Returns the status of the last executed child process in the current thread.
Process.wait Process.spawn("ruby", "-e", "exit 13") Process.last_status #=> #<Process::Status: pid 4825 exit 13>
If no child process has ever been executed in the current thread, this returns nil.
Process.last_status #=> nil
Returns a time returned by POSIX clock_gettime() function.
p Process.clock_gettime(Process::CLOCK_MONOTONIC) #=> 896053.968060096
clock_id specifies a kind of clock. It is specified as a constant which begins with Process::CLOCK_ such as Process::CLOCK_REALTIME and Process::CLOCK_MONOTONIC.
The supported constants depends on OS and version. Ruby provides following types of clock_id if available.
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
CLOCK_MONOTONIC
SUSv3 to 4, Linux 2.5.63, FreeBSD 3.0, NetBSD 2.0, OpenBSD 3.4, macOS 10.12, Windows-2000
CLOCK_PROCESS_CPUTIME_ID
SUSv3 to 4, Linux 2.5.63, FreeBSD 9.3, OpenBSD 5.4, macOS 10.12
CLOCK_THREAD_CPUTIME_ID
SUSv3 to 4, Linux 2.5.63, FreeBSD 7.1, OpenBSD 5.4, macOS 10.12
CLOCK_VIRTUAL
FreeBSD 3.0, OpenBSD 2.1
CLOCK_PROF
FreeBSD 3.0, OpenBSD 2.1
CLOCK_REALTIME_FAST
FreeBSD 8.1
CLOCK_REALTIME_PRECISE
FreeBSD 8.1
CLOCK_REALTIME_COARSE
Linux 2.6.32
CLOCK_REALTIME_ALARM
Linux 3.0
CLOCK_MONOTONIC_FAST
FreeBSD 8.1
CLOCK_MONOTONIC_PRECISE
FreeBSD 8.1
CLOCK_MONOTONIC_COARSE
Linux 2.6.32
CLOCK_MONOTONIC_RAW
Linux 2.6.28, macOS 10.12
CLOCK_MONOTONIC_RAW_APPROX
macOS 10.12
CLOCK_BOOTTIME
Linux 2.6.39
CLOCK_BOOTTIME_ALARM
Linux 3.0
CLOCK_UPTIME
FreeBSD 7.0, OpenBSD 5.5
CLOCK_UPTIME_FAST
FreeBSD 8.1
CLOCK_UPTIME_RAW
macOS 10.12
CLOCK_UPTIME_RAW_APPROX
macOS 10.12
CLOCK_UPTIME_PRECISE
FreeBSD 8.1
CLOCK_SECOND
FreeBSD 8.1
CLOCK_TAI
Linux 3.10
Note that SUS stands for Single Unix Specification. SUS contains POSIX and clock_gettime is defined in the POSIX part. SUS defines CLOCK_REALTIME mandatory but CLOCK_MONOTONIC, CLOCK_PROCESS_CPUTIME_ID and CLOCK_THREAD_CPUTIME_ID are optional.
Also, several symbols are accepted as clock_id. There are emulations for clock_gettime().
For example, Process::CLOCK_REALTIME is defined as :GETTIMEOFDAY_BASED_CLOCK_REALTIME when clock_gettime() is not available.
Emulations for CLOCK_REALTIME:
Use gettimeofday() defined by SUS. (SUSv4 obsoleted it, though.) The resolution is 1 microsecond.
Use time() defined by ISO C. The resolution is 1 second.
Emulations for CLOCK_MONOTONIC:
Use mach_absolute_time(), available on Darwin. The resolution is CPU dependent.
Use the result value of times() defined by POSIX. POSIX defines it as “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_gettime(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:
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.
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.
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 is 1000000. Non-Unix systems may define it a different value, though. If CLOCKS_PER_SEC is 1000000 as SUS, the resolution is 1 microsecond. If CLOCKS_PER_SEC is 1000000 and clock_t is 32 bits integer type, it cannot represent over 72 minutes.
If the given clock_id is not supported, Errno::EINVAL is raised.
unit specifies a type of the return value.
number of seconds as a float (default)
number of milliseconds as a float
number of microseconds as a float
number of seconds as an integer
number of milliseconds as an integer
number of microseconds as an integer
number of nanoseconds as an integer
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 :nanoseconds as the unit.
The origin (zero) of the returned value varies. 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). But some systems count leap seconds and others doesn’t. So the result can be interpreted differently across systems. Time.now is recommended over CLOCK_REALTIME.
@return [String] An error message that includes requirement trees,
which is much more detailed & customizable than the default message
@param [Hash] opts the options to create a message with. @option opts [String] :solver_name The user-facing name of the solver @option opts [String] :possibility_type The generic name of a possibility @option opts [Proc] :reduce_trees A proc that reduced the list of requirement trees @option opts [Proc] :printable_requirement A proc that pretty-prints requirements @option opts [Proc] :additional_message_for_conflict A proc that appends additional
messages for each conflict
@option opts [Proc] :version_for_spec A proc that returns the version number for a
possibility
Determines whether the given ‘requirement` is satisfied by the given `spec`, in the context of the current `activated` dependency graph.
@param [Object] requirement @param [DependencyGraph] activated the current dependency graph in the
resolution process.
@param [Object] spec @return [Boolean] whether ‘requirement` is satisfied by `spec` in the
context of the current `activated` dependency graph.
Parses the current JSON text source and returns the complete data structure as a result.
Creates a new DH instance from scratch by generating random parameters and a key pair.
See also OpenSSL::PKey.generate_parameters and OpenSSL::PKey.generate_key.
size
The desired key size in bits.
generator
The generator.
Indicates whether this DH instance has a private key associated with it or not. The private key may be retrieved with DH#priv_key.
Creates a new DSA instance by generating a private/public key pair from scratch.
See also OpenSSL::PKey.generate_parameters and OpenSSL::PKey.generate_key.
size
The desired key size in bits.
Indicates whether this DSA instance has a private key associated with it or not. The private key may be retrieved with DSA#private_key.
Creates a new EC instance with a new random private and public key.
Returns whether this EC instance has a private key. The private key (BN) can be retrieved with EC#private_key.
Generates an RSA keypair.
See also OpenSSL::PKey.generate_key.
size
The desired key size in bits.
exponent
An odd Integer, normally 3, 17, or 65537.
Does this keypair contain a private key?
A description of the current connection state. This is for diagnostic purposes only.
Sets the time used in the verification. If not set, the current time is used.
See also the man page X509_VERIFY_PARAM_set_time(3).
Creates an OpenSSL::OCSP::Response from status and basic_response.
Returns the status of the response.