Results for: "OptionParser"

Returns whether exactly one element meets a given criterion.

With no argument and no block, returns whether exactly one element is truthy:

(1..1).one?           # => true
[1, nil, false].one?  # => true
(1..4).one?           # => false
{foo: 0}.one?         # => true
{foo: 0, bar: 1}.one? # => false
[].one?               # => false

With argument pattern and no block, returns whether for exactly one element element, pattern === element:

[nil, false, 0].one?(Integer)        # => true
[nil, false, 0].one?(Numeric)        # => true
[nil, false, 0].one?(Float)          # => false
%w[bar baz bat bam].one?(/m/)        # => true
%w[bar baz bat bam].one?(/foo/)      # => false
%w[bar baz bat bam].one?('ba')       # => false
{foo: 0, bar: 1, baz: 2}.one?(Array) # => false
{foo: 0}.one?(Array)                 # => true
[].one?(Integer)                     # => false

With a block given, returns whether the block returns a truthy value for exactly one element:

(1..4).one? {|element| element < 2 }                     # => true
(1..4).one? {|element| element < 1 }                     # => false
{foo: 0, bar: 1, baz: 2}.one? {|key, value| value < 1 }  # => true
{foo: 0, bar: 1, baz: 2}.one? {|key, value| value < 2 } # => false

Related: none?, all?, any?.

Returns whether no element meets a given criterion.

With no argument and no block, returns whether no element is truthy:

(1..4).none?           # => false
[nil, false].none?     # => true
{foo: 0}.none?         # => false
{foo: 0, bar: 1}.none? # => false
[].none?               # => true

With argument pattern and no block, returns whether for no element element, pattern === element:

[nil, false, 1.1].none?(Integer)      # => true
%w[bar baz bat bam].none?(/m/)        # => false
%w[bar baz bat bam].none?(/foo/)      # => true
%w[bar baz bat bam].none?('ba')       # => true
{foo: 0, bar: 1, baz: 2}.none?(Hash)  # => true
{foo: 0}.none?(Array)                 # => false
[].none?(Integer)                     # => true

With a block given, returns whether the block returns a truthy value for no element:

(1..4).none? {|element| element < 1 }                     # => true
(1..4).none? {|element| element < 2 }                     # => false
{foo: 0, bar: 1, baz: 2}.none? {|key, value| value < 0 }  # => true
{foo: 0, bar: 1, baz: 2}.none? {|key, value| value < 1 } # => false

Related: one?, all?, any?.

Returns whether for any element object == element:

(1..4).include?(2)                       # => true
(1..4).include?(5)                       # => false
(1..4).include?('2')                     # => false
%w[a b c d].include?('b')                # => true
%w[a b c d].include?('2')                # => false
{foo: 0, bar: 1, baz: 2}.include?(:foo)  # => true
{foo: 0, bar: 1, baz: 2}.include?('foo') # => false
{foo: 0, bar: 1, baz: 2}.include?(0)     # => false

For positive integer n, returns an array containing all but the first n elements:

r = (1..4)
r.drop(3)  # => [4]
r.drop(2)  # => [3, 4]
r.drop(1)  # => [2, 3, 4]
r.drop(0)  # => [1, 2, 3, 4]
r.drop(50) # => []

h = {foo: 0, bar: 1, baz: 2, bat: 3}
h.drop(2) # => [[:baz, 2], [:bat, 3]]

Returns an array of all non-nil elements:

a = [nil, 0, nil, 'a', false, nil, false, nil, 'a', nil, 0, nil]
a.compact # => [0, "a", false, false, "a", 0]

Writes warning message msg to $stderr. This method is called by Ruby for all emitted warnings. A category may be included with the warning.

See the documentation of the Warning module for how to customize this.

Determines the equality of two numbers by comparing to zero, or using the epsilon value

Set up the coverage measurement.

Note that this method does not start the measurement itself. Use Coverage.resume to start the measurement.

You may want to use Coverage.start to setup and then start the measurement.

Enables the coverage measurement. See the documentation of Coverage class in detail. This is equivalent to Coverage.setup and Coverage.resume.

Resets the process of reading the /etc/passwd file, so that the next call to ::getpwent will return the first entry again.

Provides a convenient Ruby iterator which executes a block for each entry in the /etc/passwd file.

The code block is passed an Passwd struct.

See ::getpwent above for details.

Example:

require 'etc'

Etc.passwd {|u|
  puts u.name + " = " + u.gecos
}

Resets the process of reading the /etc/group file, so that the next call to ::getgrent will return the first entry again.

Returns system configuration directory.

This is typically "/etc", but is modified by the prefix used when Ruby was compiled. For example, if Ruby is built and installed in /usr/local, returns "/usr/local/etc" on other platforms than Windows.

On Windows, this always returns the directory provided by the system.

Returns system configuration variable using sysconf().

name should be a constant under Etc which begins with SC_.

The return value is an integer or nil. nil means indefinite limit. (sysconf() returns -1 but errno is not set.)

Etc.sysconf(Etc::SC_ARG_MAX) #=> 2097152
Etc.sysconf(Etc::SC_LOGIN_NAME_MAX) #=> 256

Returns system configuration variable using confstr().

name should be a constant under Etc which begins with CS_.

The return value is a string or nil. nil means no configuration-defined value. (confstr() returns 0 but errno is not set.)

Etc.confstr(Etc::CS_PATH) #=> "/bin:/usr/bin"

# GNU/Linux
Etc.confstr(Etc::CS_GNU_LIBC_VERSION) #=> "glibc 2.18"
Etc.confstr(Etc::CS_GNU_LIBPTHREAD_VERSION) #=> "NPTL 2.18"

Creates a new handler that opens library, and returns an instance of Fiddle::Handle.

If nil is given for the library, Fiddle::Handle::DEFAULT is used, which is the equivalent to RTLD_DEFAULT. See man 3 dlopen for more.

lib = Fiddle.dlopen(nil)

The default is dependent on OS, and provide a handle for all libraries already loaded. For example, in most cases you can use this to access libc functions, or ruby functions like rb_str_new.

See Fiddle::Handle.new for more.

Creates a new handler that opens library, and returns an instance of Fiddle::Handle.

If nil is given for the library, Fiddle::Handle::DEFAULT is used, which is the equivalent to RTLD_DEFAULT. See man 3 dlopen for more.

lib = Fiddle.dlopen(nil)

The default is dependent on OS, and provide a handle for all libraries already loaded. For example, in most cases you can use this to access libc functions, or ruby functions like rb_str_new.

See Fiddle::Handle.new for more.

Returns a String containing the generated JSON data.

See also JSON.fast_generate, JSON.pretty_generate.

Argument obj is the Ruby object to be converted to JSON.

Argument opts, if given, contains a Hash of options for the generation. See Generating Options.

When obj is an Array, returns a String containing a JSON array:

obj = ["foo", 1.0, true, false, nil]
json = JSON.generate(obj)
json # => '["foo",1.0,true,false,null]'

When obj is a Hash, returns a String containing a JSON object:

obj = {foo: 0, bar: 's', baz: :bat}
json = JSON.generate(obj)
json # => '{"foo":0,"bar":"s","baz":"bat"}'

For examples of generating from other Ruby objects, see Generating JSON from Other Objects.

Raises an exception if any formatting option is not a String.

Raises an exception if obj contains circular references:

a = []; b = []; a.push(b); b.push(a)
# Raises JSON::NestingError (nesting of 100 is too deep):
JSON.generate(a)

Encodes string using String.encode.

Convert str to to_enc. to_enc and from_enc are given as constants of Kconv or Encoding objects.

Convert str to to_enc. to_enc and from_enc are given as constants of Kconv or Encoding objects.

Returns whether input encoding is EUC-JP or not.

Note don’t expect this return value is MatchData.

Returns whether input encoding is EUC-JP or not.

Note don’t expect this return value is MatchData.

Open the syslog facility. Raises a runtime exception if it is already open.

Can be called with or without a code block. If called with a block, the Syslog object created is passed to the block.

If the syslog is already open, raises a RuntimeError.

ident is a String which identifies the calling program.

options is the logical OR of any of the following:

LOG_CONS

If there is an error while sending to the system logger, write directly to the console instead.

LOG_NDELAY

Open the connection now, rather than waiting for the first message to be written.

LOG_NOWAIT

Don’t wait for any child processes created while logging messages. (Has no effect on Linux.)

LOG_ODELAY

Opposite of LOG_NDELAY; wait until a message is sent before opening the connection. (This is the default.)

LOG_PERROR

Print the message to stderr as well as sending it to syslog. (Not in POSIX.1-2001.)

LOG_PID

Include the current process ID with each message.

facility describes the type of program opening the syslog, and is the logical OR of any of the following which are defined for the host OS:

LOG_AUTH

Security or authorization. Deprecated, use LOG_AUTHPRIV instead.

LOG_AUTHPRIV

Security or authorization messages which should be kept private.

LOG_CONSOLE

System console message.

LOG_CRON

System task scheduler (cron or at).

LOG_DAEMON

A system daemon which has no facility value of its own.

LOG_FTP

An FTP server.

LOG_KERN

A kernel message (not sendable by user processes, so not of much use to Ruby, but listed here for completeness).

LOG_LPR

Line printer subsystem.

LOG_MAIL

Mail delivery or transport subsystem.

LOG_NEWS

Usenet news system.

LOG_NTP

Network Time Protocol server.

LOG_SECURITY

General security message.

LOG_SYSLOG

Messages generated internally by syslog.

LOG_USER

Generic user-level message.

LOG_UUCP

UUCP subsystem.

LOG_LOCAL0 to LOG_LOCAL7

Locally-defined facilities.

Example:

Syslog.open("webrick", Syslog::LOG_PID,
            Syslog::LOG_DAEMON | Syslog::LOG_LOCAL3)