Generates a header file consisting of the various macro definitions generated by other methods such as have_func and have_header. These are then wrapped in a custom #ifndef based on the header file name, which defaults to “extconf.h”.
For example:
# extconf.rb require 'mkmf' have_func('realpath') have_header('sys/utime.h') create_header create_makefile('foo')
The above script would generate the following extconf.h file:
#ifndef EXTCONF_H #define EXTCONF_H #define HAVE_REALPATH 1 #define HAVE_SYS_UTIME_H 1 #endif
Given that the create_header method generates a file based on definitions set earlier in your extconf.rb file, you will probably want to make this one of the last methods you call in your script.
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} {option}
{pkg}-config {option}
pkg-config {option} {pkg}
Where {option} is, for instance, --cflags.
The values obtained are appended to +$CFLAGS+, +$LDFLAGS+ and +$libs+.
If an option argument is given, the config command is invoked with the option and a stripped output string is returned without modifying any of the global values mentioned above.
Leaves exclusive section.
Returns true if this monitor is locked by any thread
Returns true if this monitor is locked by current thread.
Creates a new MonitorMixin::ConditionVariable associated with the receiver.
Open3.pipeline_start starts a list of commands as a pipeline. No pipes are created for stdin of the first command and stdout of the last command.
Open3.pipeline_start(cmd1, cmd2, ... [, opts]) {|wait_threads|
...
}
wait_threads = Open3.pipeline_start(cmd1, cmd2, ... [, opts])
...
Each cmd is a string or an array. If it is an array, the elements are passed to Process.spawn.
cmd: commandline command line string which is passed to a shell [env, commandline, opts] command line string which is passed to a shell [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell) [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell) Note that env and opts are optional, as for Process.spawn.
Example:
# Run xeyes in 10 seconds. Open3.pipeline_start("xeyes") {|ts| sleep 10 t = ts[0] Process.kill("TERM", t.pid) p t.value #=> #<Process::Status: pid 911 SIGTERM (signal 15)> } # Convert pdf to ps and send it to a printer. # Collect error message of pdftops and lpr. pdf_file = "paper.pdf" printer = "printer-name" err_r, err_w = IO.pipe Open3.pipeline_start(["pdftops", pdf_file, "-"], ["lpr", "-P#{printer}"], :err=>err_w) {|ts| err_w.close p err_r.read # error messages of pdftops and lpr. }
Open3.pipeline_start starts a list of commands as a pipeline. No pipes are created for stdin of the first command and stdout of the last command.
Open3.pipeline_start(cmd1, cmd2, ... [, opts]) {|wait_threads|
...
}
wait_threads = Open3.pipeline_start(cmd1, cmd2, ... [, opts])
...
Each cmd is a string or an array. If it is an array, the elements are passed to Process.spawn.
cmd: commandline command line string which is passed to a shell [env, commandline, opts] command line string which is passed to a shell [env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell) [env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell) Note that env and opts are optional, as for Process.spawn.
Example:
# Run xeyes in 10 seconds. Open3.pipeline_start("xeyes") {|ts| sleep 10 t = ts[0] Process.kill("TERM", t.pid) p t.value #=> #<Process::Status: pid 911 SIGTERM (signal 15)> } # Convert pdf to ps and send it to a printer. # Collect error message of pdftops and lpr. pdf_file = "paper.pdf" printer = "printer-name" err_r, err_w = IO.pipe Open3.pipeline_start(["pdftops", pdf_file, "-"], ["lpr", "-P#{printer}"], :err=>err_w) {|ts| err_w.close p err_r.read # error messages of pdftops and lpr. }
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
CLOCK_MONOTONIC
SUSv3 to 4, Linux 2.5.63, FreeBSD 3.0, NetBSD 2.0, OpenBSD 3.4, macOS 10.12
CLOCK_PROCESS_CPUTIME_ID
SUSv3 to 4, Linux 2.5.63, 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
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.
This integer returns the current initial length of the buffer.
This sets the initial length of the buffer to length, if length > 0, otherwise its value isn’t changed.