Results for: "Logger"

• Argument csv_string, if given, must be a String object; defaults to a new empty String.

• Arguments options, if given, should be generating options. See Options for Generating.

Creates a new CSV object via CSV.new(csv_string, **options); calls the block with the CSV object, which the block may modify; returns the String generated from the CSV object.

Note that a passed String is modified by this method. Pass csv_string.dup if the String must be preserved.

This method has one additional option: :encoding, which sets the base Encoding for the output if no no str is specified. CSV needs this hint if you plan to output non-ASCII compatible data.

Add lines:

input_string = "foo,0\nbar,1\nbaz,2\n"
output_string = CSV.generate(input_string) do |csv|
  csv << ['bat', 3]
  csv << ['bam', 4]
end
output_string # => "foo,0\nbar,1\nbaz,2\nbat,3\nbam,4\n"
input_string # => "foo,0\nbar,1\nbaz,2\nbat,3\nbam,4\n"
output_string.equal?(input_string) # => true # Same string, modified

Add lines into new string, preserving old string:

input_string = "foo,0\nbar,1\nbaz,2\n"
output_string = CSV.generate(input_string.dup) do |csv|
  csv << ['bat', 3]
  csv << ['bam', 4]
end
output_string # => "foo,0\nbar,1\nbaz,2\nbat,3\nbam,4\n"
input_string # => "foo,0\nbar,1\nbaz,2\n"
output_string.equal?(input_string) # => false # Different strings

Create lines from nothing:

output_string = CSV.generate do |csv|
  csv << ['foo', 0]
  csv << ['bar', 1]
  csv << ['baz', 2]
end
output_string # => "foo,0\nbar,1\nbaz,2\n"

Raises an exception if csv_string is not a String object:

# Raises TypeError (no implicit conversion of Integer into String)
CSV.generate(0)

Returns an Array containing field converters; see Field Converters:

csv = CSV.new('')
csv.converters # => []
csv.convert(:integer)
csv.converters # => [:integer]
csv.convert(proc {|x| x.to_s })
csv.converters

Notes that you need to call +Ractor.make_shareable(CSV::Converters)+ on the main Ractor to use this method.

Converts arg to an Integer. Numeric types are converted directly (with floating point numbers being truncated). base (0, or between 2 and 36) is a base for integer string representation. If arg is a String, when base is omitted or equals zero, radix indicators (0, 0b, and 0x) are honored. In any case, strings should consist only of one or more digits, except for that a sign, one underscore between two digits, and leading/trailing spaces are optional. This behavior is different from that of String#to_i. Non string values will be converted by first trying to_int, then to_i.

Passing nil raises a TypeError, while passing a String that does not conform with numeric representation raises an ArgumentError. This behavior can be altered by passing exception: false, in this case a not convertible value will return nil.

Integer(123.999)    #=> 123
Integer("0x1a")     #=> 26
Integer(Time.new)   #=> 1204973019
Integer("0930", 10) #=> 930
Integer("111", 2)   #=> 7
Integer(" +1_0 ")   #=> 10
Integer(nil)        #=> TypeError: can't convert nil into Integer
Integer("x")        #=> ArgumentError: invalid value for Integer(): "x"

Integer("x", exception: false)        #=> nil

Computes the natural logarithm of decimal to the specified number of digits of precision, numeric.

If decimal is zero or negative, raises Math::DomainError.

If decimal is positive infinity, returns Infinity.

If decimal is NaN, returns NaN.

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)

Log a message with the specified priority. Example:

Syslog.log(Syslog::LOG_CRIT, "Out of disk space")
Syslog.log(Syslog::LOG_CRIT, "User %s logged in", ENV['USER'])

The priority levels, in descending order, are:

LOG_EMERG

System is unusable

LOG_ALERT

Action needs to be taken immediately

LOG_CRIT

A critical condition has occurred

LOG_ERR

An error occurred

LOG_WARNING

Warning of a possible problem

LOG_NOTICE

A normal but significant condition occurred

LOG_INFO

Informational message

LOG_DEBUG

Debugging information

Each priority level also has a shortcut method that logs with it’s named priority. As an example, the two following statements would produce the same result:

Syslog.log(Syslog::LOG_ALERT, "Out of memory")
Syslog.alert("Out of memory")

Returns the logarithm of x. If additional second argument is given, it will be the base of logarithm. Otherwise it is e (for the natural logarithm).

Domain: (0, INFINITY)

Codomain: (-INFINITY, INFINITY)

Math.log(0)          #=> -Infinity
Math.log(1)          #=> 0.0
Math.log(Math::E)    #=> 1.0
Math.log(Math::E**3) #=> 3.0
Math.log(12, 3)      #=> 2.2618595071429146

Returns the base 2 logarithm of x.

Domain: (0, INFINITY)

Codomain: (-INFINITY, INFINITY)

Math.log2(1)      #=> 0.0
Math.log2(2)      #=> 1.0
Math.log2(32768)  #=> 15.0
Math.log2(65536)  #=> 16.0

Returns the base 10 logarithm of x.

Domain: (0, INFINITY)

Codomain: (-INFINITY, INFINITY)

Math.log10(1)       #=> 0.0
Math.log10(10)      #=> 1.0
Math.log10(10**100) #=> 100.0

creates a TCP/IP server on port and calls the block for each connection accepted. The block is called with a socket and a client_address as an Addrinfo object.

If host is specified, it is used with port to determine the server addresses.

The socket is not closed when the block returns. So application should close it explicitly.

This method calls the block sequentially. It means that the next connection is not accepted until the block returns. So concurrent mechanism, thread for example, should be used to service multiple clients at a time.

Note that Addrinfo.getaddrinfo is used to determine the server socket addresses. When Addrinfo.getaddrinfo returns two or more addresses, IPv4 and IPv6 address for example, all of them are used. Socket.tcp_server_loop succeeds if one socket can be used at least.

# Sequential echo server.
# It services only one client at a time.
Socket.tcp_server_loop(16807) {|sock, client_addrinfo|
  begin
    IO.copy_stream(sock, sock)
  ensure
    sock.close
  end
}

# Threaded echo server
# It services multiple clients at a time.
# Note that it may accept connections too much.
Socket.tcp_server_loop(16807) {|sock, client_addrinfo|
  Thread.new {
    begin
      IO.copy_stream(sock, sock)
    ensure
      sock.close
    end
  }
}

creates a UDP/IP server on port and calls the block for each message arrived. The block is called with the message and its source information.

This method allocates sockets internally using port. If host is specified, it is used conjunction with port to determine the server addresses.

The msg is a string.

The msg_src is a Socket::UDPSource object. It is used for reply.

# UDP/IP echo server.
Socket.udp_server_loop(9261) {|msg, msg_src|
  msg_src.reply msg
}

creates a UNIX socket server on path. It calls the block for each socket accepted.

If host is specified, it is used with port to determine the server ports.

The socket is not closed when the block returns. So application should close it.

This method deletes the socket file pointed by path at first if the file is a socket file and it is owned by the user of the application. This is safe only if the directory of path is not changed by a malicious user. So don’t use /tmp/malicious-users-directory/socket. Note that /tmp/socket and /tmp/your-private-directory/socket is safe assuming that /tmp has sticky bit.

# Sequential echo server.
# It services only one client at a time.
Socket.unix_server_loop("/tmp/sock") {|sock, client_addrinfo|
  begin
    IO.copy_stream(sock, sock)
  ensure
    sock.close
  end
}

Generates new parameters for the algorithm. algo_name is a String that represents the algorithm. The optional argument options is a Hash that specifies the options specific to the algorithm. The order of the options can be important.

A block can be passed optionally. The meaning of the arguments passed to the block varies depending on the implementation of the algorithm. The block may be called once or multiple times, or may not even be called.

For the supported options, see the documentation for the ‘openssl genpkey’ utility command.

Example

pkey = OpenSSL::PKey.generate_parameters("DSA", "dsa_paramgen_bits" => 2048)
p pkey.p.num_bits #=> 2048

Run UDP/IP server loop on the given sockets.

The return value of Socket.udp_server_sockets is appropriate for the argument.

It calls the block for each message received.