Adds a pre-uninstall hook that will be passed an Gem::Uninstaller instance and the spec that will be uninstalled when Gem::Uninstaller#uninstall is called
The path to standard location of the user’s configuration directory.
Adds DidYouMean functionality to an error using a given spell checker
Returns whether or not the constant const is defined. You may optionally pass the type of const as [const, type], such as:
have_const(%w[PTHREAD_MUTEX_INITIALIZER pthread_mutex_t], "pthread.h")
You may also pass additional headers to check against in addition to the common header files, and additional flags to opt which are then passed along to the compiler.
If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with HAVE_CONST_.
For example, if have_const('foo') returned true, then the HAVE_CONST_FOO preprocessor macro would be passed to the compiler.
Tests for the presence of a --with-config or --without-config option. Returns true if the with option is given, false if the without option is given, and the default value otherwise.
This can be useful for adding custom definitions, such as debug information.
Example:
if with_config("debug") $defs.push("-DOSSL_DEBUG") unless $defs.include? "-DOSSL_DEBUG" end
Sets a target name that the user can then use to configure various “with” options with on the command line by using that name. For example, if the target is set to “foo”, then the user could use the --with-foo-dir=prefix, --with-foo-include=dir and --with-foo-lib=dir command line options to tell where to search for header/library files.
You may pass along additional parameters to specify default values. If one is given it is taken as default prefix, and if two are given they are taken as “include” and “lib” defaults in that order.
In any case, the return value will be an array of determined “include” and “lib” directories, either of which can be nil if no corresponding command line option is given when no default value is specified.
Note that dir_config only adds to the list of places to search for libraries and include files. It does not link the libraries into your application.
Returns compile/link information about an installed library in a tuple of [cflags, ldflags, libs], by using the command found first in the following commands:
If --with-{pkg}-config={command} is given via command line option: {command} {options}
{pkg}-config {options}
pkg-config {options} {pkg}
Where options is the option name without dashes, for instance "cflags" for the --cflags flag.
The values obtained are appended to $INCFLAGS, $CFLAGS, $LDFLAGS and $libs.
If one or more options argument is given, the config command is invoked with the options and a stripped output string is returned without modifying any of the global values mentioned above.
Return the number of observers associated with this object.
Notify observers of a change in state if this object’s changed state is true.
This will invoke the method named in add_observer, passing *arg. The changed state is then set to false.
*arg
Any arguments to pass to the observers.
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.
Sets the minimum and maximum supported protocol versions. See min_version= and max_version=.