Equivalent to Kernel::gets, except readline raises EOFError at end of file.
Returns an array containing the lines returned by calling Kernel.gets(sep) until the end of file.
Suspends the current thread for duration seconds (which may be any number, including a Float with fractional seconds). Returns the actual number of seconds slept (rounded), which may be less than that asked for if another thread calls Thread#run. Called without an argument, sleep() will sleep forever.
Time.new #=> 2008-03-08 19:56:19 +0900 sleep 1.2 #=> 1 Time.new #=> 2008-03-08 19:56:20 +0900 sleep 1.9 #=> 2 Time.new #=> 2008-03-08 19:56:22 +0900
Combines all elements of enum by applying a binary operation, specified by a block or a symbol that names a method or operator.
The inject and reduce methods are aliases. There is no performance benefit to either.
If you specify a block, then for each element in enum the block is passed an accumulator value (memo) and the element. If you specify a symbol instead, then each element in the collection will be passed to the named method of memo. In either case, the result becomes the new value for memo. At the end of the iteration, the final value of memo is the return value for the method.
If you do not explicitly specify an initial value for memo, then the first element of collection is used as the initial value of memo.
# Sum some numbers (5..10).reduce(:+) #=> 45 # Same using a block and inject (5..10).inject { |sum, n| sum + n } #=> 45 # Multiply some numbers (5..10).reduce(1, :*) #=> 151200 # Same using a block (5..10).inject(1) { |product, n| product * n } #=> 151200 # find the longest word longest = %w{ cat sheep bear }.inject do |memo, word| memo.length > word.length ? memo : word end longest #=> "sheep"
Returns the number of online processors.
The result is intended as the number of processes to use all available processors.
This method is implemented using:
sched_getaffinity(): Linux
sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX
Example:
require 'etc' p Etc.nprocessors #=> 4
The result might be smaller number than physical cpus especially when ruby process is bound to specific cpus. This is intended for getting better parallel processing.
Example: (Linux)
linux$ taskset 0x3 ./ruby -retc -e "p Etc.nprocessors" #=> 2
Encodes string using String.encode.
Shows the prompt and reads the inputted line with line editing. The inputted line is added to the history if add_hist is true.
Returns nil when the inputted line is empty and user inputs EOF (Presses ^D on UNIX).
Raises IOError exception if one of below conditions are satisfied.
stdin was closed.
stdout was closed.
This method supports thread. Switches the thread context when waits inputting line.
Supports line edit when inputs line. Provides VI and Emacs editing mode. Default is Emacs editing mode.
NOTE: Terminates ruby interpreter and does not return the terminal status after user pressed ‘^C’ when wait inputting line. Give 3 examples that avoid it.
Catches the Interrupt exception by pressed ^C after returns terminal status:
require "readline"
stty_save = `stty -g`.chomp
begin
while buf = Readline.readline
p buf
end
rescue Interrupt
system("stty", stty_save)
exit
end
end
end
Catches the INT signal by pressed ^C after returns terminal status:
require "readline" stty_save = `stty -g`.chomp trap("INT") { system "stty", stty_save; exit } while buf = Readline.readline p buf end
Ignores pressing ^C:
require "readline" trap("INT", "SIG_IGN") while buf = Readline.readline p buf end
Can make as follows with Readline::HISTORY constant. It does not record to the history if the inputted line is empty or the same it as last one.
require "readline" while buf = Readline.readline("> ", true) # p Readline::HISTORY.to_a Readline::HISTORY.pop if /^\s*$/ =~ buf begin if Readline::HISTORY[Readline::HISTORY.length-2] == buf Readline::HISTORY.pop end rescue IndexError end # p Readline::HISTORY.to_a print "-> ", buf, "\n" end
Returns the facility number used in the last call to open()
Returns self, for backward compatibility.
Returns true if the named file is a symbolic link.
Returns true if the named file has the sticky bit set.
file_name can be an IO object.
Returns true if the named files are identical.
file_1 and file_2 can be an IO object.
open("a", "w") {} p File.identical?("a", "a") #=> true p File.identical?("a", "./a") #=> true File.link("a", "b") p File.identical?("a", "b") #=> true File.symlink("a", "c") p File.identical?("a", "c") #=> true open("d", "w") {} p File.identical?("a", "d") #=> false
URI::split(uri)
Splits the string on following parts and returns array with result:
Scheme
Userinfo
Host
Port
Registry
Path
Opaque
Query
Fragment
require 'uri' URI.split("http://www.ruby-lang.org/") # => ["http", nil, "www.ruby-lang.org", nil, nil, "/", nil, nil, nil]
Open3.pipeline_r starts a list of commands as a pipeline with a pipe which connects to stdout of the last command.
Open3.pipeline_r(cmd1, cmd2, ... [, opts]) {|last_stdout, wait_threads|
...
}
last_stdout, wait_threads = Open3.pipeline_r(cmd1, cmd2, ... [, opts])
...
last_stdout.close
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:
Open3.pipeline_r("zcat /var/log/apache2/access.log.*.gz",
[{"LANG"=>"C"}, "grep", "GET /favicon.ico"],
"logresolve") {|o, ts|
o.each_line {|line|
...
}
}
Open3.pipeline_r("yes", "head -10") {|o, ts|
p o.read #=> "y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n"
p ts[0].value #=> #<Process::Status: pid 24910 SIGPIPE (signal 13)>
p ts[1].value #=> #<Process::Status: pid 24913 exit 0>
}
Open3.pipeline_r starts a list of commands as a pipeline with a pipe which connects to stdout of the last command.
Open3.pipeline_r(cmd1, cmd2, ... [, opts]) {|last_stdout, wait_threads|
...
}
last_stdout, wait_threads = Open3.pipeline_r(cmd1, cmd2, ... [, opts])
...
last_stdout.close
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:
Open3.pipeline_r("zcat /var/log/apache2/access.log.*.gz",
[{"LANG"=>"C"}, "grep", "GET /favicon.ico"],
"logresolve") {|o, ts|
o.each_line {|line|
...
}
}
Open3.pipeline_r("yes", "head -10") {|o, ts|
p o.read #=> "y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n"
p ts[0].value #=> #<Process::Status: pid 24910 SIGPIPE (signal 13)>
p ts[1].value #=> #<Process::Status: pid 24913 exit 0>
}
Open3.pipeline_w starts a list of commands as a pipeline with a pipe which connects to stdin of the first command.
Open3.pipeline_w(cmd1, cmd2, ... [, opts]) {|first_stdin, wait_threads|
...
}
first_stdin, wait_threads = Open3.pipeline_w(cmd1, cmd2, ... [, opts])
...
first_stdin.close
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:
Open3.pipeline_w("bzip2 -c", :out=>"/tmp/hello.bz2") {|i, ts| i.puts "hello" }
Open3.pipeline_w starts a list of commands as a pipeline with a pipe which connects to stdin of the first command.
Open3.pipeline_w(cmd1, cmd2, ... [, opts]) {|first_stdin, wait_threads|
...
}
first_stdin, wait_threads = Open3.pipeline_w(cmd1, cmd2, ... [, opts])
...
first_stdin.close
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:
Open3.pipeline_w("bzip2 -c", :out=>"/tmp/hello.bz2") {|i, ts| i.puts "hello" }
Open3.pipeline starts a list of commands as a pipeline. It waits for the completion of the commands. No pipes are created for stdin of the first command and stdout of the last command.
status_list = Open3.pipeline(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 Process.spawn.
Example:
fname = "/usr/share/man/man1/ruby.1.gz" p Open3.pipeline(["zcat", fname], "nroff -man", "less") #=> [#<Process::Status: pid 11817 exit 0>, # #<Process::Status: pid 11820 exit 0>, # #<Process::Status: pid 11828 exit 0>] fname = "/usr/share/man/man1/ls.1.gz" Open3.pipeline(["zcat", fname], "nroff -man", "colcrt") # convert PDF to PS and send to a printer by lpr pdf_file = "paper.pdf" printer = "printer-name" Open3.pipeline(["pdftops", pdf_file, "-"], ["lpr", "-P#{printer}"]) # count lines Open3.pipeline("sort", "uniq -c", :in=>"names.txt", :out=>"count") # cyclic pipeline r,w = IO.pipe w.print "ibase=14\n10\n" Open3.pipeline("bc", "tee /dev/tty", :in=>r, :out=>w) #=> 14 # 18 # 22 # 30 # 42 # 58 # 78 # 106 # 202