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. }
The iterator version of the tsort
method. obj.tsort_each
is similar to obj.tsort.each
, but modification of obj during the iteration may lead to unexpected results.
tsort_each
returns nil
. If there is a cycle, TSort::Cyclic
is raised.
class G include TSort def initialize(g) @g = g end def tsort_each_child(n, &b) @g[n].each(&b) end def tsort_each_node(&b) @g.each_key(&b) end end graph = G.new({1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}) graph.tsort_each {|n| p n } #=> 4 # 2 # 3 # 1
The iterator version of the TSort.tsort
method.
The graph is represented by each_node and each_child. each_node should have call
method which yields for each node in the graph. each_child should have call
method which takes a node argument and yields for each child node.
g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]} each_node = lambda {|&b| g.each_key(&b) } each_child = lambda {|n, &b| g[n].each(&b) } TSort.tsort_each(each_node, each_child) {|n| p n } #=> 4 # 2 # 3 # 1
Returns the time resolution returned by POSIX clock_getres
() function.
clock_id
specifies a kind of clock. See the document of Process.clock_gettime
for details.
clock_id
can be a symbol as Process.clock_gettime
. However the result may not be accurate. For example, +Process.clock_getres(:GETTIMEOFDAY_BASED_CLOCK_REALTIME)+ returns 1.0e-06 which means 1 microsecond, but actual resolution can be more coarse.
If the given clock_id
is not supported, Errno::EINVAL is raised.
unit
specifies a type of the return value. Process.clock_getres
accepts unit
as Process.clock_gettime
. The default value, :float_second
, is also same as Process.clock_gettime
.
Process.clock_getres
also accepts :hertz
as unit
. :hertz
means a the reciprocal of :float_second
.
:hertz
can be used to obtain the exact value of the clock ticks per second for times() function and CLOCKS_PER_SEC for clock() function.
+Process.clock_getres(:TIMES_BASED_CLOCK_PROCESS_CPUTIME_ID, :hertz)+ returns the clock ticks per second.
+Process.clock_getres(:CLOCK_BASED_CLOCK_PROCESS_CPUTIME_ID, :hertz)+ returns CLOCKS_PER_SEC.
p Process.clock_getres(Process::CLOCK_MONOTONIC) #=> 1.0e-09
Returns the octet string representation of the elliptic curve point.
conversion_form specifies how the point is converted. Possible values are:
:compressed
:uncompressed
:hybrid