Generates new parameters for the algorithm. algo_name is a String that represents the algorithm. The optional argument options is a Hash that specifies the options specific to the algorithm. The order of the options can be important.
A block can be passed optionally. The meaning of the arguments passed to the block varies depending on the implementation of the algorithm. The block may be called once or multiple times, or may not even be called.
For the supported options, see the documentation for the ‘openssl genpkey’ utility command.
pkey = OpenSSL::PKey.generate_parameters("DSA", "dsa_paramgen_bits" => 2048) p pkey.p.num_bits #=> 2048
Run UDP/IP server loop on the given sockets.
The return value of Socket.udp_server_sockets is appropriate for the argument.
It calls the block for each message received.
Returns true if the set is a proper superset of the given set.
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.
Arguments obj and opts here are the same as arguments obj and opts in JSON.generate.
By default, generates JSON data without checking for circular references in obj (option max_nesting set to false, disabled).
Raises an exception if obj contains circular references:
a = []; b = []; a.push(b); b.push(a) # Raises SystemStackError (stack level too deep): JSON.fast_generate(a)
Arguments obj and opts here are the same as arguments obj and opts in JSON.generate.
Default options are:
{
indent: ' ', # Two spaces
space: ' ', # One space
array_nl: "\n", # Newline
object_nl: "\n" # Newline
}
Example:
obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}} json = JSON.pretty_generate(obj) puts json
Output:
{
"foo": [
"bar",
"baz"
],
"bat": {
"bam": 0,
"bad": 1
}
}
A Gem::Version for the currently running RubyGems
Logs src
Returns a clock time as determined by POSIX function clock_gettime():
Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID) # => 198.650379677
Argument clock_id should be a symbol or a constant that specifies the clock whose time is to be returned; see below.
Optional argument unit should be a symbol that specifies the unit to be used in the returned clock time; see below.
Argument clock_id
Argument clock_id specifies the clock whose time is to be returned; it may be a constant such as Process::CLOCK_REALTIME, or a symbol shorthand such as :CLOCK_REALTIME.
The supported clocks depend on the underlying operating system; this method supports the following clocks on the indicated platforms (raises Errno::EINVAL if called with an unsupported clock):
:CLOCK_BOOTTIME: Linux 2.6.39.
:CLOCK_BOOTTIME_ALARM: Linux 3.0.
:CLOCK_MONOTONIC: SUSv3 to 4, Linux 2.5.63, FreeBSD 3.0, NetBSD 2.0, OpenBSD 3.4, macOS 10.12, Windows-2000.
:CLOCK_MONOTONIC_COARSE: Linux 2.6.32.
:CLOCK_MONOTONIC_FAST: FreeBSD 8.1.
:CLOCK_MONOTONIC_PRECISE: FreeBSD 8.1.
:CLOCK_MONOTONIC_RAW: Linux 2.6.28, macOS 10.12.
:CLOCK_MONOTONIC_RAW_APPROX: macOS 10.12.
:CLOCK_PROCESS_CPUTIME_ID: SUSv3 to 4, Linux 2.5.63, FreeBSD 9.3, OpenBSD 5.4, macOS 10.12.
:CLOCK_PROF: FreeBSD 3.0, OpenBSD 2.1.
:CLOCK_REALTIME: SUSv2 to 4, Linux 2.5.63, FreeBSD 3.0, NetBSD 2.0, OpenBSD 2.1, macOS 10.12, Windows-8/Server-2012. Time.now is recommended over +:CLOCK_REALTIME:.
:CLOCK_REALTIME_ALARM: Linux 3.0.
:CLOCK_REALTIME_COARSE: Linux 2.6.32.
:CLOCK_REALTIME_FAST: FreeBSD 8.1.
:CLOCK_REALTIME_PRECISE: FreeBSD 8.1.
:CLOCK_SECOND: FreeBSD 8.1.
:CLOCK_TAI: Linux 3.10.
:CLOCK_THREAD_CPUTIME_ID: SUSv3 to 4, Linux 2.5.63, FreeBSD 7.1, OpenBSD 5.4, macOS 10.12.
:CLOCK_UPTIME: FreeBSD 7.0, OpenBSD 5.5.
:CLOCK_UPTIME_FAST: FreeBSD 8.1.
:CLOCK_UPTIME_PRECISE: FreeBSD 8.1.
:CLOCK_UPTIME_RAW: macOS 10.12.
:CLOCK_UPTIME_RAW_APPROX: macOS 10.12.
:CLOCK_VIRTUAL: FreeBSD 3.0, OpenBSD 2.1.
Note that SUS stands for Single Unix Specification. SUS contains POSIX and clock_gettime is defined in the POSIX part. SUS defines :CLOCK_REALTIME as mandatory but :CLOCK_MONOTONIC, :CLOCK_PROCESS_CPUTIME_ID, and :CLOCK_THREAD_CPUTIME_ID are optional.
Certain emulations are used when the given clock_id is not supported directly:
Emulations for :CLOCK_REALTIME:
:GETTIMEOFDAY_BASED_CLOCK_REALTIME: Use gettimeofday() defined by SUS (deprecated in SUSv4). The resolution is 1 microsecond.
:TIME_BASED_CLOCK_REALTIME: Use time() defined by ISO C. The resolution is 1 second.
Emulations for :CLOCK_MONOTONIC:
:MACH_ABSOLUTE_TIME_BASED_CLOCK_MONOTONIC: Use mach_absolute_time(), available on Darwin. The resolution is CPU dependent.
:TIMES_BASED_CLOCK_MONOTONIC: Use the result value of times() defined by POSIX, thus:
Upon successful completion, times() shall return the elapsed real time, in clock ticks, since an arbitrary point in the past (for example, system start-up time).
For example, GNU/Linux returns a value based on jiffies and it is monotonic. However, 4.4BSD uses gettimeofday() and it is not monotonic. (FreeBSD uses :CLOCK_MONOTONIC instead, though.)
The resolution is the clock tick. “getconf CLK_TCK” command shows the clock ticks per second. (The clock ticks-per-second is defined by HZ macro in older systems.) If it is 100 and clock_t is 32 bits integer type, the resolution is 10 millisecond and cannot represent over 497 days.
Emulations for :CLOCK_PROCESS_CPUTIME_ID:
:GETRUSAGE_BASED_CLOCK_PROCESS_CPUTIME_ID: Use getrusage() defined by SUS. getrusage() is used with RUSAGE_SELF to obtain the time only for the calling process (excluding the time for child processes). The result is addition of user time (ru_utime) and system time (ru_stime). The resolution is 1 microsecond.
:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID: Use times() defined by POSIX. The result is addition of user time (tms_utime) and system time (tms_stime). tms_cutime and tms_cstime are ignored to exclude the time for child processes. The resolution is the clock tick. “getconf CLK_TCK” command shows the clock ticks per second. (The clock ticks per second is defined by HZ macro in older systems.) If it is 100, the resolution is 10 millisecond.
:CLOCK_BASED_CLOCK_PROCESS_CPUTIME_ID: Use clock() defined by ISO C. The resolution is 1/CLOCKS_PER_SEC. CLOCKS_PER_SEC is the C-level macro defined by time.h. SUS defines CLOCKS_PER_SEC as 1000000; other systems may define it differently. If CLOCKS_PER_SEC is 1000000 (as in SUS), the resolution is 1 microsecond. If CLOCKS_PER_SEC is 1000000 and clock_t is a 32-bit integer type, it cannot represent over 72 minutes.
Argument unit
Optional argument unit (default :float_second) specifies the unit for the returned value.
:float_microsecond: Number of microseconds as a float.
:float_millisecond: Number of milliseconds as a float.
:float_second: Number of seconds as a float.
:microsecond: Number of microseconds as an integer.
:millisecond: Number of milliseconds as an integer.
:nanosecond: Number of nanoseconds as an integer.
::second: Number of seconds as an integer.
Examples:
Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :float_microsecond) # => 203605054.825 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :float_millisecond) # => 203643.696848 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :float_second) # => 203.762181929 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :microsecond) # => 204123212 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :millisecond) # => 204298 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :nanosecond) # => 204602286036 Process.clock_gettime(:CLOCK_PROCESS_CPUTIME_ID, :second) # => 204
The underlying function, clock_gettime(), returns a number of nanoseconds. Float object (IEEE 754 double) is not enough to represent the return value for :CLOCK_REALTIME. If the exact nanoseconds value is required, use :nanosecond as the unit.
The origin (time zero) of the returned value is system-dependent, and may be, for example, system start up time, process start up time, the Epoch, etc.
The origin in :CLOCK_REALTIME is defined as the Epoch: 1970-01-01 00:00:00 UTC; some systems count leap seconds and others don’t, so the result may vary across systems.
Returns a clock resolution as determined by POSIX function clock_getres():
Process.clock_getres(:CLOCK_REALTIME) # => 1.0e-09
See Process.clock_gettime for the values of clock_id and unit.
Examples:
Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :float_microsecond) # => 0.001 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :float_millisecond) # => 1.0e-06 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :float_second) # => 1.0e-09 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :microsecond) # => 0 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :millisecond) # => 0 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :nanosecond) # => 1 Process.clock_getres(:CLOCK_PROCESS_CPUTIME_ID, :second) # => 0
In addition to the values for unit supported in Process.clock_gettime, this method supports :hertz, the integer number of clock ticks per second (which is the reciprocal of :float_second):
Process.clock_getres(:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID, :hertz) # => 100.0 Process.clock_getres(:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID, :float_second) # => 0.01
Accuracy: Note that the returned resolution may be inaccurate on some platforms due to underlying bugs. Inaccurate resolutions have been reported for various clocks including :CLOCK_MONOTONIC and :CLOCK_MONOTONIC_RAW on Linux, macOS, BSD or AIX platforms, when using ARM processors, or when using virtualization.
Returns a non-lazy Enumerator converted from the lazy enumerator.
Creates a new Socket::Option object for SOL_SOCKET/SO_LINGER.
onoff should be an integer or a boolean.
secs should be the number of seconds.
p Socket::Option.linger(true, 10) #=> #<Socket::Option: UNSPEC SOCKET LINGER on 10sec>
Returns the linger data in sockopt as a pair of boolean and integer.
sockopt = Socket::Option.linger(true, 10) p sockopt.linger => [true, 10]
Merges the requirements of other into this dependency
Destructive form of merge.
require 'uri' uri = URI.parse("http://my.example.com") uri.merge!("/main.rbx?page=1") uri.to_s # => "http://my.example.com/main.rbx?page=1"
Merges two URIs.
require 'uri' uri = URI.parse("http://my.example.com") uri.merge("/main.rbx?page=1") # => "http://my.example.com/main.rbx?page=1"
Suggests gems based on the supplied gem_name. Returns an array of alternative gem names.