Allows the opening of various resources including URIs.
If the first argument responds to the ‘open’ method, ‘open’ is called on it with the rest of the arguments.
If the first argument is a string that begins with <code>(protocol)://<code>, it is parsed by URI.parse
. If the parsed object responds to the ‘open’ method, ‘open’ is called on it with the rest of the arguments.
Otherwise, Kernel#open
is called.
OpenURI::OpenRead#open
provides URI::HTTP#open
, URI::HTTPS#open
and URI::FTP#open
, Kernel#open
.
We can accept URIs and strings that begin with http://, https:// and ftp://. In these cases, the opened file object is extended by OpenURI::Meta
.
Open stdin, stdout, and stderr streams and start external executable. In addition, a thread to wait for the started process is created. The thread has a pid method and a thread variable :pid which is the pid of the started process.
Block form:
Open3.popen3([env,] cmd... [, opts]) {|stdin, stdout, stderr, wait_thr| pid = wait_thr.pid # pid of the started process. ... exit_status = wait_thr.value # Process::Status object returned. }
Non-block form:
stdin, stdout, stderr, wait_thr = Open3.popen3([env,] cmd... [, opts]) pid = wait_thr[:pid] # pid of the started process ... stdin.close # stdin, stdout and stderr should be closed explicitly in this form. stdout.close stderr.close exit_status = wait_thr.value # Process::Status object returned.
The parameters env, cmd, and opts are passed to Process.spawn
. A commandline string and a list of argument strings can be accepted as follows:
Open3.popen3("echo abc") {|i, o, e, t| ... } Open3.popen3("echo", "abc") {|i, o, e, t| ... } Open3.popen3(["echo", "argv0"], "abc") {|i, o, e, t| ... }
If the last parameter, opts, is a Hash
, it is recognized as an option for Process.spawn
.
Open3.popen3("pwd", :chdir=>"/") {|i,o,e,t| p o.read.chomp #=> "/" }
wait_thr.value waits for the termination of the process. The block form also waits for the process when it returns.
Closing stdin, stdout and stderr does not wait for the process to complete.
You should be careful to avoid deadlocks. Since pipes are fixed length buffers, Open3.popen3
(“prog”) {|i, o, e, t| o.read } deadlocks if the program generates too much output on stderr. You should read stdout and stderr simultaneously (using threads or IO.select
). However, if you don’t need stderr output, you can use Open3.popen2
. If merged stdout and stderr output is not a problem, you can use Open3.popen2e
. If you really need stdout and stderr output as separate strings, you can consider Open3.capture3
.
Open stdin, stdout, and stderr streams and start external executable. In addition, a thread to wait for the started process is created. The thread has a pid method and a thread variable :pid which is the pid of the started process.
Block form:
Open3.popen3([env,] cmd... [, opts]) {|stdin, stdout, stderr, wait_thr| pid = wait_thr.pid # pid of the started process. ... exit_status = wait_thr.value # Process::Status object returned. }
Non-block form:
stdin, stdout, stderr, wait_thr = Open3.popen3([env,] cmd... [, opts]) pid = wait_thr[:pid] # pid of the started process ... stdin.close # stdin, stdout and stderr should be closed explicitly in this form. stdout.close stderr.close exit_status = wait_thr.value # Process::Status object returned.
The parameters env, cmd, and opts are passed to Process.spawn
. A commandline string and a list of argument strings can be accepted as follows:
Open3.popen3("echo abc") {|i, o, e, t| ... } Open3.popen3("echo", "abc") {|i, o, e, t| ... } Open3.popen3(["echo", "argv0"], "abc") {|i, o, e, t| ... }
If the last parameter, opts, is a Hash
, it is recognized as an option for Process.spawn
.
Open3.popen3("pwd", :chdir=>"/") {|i,o,e,t| p o.read.chomp #=> "/" }
wait_thr.value waits for the termination of the process. The block form also waits for the process when it returns.
Closing stdin, stdout and stderr does not wait for the process to complete.
You should be careful to avoid deadlocks. Since pipes are fixed length buffers, Open3.popen3
(“prog”) {|i, o, e, t| o.read } deadlocks if the program generates too much output on stderr. You should read stdout and stderr simultaneously (using threads or IO.select
). However, if you don’t need stderr output, you can use Open3.popen2
. If merged stdout and stderr output is not a problem, you can use Open3.popen2e
. If you really need stdout and stderr output as separate strings, you can consider Open3.capture3
.
Open3.popen2
is similar to Open3.popen3
except that it doesn’t create a pipe for the standard error stream.
Block form:
Open3.popen2([env,] cmd... [, opts]) {|stdin, stdout, wait_thr| pid = wait_thr.pid # pid of the started process. ... exit_status = wait_thr.value # Process::Status object returned. }
Non-block form:
stdin, stdout, wait_thr = Open3.popen2([env,] cmd... [, opts]) ... stdin.close # stdin and stdout should be closed explicitly in this form. stdout.close
See Process.spawn
for the optional hash arguments env and opts.
Example:
Open3.popen2("wc -c") {|i,o,t| i.print "answer to life the universe and everything" i.close p o.gets #=> "42\n" } Open3.popen2("bc -q") {|i,o,t| i.puts "obase=13" i.puts "6 * 9" p o.gets #=> "42\n" } Open3.popen2("dc") {|i,o,t| i.print "42P" i.close p o.read #=> "*" }
Open3.popen2
is similar to Open3.popen3
except that it doesn’t create a pipe for the standard error stream.
Block form:
Open3.popen2([env,] cmd... [, opts]) {|stdin, stdout, wait_thr| pid = wait_thr.pid # pid of the started process. ... exit_status = wait_thr.value # Process::Status object returned. }
Non-block form:
stdin, stdout, wait_thr = Open3.popen2([env,] cmd... [, opts]) ... stdin.close # stdin and stdout should be closed explicitly in this form. stdout.close
See Process.spawn
for the optional hash arguments env and opts.
Example:
Open3.popen2("wc -c") {|i,o,t| i.print "answer to life the universe and everything" i.close p o.gets #=> "42\n" } Open3.popen2("bc -q") {|i,o,t| i.puts "obase=13" i.puts "6 * 9" p o.gets #=> "42\n" } Open3.popen2("dc") {|i,o,t| i.print "42P" i.close p o.read #=> "*" }
Open3.popen2e
is similar to Open3.popen3
except that it merges the standard output stream and the standard error stream.
Block form:
Open3.popen2e([env,] cmd... [, opts]) {|stdin, stdout_and_stderr, wait_thr| pid = wait_thr.pid # pid of the started process. ... exit_status = wait_thr.value # Process::Status object returned. }
Non-block form:
stdin, stdout_and_stderr, wait_thr = Open3.popen2e([env,] cmd... [, opts]) ... stdin.close # stdin and stdout_and_stderr should be closed explicitly in this form. stdout_and_stderr.close
See Process.spawn
for the optional hash arguments env and opts.
Example:
# check gcc warnings source = "foo.c" Open3.popen2e("gcc", "-Wall", source) {|i,oe,t| oe.each {|line| if /warning/ =~ line ... end } }
Open3.popen2e
is similar to Open3.popen3
except that it merges the standard output stream and the standard error stream.
Block form:
Open3.popen2e([env,] cmd... [, opts]) {|stdin, stdout_and_stderr, wait_thr| pid = wait_thr.pid # pid of the started process. ... exit_status = wait_thr.value # Process::Status object returned. }
Non-block form:
stdin, stdout_and_stderr, wait_thr = Open3.popen2e([env,] cmd... [, opts]) ... stdin.close # stdin and stdout_and_stderr should be closed explicitly in this form. stdout_and_stderr.close
See Process.spawn
for the optional hash arguments env and opts.
Example:
# check gcc warnings source = "foo.c" Open3.popen2e("gcc", "-Wall", source) {|i,oe,t| oe.each {|line| if /warning/ =~ line ... end } }
Open3.capture3
captures the standard output and the standard error of a command.
stdout_str, stderr_str, status = Open3.capture3([env,] cmd... [, opts])
The arguments env, cmd and opts are passed to Open3.popen3
except opts[:stdin_data]
and opts[:binmode]
. See Process.spawn
.
If opts[:stdin_data]
is specified, it is sent to the command’s standard input.
If opts[:binmode]
is true, internal pipes are set to binary mode.
Examples:
# dot is a command of graphviz. graph = <<'End' digraph g { a -> b } End drawn_graph, dot_log = Open3.capture3("dot -v", :stdin_data=>graph) o, e, s = Open3.capture3("echo abc; sort >&2", :stdin_data=>"foo\nbar\nbaz\n") p o #=> "abc\n" p e #=> "bar\nbaz\nfoo\n" p s #=> #<Process::Status: pid 32682 exit 0> # generate a thumbnail image using the convert command of ImageMagick. # However, if the image is really stored in a file, # system("convert", "-thumbnail", "80", "png:#{filename}", "png:-") is better # because of reduced memory consumption. # But if the image is stored in a DB or generated by the gnuplot Open3.capture2 example, # Open3.capture3 should be considered. # image = File.read("/usr/share/openclipart/png/animals/mammals/sheep-md-v0.1.png", :binmode=>true) thumbnail, err, s = Open3.capture3("convert -thumbnail 80 png:- png:-", :stdin_data=>image, :binmode=>true) if s.success? STDOUT.binmode; print thumbnail end
Open3.capture3
captures the standard output and the standard error of a command.
stdout_str, stderr_str, status = Open3.capture3([env,] cmd... [, opts])
The arguments env, cmd and opts are passed to Open3.popen3
except opts[:stdin_data]
and opts[:binmode]
. See Process.spawn
.
If opts[:stdin_data]
is specified, it is sent to the command’s standard input.
If opts[:binmode]
is true, internal pipes are set to binary mode.
Examples:
# dot is a command of graphviz. graph = <<'End' digraph g { a -> b } End drawn_graph, dot_log = Open3.capture3("dot -v", :stdin_data=>graph) o, e, s = Open3.capture3("echo abc; sort >&2", :stdin_data=>"foo\nbar\nbaz\n") p o #=> "abc\n" p e #=> "bar\nbaz\nfoo\n" p s #=> #<Process::Status: pid 32682 exit 0> # generate a thumbnail image using the convert command of ImageMagick. # However, if the image is really stored in a file, # system("convert", "-thumbnail", "80", "png:#{filename}", "png:-") is better # because of reduced memory consumption. # But if the image is stored in a DB or generated by the gnuplot Open3.capture2 example, # Open3.capture3 should be considered. # image = File.read("/usr/share/openclipart/png/animals/mammals/sheep-md-v0.1.png", :binmode=>true) thumbnail, err, s = Open3.capture3("convert -thumbnail 80 png:- png:-", :stdin_data=>image, :binmode=>true) if s.success? STDOUT.binmode; print thumbnail end
Open3.capture2
captures the standard output of a command.
stdout_str, status = Open3.capture2([env,] cmd... [, opts])
The arguments env, cmd and opts are passed to Open3.popen3
except opts[:stdin_data]
and opts[:binmode]
. See Process.spawn
.
If opts[:stdin_data]
is specified, it is sent to the command’s standard input.
If opts[:binmode]
is true, internal pipes are set to binary mode.
Example:
# factor is a command for integer factorization. o, s = Open3.capture2("factor", :stdin_data=>"42") p o #=> "42: 2 3 7\n" # generate x**2 graph in png using gnuplot. gnuplot_commands = <<"End" set terminal png plot x**2, "-" with lines 1 14 2 1 3 8 4 5 e End image, s = Open3.capture2("gnuplot", :stdin_data=>gnuplot_commands, :binmode=>true)
Open3.capture2
captures the standard output of a command.
stdout_str, status = Open3.capture2([env,] cmd... [, opts])
The arguments env, cmd and opts are passed to Open3.popen3
except opts[:stdin_data]
and opts[:binmode]
. See Process.spawn
.
If opts[:stdin_data]
is specified, it is sent to the command’s standard input.
If opts[:binmode]
is true, internal pipes are set to binary mode.
Example:
# factor is a command for integer factorization. o, s = Open3.capture2("factor", :stdin_data=>"42") p o #=> "42: 2 3 7\n" # generate x**2 graph in png using gnuplot. gnuplot_commands = <<"End" set terminal png plot x**2, "-" with lines 1 14 2 1 3 8 4 5 e End image, s = Open3.capture2("gnuplot", :stdin_data=>gnuplot_commands, :binmode=>true)
Open3.capture2e
captures the standard output and the standard error of a command.
stdout_and_stderr_str, status = Open3.capture2e([env,] cmd... [, opts])
The arguments env, cmd and opts are passed to Open3.popen3
except opts[:stdin_data]
and opts[:binmode]
. See Process.spawn
.
If opts[:stdin_data]
is specified, it is sent to the command’s standard input.
If opts[:binmode]
is true, internal pipes are set to binary mode.
Example:
# capture make log make_log, s = Open3.capture2e("make")
Open3.capture2e
captures the standard output and the standard error of a command.
stdout_and_stderr_str, status = Open3.capture2e([env,] cmd... [, opts])
The arguments env, cmd and opts are passed to Open3.popen3
except opts[:stdin_data]
and opts[:binmode]
. See Process.spawn
.
If opts[:stdin_data]
is specified, it is sent to the command’s standard input.
If opts[:binmode]
is true, internal pipes are set to binary mode.
Example:
# capture make log make_log, s = Open3.capture2e("make")
Retrieve the PathSupport
object that RubyGems uses to lookup files.
Initialize the filesystem paths to use from env
. env
is a hash-like object (typically ENV
) that is queried for ‘GEM_HOME’, ‘GEM_PATH’, and ‘GEM_SPEC_CACHE’ Keys for the env
hash should be Strings, and values of the hash should be Strings or nil
.
Prints the amount of time the supplied block takes to run using the debug UI output.
Raises a TypeError
to prevent cloning.
Perform an operation in a block, raising an error if it takes longer than sec
seconds to complete.
sec
Number of seconds to wait for the block to terminate. Any number may be used, including Floats to specify fractional seconds. A value of 0 or nil
will execute the block without any timeout.
klass
Exception
Class
to raise if the block fails to terminate in sec
seconds. Omitting will use the default, Timeout::Error
message
Error
message to raise with Exception
Class
. Omitting will use the default, “execution expired”
Returns the result of the block if the block completed before sec
seconds, otherwise throws an exception, based on the value of klass
.
The exception thrown to terminate the given block cannot be rescued inside the block unless klass
is given explicitly. However, the block can use ensure to prevent the handling of the exception. For that reason, this method cannot be relied on to enforce timeouts for untrusted blocks.
Note that this is both a method of module Timeout
, so you can include Timeout
into your classes so they have a timeout
method, as well as a module method, so you can call it directly as Timeout.timeout()
.
Perform an operation in a block, raising an error if it takes longer than sec
seconds to complete.
sec
Number of seconds to wait for the block to terminate. Any number may be used, including Floats to specify fractional seconds. A value of 0 or nil
will execute the block without any timeout.
klass
Exception
Class
to raise if the block fails to terminate in sec
seconds. Omitting will use the default, Timeout::Error
message
Error
message to raise with Exception
Class
. Omitting will use the default, “execution expired”
Returns the result of the block if the block completed before sec
seconds, otherwise throws an exception, based on the value of klass
.
The exception thrown to terminate the given block cannot be rescued inside the block unless klass
is given explicitly. However, the block can use ensure to prevent the handling of the exception. For that reason, this method cannot be relied on to enforce timeouts for untrusted blocks.
Note that this is both a method of module Timeout
, so you can include Timeout
into your classes so they have a timeout
method, as well as a module method, so you can call it directly as Timeout.timeout()
.
Calculates the error function of x
.
Domain: (-INFINITY, INFINITY)
Codomain: (-1, 1)
Math.erf(0) #=> 0.0