Ends the process of scanning through the /etc/group file begun by ::getgrent, and closes the file.
Returns an entry from the /etc/group file.
The first time it is called it opens the file and returns the first entry; each successive call returns the next entry, or nil if the end of the file has been reached.
To close the file when processing is complete, call ::endgrent.
Each entry is returned as a Group struct
Returns system temporary directory; typically “/tmp”.
Returns system configuration variable using confstr().
name should be a constant under Etc which begins with CS_.
The return value is a string or nil. nil means no configuration-defined value. (confstr() returns 0 but errno is not set.)
Etc.confstr(Etc::CS_PATH) #=> "/bin:/usr/bin" # GNU/Linux Etc.confstr(Etc::CS_GNU_LIBC_VERSION) #=> "glibc 2.18" Etc.confstr(Etc::CS_GNU_LIBPTHREAD_VERSION) #=> "NPTL 2.18"
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
Change the size of the memory allocated at the memory location addr to size bytes. Returns the memory address of the reallocated memory, which may be different than the address passed in.
Free the memory at address addr
Returns a Digest subclass by name
require 'openssl' OpenSSL::Digest("MD5") # => OpenSSL::Digest::MD5 Digest("Foo") # => NameError: wrong constant name Foo
Returns a Digest subclass by name
require 'openssl' OpenSSL::Digest("MD5") # => OpenSSL::Digest::MD5 Digest("Foo") # => NameError: wrong constant name Foo
See any remaining errors held in queue.
Any errors you see here are probably due to a bug in Ruby’s OpenSSL implementation.
Return true if the named file exists.
file_name can be an IO object.
“file exists” means that stat() or fstat() system call is successful.
Returns true if the named file is readable by the effective user and group id of this process. See eaccess(3).
Note that some OS-level security features may cause this to return true even though the file is not readable by the effective user/group.
Returns true if the named file has the sticky bit set.
file_name can be an IO object.
Initiates garbage collection, even if manually disabled.
The full_mark keyword argument determines whether or not to perform a major garbage collection cycle. When set to true, a major garbage collection cycle is run, meaning all objects are marked. When set to false, a minor garbage collection cycle is run, meaning only young objects are marked.
The immediate_mark keyword argument determines whether or not to perform incremental marking. When set to true, marking is completed during the call to this method. When set to false, marking is performed in steps that are interleaved with future Ruby code execution, so marking might not be completed during this method call. Note that if full_mark is false, then marking will always be immediate, regardless of the value of immediate_mark.
The immediate_sweep keyword argument determines whether or not to defer sweeping (using lazy sweep). When set to false, sweeping is performed in steps that are interleaved with future Ruby code execution, so sweeping might not be completed during this method call. When set to true, sweeping is completed during the call to this method.
Note: These keyword arguments are implementation and version-dependent. They are not guaranteed to be future-compatible and may be ignored if the underlying implementation does not support them.
Returns a Hash containing information about the GC.
The contents of the hash are implementation-specific and may change in the future without notice.
The hash includes internal statistics about GC such as:
The total number of garbage collections run since application start (count includes both minor and major garbage collections)
The total time spent in garbage collections (in milliseconds)
The total number of :heap_eden_pages + :heap_tomb_pages
The number of pages that can fit into the buffer that holds references to all pages
The total number of pages the application could allocate without additional GC
The total number of slots in all :heap_allocated_pages
The total number of slots which contain live objects
The total number of slots which do not contain live objects
The total number of slots with pending finalizers to be run
The total number of objects marked in the last GC
The total number of pages which contain at least one live slot
The total number of pages which do not contain any live slots
The cumulative number of pages allocated since application start
The cumulative number of pages freed since application start
The cumulative number of objects allocated since application start
The cumulative number of objects freed since application start
Amount of memory allocated on the heap for objects. Decreased by any GC
When :malloc_increase_bytes crosses this limit, GC is triggered
The total number of minor garbage collections run since process start
The total number of major garbage collections run since process start
The total number of compactions run since process start
The total number of times the read barrier was triggered during compaction
The total number of objects compaction has moved
The total number of objects without write barriers
When :remembered_wb_unprotected_objects crosses this limit, major GC is triggered
Number of live, old objects which have survived at least 3 garbage collections
When :old_objects crosses this limit, major GC is triggered
Amount of memory allocated on the heap for objects. Decreased by major GC
When :oldmalloc_increase_bytes crosses this limit, major GC is triggered
If the optional argument, hash, is given, it is overwritten and returned. This is intended to avoid the probe effect.
This method is only expected to work on CRuby.
Returns the time used to execute the given block as a Benchmark::Tms object. Takes label option.
require 'benchmark' n = 1000000 time = Benchmark.measure do n.times { a = "1" } end puts time
Generates:
0.220000 0.000000 0.220000 ( 0.227313)
Returns the elapsed real time used to execute the given block. The unit of time is seconds.
Benchmark.realtime { "a" * 1_000_000_000 } #=> 0.5098029999935534
Returns the time used to execute the given block as a Benchmark::Tms object. Takes label option.
require 'benchmark' n = 1000000 time = Benchmark.measure do n.times { a = "1" } end puts time
Generates:
0.220000 0.000000 0.220000 ( 0.227313)
Returns the elapsed real time used to execute the given block. The unit of time is seconds.
Benchmark.realtime { "a" * 1_000_000_000 } #=> 0.5098029999935534
Top level install helper method. Allows you to install gems interactively:
% irb >> Gem.install "minitest" Fetching: minitest-5.14.0.gem (100%) => [#<Gem::Specification:0x1013b4528 @name="minitest", ...>]
Get the default RubyGems API host. This is normally https://rubygems.org.
Set the default RubyGems API host.
Set array of platforms this RubyGems supports (primarily for testing).
Array of platforms this RubyGems supports.
The directory prefix this RubyGems was installed at. If your prefix is in a standard location (ie, rubygems is installed where you’d expect it to be), then prefix returns nil.