calling this method does not affect the value of $0.
Process.setproctitle('myapp: worker #%d' % worker_id)
This method first appeared in Ruby 2.1 to serve as a global variable free means to change the process title.
Stop tracing object allocations.
Note that if ::trace_object_allocations_start
is called n-times, then tracing will stop after calling ::trace_object_allocations_stop
n-times.
Returns the number of online processors.
The result is intended as the number of processes to use all available processors.
This method is implemented using:
sched_getaffinity(): Linux
sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX
Example:
require 'etc' p Etc.nprocessors #=> 4
The result might be smaller number than physical cpus especially when ruby process is bound to specific cpus. This is intended for getting better parallel processing.
Example: (Linux)
linux$ taskset 0x3 ./ruby -retc -e "p Etc.nprocessors" #=> 2
Gets the scheduling priority for specified process, process group, or user. kind indicates the kind of entity to find: one of Process::PRIO_PGRP
, Process::PRIO_USER
, or Process::PRIO_PROCESS
. integer is an id indicating the particular process, process group, or user (an id of 0 means current). Lower priorities are more favorable for scheduling. Not available on all platforms.
Process.getpriority(Process::PRIO_USER, 0) #=> 19 Process.getpriority(Process::PRIO_PROCESS, 0) #=> 19
See Process.getpriority
.
Process.setpriority(Process::PRIO_USER, 0, 19) #=> 0 Process.setpriority(Process::PRIO_PROCESS, 0, 19) #=> 0 Process.getpriority(Process::PRIO_USER, 0) #=> 19 Process.getpriority(Process::PRIO_PROCESS, 0) #=> 19
Initializes the supplemental group access list by reading the system group database and using all groups of which the given user is a member. The group with the specified gid is also added to the list. Returns the resulting Array
of the gids of all the groups in the supplementary group access list. Not available on all platforms.
Process.groups #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27] Process.initgroups( "mgranger", 30 ) #=> [30, 6, 10, 11] Process.groups #=> [30, 6, 10, 11]
Get an Array
of the group IDs in the supplemental group access list for this process.
Process.groups #=> [27, 6, 10, 11]
Note that this method is just a wrapper of getgroups(2). This means that the following characteristics of the result completely depend on your system:
the result is sorted
the result includes effective GIDs
the result does not include duplicated GIDs
You can make sure to get a sorted unique GID
list of the current process by this expression:
Process.groups.uniq.sort
Set
the supplemental group access list to the given Array
of group IDs.
Process.groups #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27] Process.groups = [27, 6, 10, 11] #=> [27, 6, 10, 11] Process.groups #=> [27, 6, 10, 11]
Returns the maximum number of gids allowed in the supplemental group access list.
Process.maxgroups #=> 32
Sets the maximum number of gids allowed in the supplemental group access list.
Returns the cross product of this vector with the others.
Vector[1, 0, 0].cross_product Vector[0, 1, 0] => Vector[0, 0, 1]
It is generalized to other dimensions to return a vector perpendicular to the arguments.
Vector[1, 2].cross_product # => Vector[-2, 1] Vector[1, 0, 0, 0].cross_product( Vector[0, 1, 0, 0], Vector[0, 0, 1, 0] ) #=> Vector[0, 0, 0, 1]
Returns an array of all combinations of elements from all arrays.
The length of the returned array is the product of the length of self
and the argument arrays.
If given a block, product
will yield all combinations and return self
instead.
[1,2,3].product([4,5]) #=> [[1,4],[1,5],[2,4],[2,5],[3,4],[3,5]] [1,2].product([1,2]) #=> [[1,1],[1,2],[2,1],[2,2]] [1,2].product([3,4],[5,6]) #=> [[1,3,5],[1,3,6],[1,4,5],[1,4,6], # [2,3,5],[2,3,6],[2,4,5],[2,4,6]] [1,2].product() #=> [[1],[2]] [1,2].product([]) #=> []
Creates an infinite enumerator from any block, just called over and over. The result of the previous iteration is passed to the next one. If initial
is provided, it is passed to the first iteration, and becomes the first element of the enumerator; if it is not provided, the first iteration receives nil
, and its result becomes the first element of the iterator.
Raising StopIteration
from the block stops an iteration.
Enumerator.produce(1, &:succ) # => enumerator of 1, 2, 3, 4, .... Enumerator.produce { rand(10) } # => infinite random number sequence ancestors = Enumerator.produce(node) { |prev| node = prev.parent or raise StopIteration } enclosing_section = ancestors.find { |n| n.type == :section }
Using ::produce
together with Enumerable
methods like Enumerable#detect
, Enumerable#slice, Enumerable#take_while
can provide Enumerator-based alternatives for while
and until
cycles:
# Find next Tuesday require "date" Enumerator.produce(Date.today, &:succ).detect(&:tuesday?) # Simple lexer: require "strscan" scanner = StringScanner.new("7+38/6") PATTERN = %r{\d+|[-/+*]} Enumerator.produce { scanner.scan(PATTERN) }.slice_after { scanner.eos? }.first # => ["7", "+", "38", "/", "6"]
With no arguments, sets the default visibility for subsequently defined methods to protected. With arguments, sets the named methods to have protected visibility. String
arguments are converted to symbols.
If a method has protected visibility, it is callable only where self
of the context is the same as the method. (method definition or instance_eval). This behavior is different from Java’s protected method. Usually private
should be used.
Note that a protected method is slow because it can’t use inline cache.
To show a private method on RDoc
, use :doc:
instead of this.
Runs the early binding method to get property. The 1st argument specifies dispatch ID, the 2nd argument specifies the array of arguments, the 3rd argument specifies the array of the type of arguments.
excel = WIN32OLE.new('Excel.Application') puts excel._getproperty(558, [], []) # same effect as puts excel.visible
Runs the early binding method to set property. The 1st argument specifies dispatch ID, the 2nd argument specifies the array of arguments, the 3rd argument specifies the array of the type of arguments.
excel = WIN32OLE.new('Excel.Application') excel._setproperty(558, [true], [WIN32OLE::VARIANT::VT_BOOL]) # same effect as excel.visible = true
Sets property of OLE object. When you want to set property with argument, you can use this method.
excel = WIN32OLE.new('Excel.Application') excel.Visible = true book = excel.workbooks.add sheet = book.worksheets(1) sheet.setproperty('Cells', 1, 2, 10) # => The B1 cell value is 10.
Returns array of ProgID.