Value from exception raised on the :raise event
Returns an array of the names of global variables. This includes special regexp global variables such as $~ and $+, but does not include the numbered regexp global variables ($1, $2, etc.).
global_variables.grep /std/ #=> [:$stdin, :$stdout, :$stderr]
Returns the names of the current local variables.
fred = 1 for i in 1..10 # ... end local_variables #=> [:fred, :i]
Returns the last Error of the current executing Thread or nil if none
Sets the last Error of the current executing Thread to error
Arguments obj and opts here are the same as arguments obj and opts in JSON.generate.
By default, generates JSON data without checking for circular references in obj (option max_nesting set to false, disabled).
Raises an exception if obj contains circular references:
a = []; b = []; a.push(b); b.push(a) # Raises SystemStackError (stack level too deep): JSON.fast_generate(a)
Arguments obj and opts here are the same as arguments obj and opts in JSON.generate.
Default options are:
{
indent: ' ', # Two spaces
space: ' ', # One space
array_nl: "\n", # Newline
object_nl: "\n" # Newline
}
Example:
obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}} json = JSON.pretty_generate(obj) puts json
Output:
{
"foo": [
"bar",
"baz"
],
"bat": {
"bam": 0,
"bad": 1
}
}
Returns garbage collector generation for the given object.
class B include ObjectSpace def foo trace_object_allocations do obj = Object.new p "Generation is #{allocation_generation(obj)}" end end end B.new.foo #=> "Generation is 3"
See ::trace_object_allocations for more information and examples.
Constant time memory comparison. Inputs are hashed using SHA-256 to mask the length of the secret. Returns true if the strings are identical, false otherwise.
Parse a file at filename. Returns the Psych::Nodes::Document.
Raises a Psych::SyntaxError when a YAML syntax error is detected.
Parse a YAML string in yaml. Returns the Psych::Nodes::Stream. This method can handle multiple YAML documents contained in yaml. filename is used in the exception message if a Psych::SyntaxError is raised.
If a block is given, a Psych::Nodes::Document node will be yielded to the block as it’s being parsed.
Raises a Psych::SyntaxError when a YAML syntax error is detected.
Example:
Psych.parse_stream("---\n - a\n - b") # => #<Psych::Nodes::Stream:0x00> Psych.parse_stream("--- a\n--- b") do |node| node # => #<Psych::Nodes::Document:0x00> end begin Psych.parse_stream("--- `", filename: "file.txt") rescue Psych::SyntaxError => ex ex.file # => 'file.txt' ex.message # => "(file.txt): found character that cannot start any token" end
Raises a TypeError when NilClass is passed.
See Psych::Nodes for more information about YAML AST.
Start a dRuby server locally.
The new dRuby server will become the primary server, even if another server is currently the primary server.
uri is the URI for the server to bind to. If nil, the server will bind to random port on the default local host name and use the default dRuby protocol.
front is the server’s front object. This may be nil.
config is the configuration for the new server. This may be nil.
See DRbServer::new.
Start a dRuby server locally.
The new dRuby server will become the primary server, even if another server is currently the primary server.
uri is the URI for the server to bind to. If nil, the server will bind to random port on the default local host name and use the default dRuby protocol.
front is the server’s front object. This may be nil.
config is the configuration for the new server. This may be nil.
See DRbServer::new.
Get the ‘current’ server.
In the context of execution taking place within the main thread of a dRuby server (typically, as a result of a remote call on the server or one of its objects), the current server is that server. Otherwise, the current server is the primary server.
If the above rule fails to find a server, a DRbServerNotFound error is raised.
Get the ‘current’ server.
In the context of execution taking place within the main thread of a dRuby server (typically, as a result of a remote call on the server or one of its objects), the current server is that server. Otherwise, the current server is the primary server.
If the above rule fails to find a server, a DRbServerNotFound error is raised.
Returns true if the contents of a file a and a file b are identical.
FileUtils.compare_file('somefile', 'somefile') #=> true FileUtils.compare_file('/dev/null', '/dev/urandom') #=> false
Returns true if the contents of a file a and a file b are identical.
FileUtils.compare_file('somefile', 'somefile') #=> true FileUtils.compare_file('/dev/null', '/dev/urandom') #=> false
Returns true if the contents of a stream a and b are identical.
Returns true if the contents of a stream a and b are identical.
Returns whether or not the variable var can be found in the common header files, or within any headers that you provide. If found, a macro is passed as a preprocessor constant to the compiler using the variable name, in uppercase, prepended with HAVE_.
To check variables in an additional library, you need to check that library first using have_library().
For example, if have_var('foo') returned true, then the HAVE_FOO preprocessor macro would be passed to the compiler.
Returns whether or not the given framework can be found on your system. If found, a macro is passed as a preprocessor constant to the compiler using the framework name, in uppercase, prepended with HAVE_FRAMEWORK_.
For example, if have_framework('Ruby') returned true, then the HAVE_FRAMEWORK_RUBY preprocessor macro would be passed to the compiler.
If fw is a pair of the framework name and its header file name that header file is checked, instead of the normally used header file which is named same as the framework.
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. }