return true if the current ractor is main ractor
Returns an array of all existing Thread objects that belong to this group.
ThreadGroup::Default.list #=> [#<Thread:0x401bdf4c run>]
Basically the same as ::new. However, if class Thread is subclassed, then calling start in that subclass will not invoke the subclass’s initialize method.
Returns the main thread.
Stops execution of the current thread, putting it into a “sleep” state, and schedules execution of another thread.
a = Thread.new { print "a"; Thread.stop; print "c" } sleep 0.1 while a.status!='sleep' print "b" a.run a.join #=> "abc"
Returns an array of Thread objects for all threads that are either runnable or stopped.
Thread.new { sleep(200) } Thread.new { 1000000.times {|i| i*i } } Thread.new { Thread.stop } Thread.list.each {|t| p t}
This will produce:
#<Thread:0x401b3e84 sleep> #<Thread:0x401b3f38 run> #<Thread:0x401b3fb0 sleep> #<Thread:0x401bdf4c run>
The calling thread will suspend execution and run this thr.
Does not return until thr exits or until the given limit seconds have passed.
If the time limit expires, nil will be returned, otherwise thr is returned.
Any threads not joined will be killed when the main program exits.
If thr had previously raised an exception and the ::abort_on_exception or $DEBUG flags are not set, (so the exception has not yet been processed), it will be processed at this time.
a = Thread.new { print "a"; sleep(10); print "b"; print "c" } x = Thread.new { print "x"; Thread.pass; print "y"; print "z" } x.join # Let thread x finish, thread a will be killed on exit. #=> "axyz"
The following example illustrates the limit parameter.
y = Thread.new { 4.times { sleep 0.1; puts 'tick... ' }} puts "Waiting" until y.join(0.15)
This will produce:
tick... Waiting tick... Waiting tick... tick...
Terminates thr and schedules another thread to be run, returning the terminated Thread. If this is the main thread, or the last thread, exits the process.
Returns the status of thr.
"sleep"Returned if this thread is sleeping or waiting on I/O
"run"When this thread is executing
"aborting"If this thread is aborting
falseWhen this thread is terminated normally
nilIf terminated with an exception.
a = Thread.new { raise("die now") } b = Thread.new { Thread.stop } c = Thread.new { Thread.exit } d = Thread.new { sleep } d.kill #=> #<Thread:0x401b3678 aborting> a.status #=> nil b.status #=> "sleep" c.status #=> false d.status #=> "aborting" Thread.current.status #=> "run"
Returns true if thr is dead or sleeping.
a = Thread.new { Thread.stop } b = Thread.current a.stop? #=> true b.stop? #=> false
Returns the current backtrace of the target thread.
Dump the name, id, and status of thr to a string.
Returns a string containing a human-readable TracePoint status.
Returns internal information of TracePoint.
The contents of the returned value are implementation-specific and may change in the future.
This method is only for debugging TracePoint itself.
A convenience method for TracePoint.new that activates the trace automatically.
trace = TracePoint.trace(:call) { |tp| [tp.lineno, tp.event] } #=> #<TracePoint:enabled> trace.enabled? #=> true
Returns the line number of the event.
Performs a test on one or both of the filesystem entities at the given paths path0 and path1:
Each path path0 or path1 points to a file, directory, device, pipe, etc.
Character char selects a specific test.
The tests:
Each of these tests operates only on the entity at path0, and returns true or false; for a non-existent entity, returns false (does not raise exception):
| Character | Test |
|---|---|
'b' |
Whether the entity is a block device. |
'c' |
Whether the entity is a character device. |
'd' |
Whether the entity is a directory. |
'e' |
Whether the entity is an existing entity. |
'f' |
Whether the entity is an existing regular file. |
'g' |
Whether the entity's setgid bit is set. |
'G' |
Whether the entity's group ownership is equal to the caller's. |
'k' |
Whether the entity's sticky bit is set. |
'l' |
Whether the entity is a symbolic link. |
'o' |
Whether the entity is owned by the caller's effective uid. |
'O' |
Like 'o', but uses the real uid (not the effective uid). |
'p' |
Whether the entity is a FIFO device (named pipe). |
'r' |
Whether the entity is readable by the caller's effective uid/gid. |
'R' |
Like 'r', but uses the real uid/gid (not the effective uid/gid). |
'S' |
Whether the entity is a socket. |
'u' |
Whether the entity's setuid bit is set. |
'w' |
Whether the entity is writable by the caller's effective uid/gid. |
'W' |
Like 'w', but uses the real uid/gid (not the effective uid/gid). |
'x' |
Whether the entity is executable by the caller's effective uid/gid. |
'X' |
Like 'x', but uses the real uid/gid (not the effective uid/git). |
'z' |
Whether the entity exists and is of length zero. |
This test operates only on the entity at path0, and returns an integer size or nil:
| Character | Test |
|---|---|
's' |
Returns positive integer size if the entity exists and has non-zero length, nil otherwise. |
Each of these tests operates only on the entity at path0, and returns a Time object; raises an exception if the entity does not exist:
| Character | Test |
|---|---|
'A' |
Last access time for the entity. |
'C' |
Last change time for the entity. |
'M' |
Last modification time for the entity. |
Each of these tests operates on the modification time (mtime) of each of the entities at path0 and path1, and returns a true or false; returns false if either entity does not exist:
| Character | Test |
|---|---|
'<' |
Whether the 'mtime` at `path0` is less than that at `path1`. |
'=' |
Whether the 'mtime` at `path0` is equal to that at `path1`. |
'>' |
Whether the 'mtime` at `path0` is greater than that at `path1`. |
This test operates on the content of each of the entities at path0 and path1, and returns a true or false; returns false if either entity does not exist:
| Character | Test |
|---|---|
'-' |
Whether the entities exist and are identical. |
Equivalent to method Kernel#gets, except that it raises an exception if called at end-of-stream:
$ cat t.txt | ruby -e "p readlines; readline" ["First line\n", "Second line\n", "\n", "Fourth line\n", "Fifth line\n"] in `readline': end of file reached (EOFError)
Optional keyword argument chomp specifies whether line separators are to be omitted.
Returns an array containing the lines returned by calling Kernel#gets until the end-of-stream is reached; (see Line IO).
With only string argument sep given, returns the remaining lines as determined by line separator sep, or nil if none; see Line Separator:
# Default separator. $ cat t.txt | ruby -e "p readlines" ["First line\n", "Second line\n", "\n", "Fourth line\n", "Fifth line\n"] # Specified separator. $ cat t.txt | ruby -e "p readlines 'li'" ["First li", "ne\nSecond li", "ne\n\nFourth li", "ne\nFifth li", "ne\n"] # Get-all separator. $ cat t.txt | ruby -e "p readlines nil" ["First line\nSecond line\n\nFourth line\nFifth line\n"] # Get-paragraph separator. $ cat t.txt | ruby -e "p readlines ''" ["First line\nSecond line\n\n", "Fourth line\nFifth line\n"]
With only integer argument limit given, limits the number of bytes in the line; see Line Limit:
$cat t.txt | ruby -e "p readlines 10" ["First line", "\n", "Second lin", "e\n", "\n", "Fourth lin", "e\n", "Fifth line", "\n"] $cat t.txt | ruby -e "p readlines 11" ["First line\n", "Second line", "\n", "\n", "Fourth line", "\n", "Fifth line\n"] $cat t.txt | ruby -e "p readlines 12" ["First line\n", "Second line\n", "\n", "Fourth line\n", "Fifth line\n"]
With arguments sep and limit given, combines the two behaviors (see Line Separator and Line Limit).
Optional keyword argument chomp specifies whether line separators are to be omitted:
$ cat t.txt | ruby -e "p readlines(chomp: true)" ["First line", "Second line", "", "Fourth line", "Fifth line"]
Optional keyword arguments enc_opts specify encoding options; see Encoding options.
Returns an integer converted from object.
Tries to convert object to an integer using to_int first and to_i second; see below for exceptions.
With a non-zero base, object must be a string or convertible to a string.
With an integer argument object given, returns object:
Integer(1) # => 1 Integer(-1) # => -1
With a floating-point argument object given, returns object truncated to an integer:
Integer(1.9) # => 1 # Rounds toward zero. Integer(-1.9) # => -1 # Rounds toward zero.
With a string argument object and zero base given, returns object converted to an integer in base 10:
Integer('100') # => 100 Integer('-100') # => -100
With base zero, string object may contain leading characters to specify the actual base (radix indicator):
Integer('0100') # => 64 # Leading '0' specifies base 8. Integer('0b100') # => 4 # Leading '0b' specifies base 2. Integer('0x100') # => 256 # Leading '0x' specifies base 16.
With a positive base (in range 2..36) given, returns object converted to an integer in the given base:
Integer('100', 2) # => 4 Integer('100', 8) # => 64 Integer('-100', 16) # => -256
With a negative base (in range -36..-2) given, returns object converted to the radix indicator if it exists or base:
Integer('0x100', -2) # => 256 Integer('100', -2) # => 4 Integer('0b100', -8) # => 4 Integer('100', -8) # => 64 Integer('0o100', -10) # => 64 Integer('100', -10) # => 100
base -1 is equivalent to the -10 case.
When converting strings, surrounding whitespace and embedded underscores are allowed and ignored:
Integer(' 100 ') # => 100 Integer('-1_0_0', 16) # => -256
Examples with object of various other classes:
Integer(Rational(9, 10)) # => 0 # Rounds toward zero. Integer(Complex(2, 0)) # => 2 # Imaginary part must be zero. Integer(Time.now) # => 1650974042
With the optional keyword argument exception given as true (the default):
Raises TypeError if object does not respond to to_int or to_i.
Raises TypeError if object is nil.
Raises ArgumentError if object is an invalid string.
With exception given as false, an exception of any kind is suppressed and nil is returned.
Returns a URI object derived from the given uri, which may be a URI string or an existing URI object:
# Returns a new URI. uri = URI('http://github.com/ruby/ruby') # => #<URI::HTTP http://github.com/ruby/ruby> # Returns the given URI. URI(uri) # => #<URI::HTTP http://github.com/ruby/ruby>
Returns a URI object derived from the given uri, which may be a URI string or an existing URI object:
# Returns a new URI. uri = URI('http://github.com/ruby/ruby') # => #<URI::HTTP http://github.com/ruby/ruby> # Returns the given URI. URI(uri) # => #<URI::HTTP http://github.com/ruby/ruby>
Creates a new child process by doing one of the following in that process:
Passing string command_line to the shell.
Invoking the executable at exe_path.
This method has potential security vulnerabilities if called with untrusted input; see Command Injection.
Returns:
true if the command exits with status zero.
false if the exit status is a non-zero integer.
nil if the command could not execute.
Raises an exception (instead of returning false or nil) if keyword argument exception is set to true.
Assigns the command’s error status to $?.
The new process is created using the system system call; it may inherit some of its environment from the calling program (possibly including open file descriptors).
Argument env, if given, is a hash that affects ENV for the new process; see Execution Environment.
Argument options is a hash of options for the new process; see Execution Options.
The first required argument is one of the following:
command_line if it is a string, and if it begins with a shell reserved word or special built-in, or if it contains one or more meta characters.
exe_path otherwise.
Argument command_line
String argument command_line is a command line to be passed to a shell; it must begin with a shell reserved word, begin with a special built-in, or contain meta characters:
system('if true; then echo "Foo"; fi') # => true # Shell reserved word. system('exit') # => true # Built-in. system('date > /tmp/date.tmp') # => true # Contains meta character. system('date > /nop/date.tmp') # => false system('date > /nop/date.tmp', exception: true) # Raises RuntimeError.
Assigns the command’s error status to $?:
system('exit') # => true # Built-in. $? # => #<Process::Status: pid 640610 exit 0> system('date > /nop/date.tmp') # => false $? # => #<Process::Status: pid 640742 exit 2>
The command line may also contain arguments and options for the command:
system('echo "Foo"') # => true
Output:
Foo
See Execution Shell for details about the shell.
Raises an exception if the new process could not execute.
Argument exe_path
Argument exe_path is one of the following:
The string path to an executable to be called.
A 2-element array containing the path to an executable and the string to be used as the name of the executing process.
Example:
system('/usr/bin/date') # => true # Path to date on Unix-style system. system('foo') # => nil # Command failed.
Output:
Mon Aug 28 11:43:10 AM CDT 2023
Assigns the command’s error status to $?:
system('/usr/bin/date') # => true $? # => #<Process::Status: pid 645605 exit 0> system('foo') # => nil $? # => #<Process::Status: pid 645608 exit 127>
Ruby invokes the executable directly. This form does not use the shell; see Arguments args for caveats.
system('doesnt_exist') # => nil
If one or more args is given, each is an argument or option to be passed to the executable:
system('echo', 'C*') # => true system('echo', 'hello', 'world') # => true
Output:
C* hello world
Raises an exception if the new process could not execute.
Specifies the handling of signals. The first parameter is a signal name (a string such as “SIGALRM”, “SIGUSR1”, and so on) or a signal number. The characters “SIG” may be omitted from the signal name. The command or block specifies code to be run when the signal is raised. If the command is the string “IGNORE” or “SIG_IGN”, the signal will be ignored. If the command is “DEFAULT” or “SIG_DFL”, the Ruby’s default handler will be invoked. If the command is “EXIT”, the script will be terminated by the signal. If the command is “SYSTEM_DEFAULT”, the operating system’s default handler will be invoked. Otherwise, the given command or block will be run. The special signal name “EXIT” or signal number zero will be invoked just prior to program termination. trap returns the previous handler for the given signal.
Signal.trap(0, proc { puts "Terminating: #{$$}" }) Signal.trap("CLD") { puts "Child died" } fork && Process.wait
produces:
Terminating: 27461 Child died Terminating: 27460
Returns the first element for which the block returns a truthy value.
With a block given, calls the block with successive elements of the collection; returns the first element for which the block returns a truthy value:
(0..9).find {|element| element > 2} # => 3
If no such element is found, calls if_none_proc and returns its return value.
(0..9).find(proc {false}) {|element| element > 12} # => false {foo: 0, bar: 1, baz: 2}.find {|key, value| key.start_with?('b') } # => [:bar, 1] {foo: 0, bar: 1, baz: 2}.find(proc {[]}) {|key, value| key.start_with?('c') } # => []
With no block given, returns an Enumerator.