Returns a copy of self
with each character specified by string selector
translated to the corresponding character in string replacements
. The correspondence is positional:
Each occurrence of the first character specified by selector
is translated to the first character in replacements
.
Each occurrence of the second character specified by selector
is translated to the second character in replacements
.
And so on.
Example:
'hello'.tr('el', 'ip') #=> "hippo"
If replacements
is shorter than selector
, it is implicitly padded with its own last character:
'hello'.tr('aeiou', '-') # => "h-ll-" 'hello'.tr('aeiou', 'AA-') # => "hAll-"
Arguments selector
and replacements
must be valid character selectors (see Character Selectors), and may use any of its valid forms, including negation, ranges, and escaping:
# Negation. 'hello'.tr('^aeiou', '-') # => "-e--o" # Ranges. 'ibm'.tr('b-z', 'a-z') # => "hal" # Escapes. 'hel^lo'.tr('\^aeiou', '-') # => "h-l-l-" # Escaped leading caret. 'i-b-m'.tr('b\-z', 'a-z') # => "ibabm" # Escaped embedded hyphen. 'foo\\bar'.tr('ab\\', 'XYZ') # => "fooZYXr" # Escaped backslash.
Like String#tr
, but modifies self
in place. Returns self
if any changes were made, nil
otherwise.
Gets all key-value pairs in a specific section from the current configuration.
Given the following configurating file being loaded:
config = OpenSSL::Config.load('foo.cnf') #=> #<OpenSSL::Config sections=["default"]> puts config.to_s #=> [ default ] # foo=bar
You can get a hash of the specific section like so:
config['default'] #=> {"foo"=>"bar"}
Read a registry value named name and return its value data. The class of the value is the same as the read
method returns.
If the value type is REG_EXPAND_SZ, returns value data whose environment variables are replaced. If the value type is neither REG_SZ, REG_MULTI_SZ, REG_DWORD, REG_DWORD_BIG_ENDIAN, nor REG_QWORD, TypeError
is raised.
The meaning of rtype is the same as for the read
method.
Retrieve the session data for key key
.
Retrieve the code units offset from the given byte offset.
Returns a Command instance for command_name
Return the configuration information for key
.
Queries the configuration for the given key.
Return value associated with key
from database.
Returns nil
if there is no such key
.
See fetch
for more information.
Returns the value associated with the given key
if found.
If key
is not found, returns nil
.
Returns the value associated with the given key
if found.
If key
is not found, returns nil
.
Get the value for the parameter with a given key.
If the parameter has multiple values, only the first will be retrieved; use params
to get the array of values.
Returns the string field value for the case-insensitive field key
, or nil
if there is no such key; see Fields:
res = Net::HTTP.get_response(hostname, '/todos/1') res['Connection'] # => "keep-alive" res['Nosuch'] # => nil
Note that some field values may be retrieved via convenience methods; see Getters.
Returns a string containing the IP address representation in canonical form.
Splits str
into an array of tokens in the same way the UNIX Bourne shell does.
See Shellwords.shellsplit
for details.
Escapes str
so that it can be safely used in a Bourne shell command line.
See Shellwords.shellescape
for details.
Extracts data from self
.
If block
is not given, forming objects that become the elements of a new array, and returns that array. Otherwise, yields each object.
See Packed Data.
Like String#unpack
, but unpacks and returns only the first extracted object. See Packed Data.
Returns a new String that is a copy of string
.
With no arguments, returns the empty string with the Encoding
ASCII-8BIT
:
s = String.new s # => "" s.encoding # => #<Encoding:ASCII-8BIT>
With optional argument string
and no keyword arguments, returns a copy of string
with the same encoding:
String.new('foo') # => "foo" String.new('тест') # => "тест" String.new('こんにちは') # => "こんにちは"
(Unlike String.new, a string literal like ''
or a string literal always has script encoding.)
With optional keyword argument encoding
, returns a copy of string
with the specified encoding; the encoding
may be an Encoding
object, an encoding name, or an encoding name alias:
String.new('foo', encoding: Encoding::US_ASCII).encoding # => #<Encoding:US-ASCII> String.new('foo', encoding: 'US-ASCII').encoding # => #<Encoding:US-ASCII> String.new('foo', encoding: 'ASCII').encoding # => #<Encoding:US-ASCII>
The given encoding need not be valid for the string’s content, and that validity is not checked:
s = String.new('こんにちは', encoding: 'ascii') s.valid_encoding? # => false
But the given encoding
itself is checked:
String.new('foo', encoding: 'bar') # Raises ArgumentError.
With optional keyword argument capacity
, returns a copy of string
(or an empty string, if string
is not given); the given capacity
is advisory only, and may or may not set the size of the internal buffer, which may in turn affect performance:
String.new(capacity: 1) String.new('foo', capacity: 4096)
Note that Ruby
strings are null-terminated internally, so the internal buffer size will be one or more bytes larger than the requested capacity depending on the encoding.
The string
, encoding
, and capacity
arguments may all be used together:
String.new('hello', encoding: 'UTF-8', capacity: 25)
Compares self
and other_string
, returning:
-1 if other_string
is larger.
0 if the two are equal.
1 if other_string
is smaller.
nil
if the two are incomparable.
Examples:
'foo' <=> 'foo' # => 0 'foo' <=> 'food' # => -1 'food' <=> 'foo' # => 1 'FOO' <=> 'foo' # => -1 'foo' <=> 'FOO' # => 1 'foo' <=> 1 # => nil