Array of platforms this RubyGems supports.
Computes the tangent of x
(expressed in radians).
Domain: (-INFINITY, INFINITY)
Codomain: (-INFINITY, INFINITY)
Math.tan(0) #=> 0.0
Computes the hyperbolic tangent of x
(expressed in radians).
Domain: (-INFINITY, INFINITY)
Codomain: (-1, 1)
Math.tanh(0) #=> 0.0
Waits for all children, returning an array of pid/status pairs (where status is a Process::Status
object).
fork { sleep 0.2; exit 2 } #=> 27432 fork { sleep 0.1; exit 1 } #=> 27433 fork { exit 0 } #=> 27434 p Process.waitall
produces:
[[30982, #<Process::Status: pid 30982 exit 0>], [30979, #<Process::Status: pid 30979 exit 1>], [30976, #<Process::Status: pid 30976 exit 2>]]
Some operating systems retain the status of terminated child processes until the parent collects that status (normally using some variant of wait()
). If the parent never collects this status, the child stays around as a zombie process. Process::detach
prevents this by setting up a separate Ruby thread whose sole job is to reap the status of the process pid when it terminates. Use detach
only when you do not intend to explicitly wait for the child to terminate.
The waiting thread returns the exit status of the detached process when it terminates, so you can use Thread#join
to know the result. If specified pid is not a valid child process ID, the thread returns nil
immediately.
The waiting thread has pid
method which returns the pid.
In this first example, we don’t reap the first child process, so it appears as a zombie in the process status display.
p1 = fork { sleep 0.1 } p2 = fork { sleep 0.2 } Process.waitpid(p2) sleep 2 system("ps -ho pid,state -p #{p1}")
produces:
27389 Z
In the next example, Process::detach
is used to reap the child automatically.
p1 = fork { sleep 0.1 } p2 = fork { sleep 0.2 } Process.detach(p1) Process.waitpid(p2) sleep 2 system("ps -ho pid,state -p #{p1}")
(produces no output)
Detach the process from controlling terminal and run in the background as system daemon. Unless the argument nochdir is true (i.e. non false), it changes the current working directory to the root (“/”). Unless the argument noclose is true, daemon() will redirect standard input, standard output and standard error to /dev/null. Return zero on success, or raise one of Errno::*.
Add the –update-sources option
Raises a MissingAttributeError
, NotAvailableValueError
, MissingTagError
or NotExpectedTagError
if the element is not properly formatted.
Returns a Hash
containing the following keys:
Number of started SSL/TLS handshakes in server mode
Number of established SSL/TLS sessions in server mode
Number of start renegotiations in server mode
Number of sessions that were removed due to cache overflow
Number of successfully reused connections
Number of sessions proposed by clients that were not found in the cache
Number of sessions in the internal session cache
Number of sessions retrieved from the external cache in server mode
Number of started SSL/TLS handshakes in client mode
Number of established SSL/TLS sessions in client mode
Number of start renegotiations in client mode
Number of sessions proposed by clients that were found in the cache but had expired due to timeouts
Takes the first digit of the reply code to determine the status type