Squeezes str in place, returning either str, or nil
if no changes were made.
Returns a basic n-bit checksum of the characters in str, where n is the optional Integer
parameter, defaulting to 16. The result is simply the sum of the binary value of each byte in str modulo 2**n - 1
. This is not a particularly good checksum.
Element Reference — If passed a single index
, returns a substring of one character at that index. If passed a start
index and a length
, returns a substring containing length
characters starting at the start
index. If passed a range
, its beginning and end are interpreted as offsets delimiting the substring to be returned.
In these three cases, if an index is negative, it is counted from the end of the string. For the start
and range
cases the starting index is just before a character and an index matching the string’s size. Additionally, an empty string is returned when the starting index for a character range is at the end of the string.
Returns nil
if the initial index falls outside the string or the length is negative.
If a Regexp
is supplied, the matching portion of the string is returned. If a capture
follows the regular expression, which may be a capture group index or name, follows the regular expression that component of the MatchData
is returned instead.
If a match_str
is given, that string is returned if it occurs in the string.
Returns nil
if the regular expression does not match or the match string cannot be found.
a = "hello there" a[1] #=> "e" a[2, 3] #=> "llo" a[2..3] #=> "ll" a[-3, 2] #=> "er" a[7..-2] #=> "her" a[-4..-2] #=> "her" a[-2..-4] #=> "" a[11, 0] #=> "" a[11] #=> nil a[12, 0] #=> nil a[12..-1] #=> nil a[/[aeiou](.)\1/] #=> "ell" a[/[aeiou](.)\1/, 0] #=> "ell" a[/[aeiou](.)\1/, 1] #=> "l" a[/[aeiou](.)\1/, 2] #=> nil a[/(?<vowel>[aeiou])(?<non_vowel>[^aeiou])/, "non_vowel"] #=> "l" a[/(?<vowel>[aeiou])(?<non_vowel>[^aeiou])/, "vowel"] #=> "e" a["lo"] #=> "lo" a["bye"] #=> nil
Deletes the specified portion from str, and returns the portion deleted.
string = "this is a string" string.slice!(2) #=> "i" string.slice!(3..6) #=> " is " string.slice!(/s.*t/) #=> "sa st" string.slice!("r") #=> "r" string #=> "thing"
Searches sep or pattern (regexp) in the string and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".partition("l") #=> ["he", "l", "lo"] "hello".partition("x") #=> ["hello", "", ""] "hello".partition(/.l/) #=> ["h", "el", "lo"]
Searches sep or pattern (regexp) in the string from the end of the string, and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".rpartition("l") #=> ["hel", "l", "o"] "hello".rpartition("x") #=> ["", "", "hello"] "hello".rpartition(/.l/) #=> ["he", "ll", "o"]
Returns a copied string whose encoding is ASCII-8BIT.
The first form returns a copy of str
transcoded to encoding encoding
. The second form returns a copy of str
transcoded from src_encoding to dst_encoding. The last form returns a copy of str
transcoded to Encoding.default_internal
.
By default, the first and second form raise Encoding::UndefinedConversionError
for characters that are undefined in the destination encoding, and Encoding::InvalidByteSequenceError
for invalid byte sequences in the source encoding. The last form by default does not raise exceptions but uses replacement strings.
The options
Hash
gives details for conversion and can have the following keys:
If the value is :replace
, encode
replaces invalid byte sequences in str
with the replacement character. The default is to raise the Encoding::InvalidByteSequenceError
exception
If the value is :replace
, encode
replaces characters which are undefined in the destination encoding with the replacement character. The default is to raise the Encoding::UndefinedConversionError
.
Sets the replacement string to the given value. The default replacement string is “uFFFD” for Unicode encoding forms, and “?” otherwise.
Sets the replacement string by the given object for undefined character. The object should be a Hash
, a Proc
, a Method
, or an object which has [] method. Its key is an undefined character encoded in the source encoding of current transcoder. Its value can be any encoding until it can be converted into the destination encoding of the transcoder.
The value must be :text
or :attr
. If the value is :text
encode
replaces undefined characters with their (upper-case hexadecimal) numeric character references. ‘&’, ‘<’, and ‘>’ are converted to “&”, “<”, and “>”, respectively. If the value is :attr
, encode
also quotes the replacement result (using ‘“’), and replaces ‘”’ with “"”.
Replaces LF (“n”) with CR (“r”) if value is true.
Replaces LF (“n”) with CRLF (“rn”) if value is true.
Replaces CRLF (“rn”) and CR (“r”) with LF (“n”) if value is true.
The first form transcodes the contents of str from str.encoding to encoding
. The second form transcodes the contents of str from src_encoding to dst_encoding. The options Hash
gives details for conversion. See String#encode
for details. Returns the string even if no changes were made.
Changes the encoding to encoding
and returns self.
Returns true for a string which is encoded correctly.
"\xc2\xa1".force_encoding("UTF-8").valid_encoding? #=> true "\xc2".force_encoding("UTF-8").valid_encoding? #=> false "\x80".force_encoding("UTF-8").valid_encoding? #=> false
Processes a copy of str as described under String#tr
, then removes duplicate characters in regions that were affected by the translation.
"hello".tr_s('l', 'r') #=> "hero" "hello".tr_s('el', '*') #=> "h*o" "hello".tr_s('el', 'hx') #=> "hhxo"
Get the address as an Integer
for the function named name
. The function is searched via dlsym on RTLD_NEXT.
See man(3) dlsym() for more info.
Get the address as an Integer
for the function named name
.
Fetch struct member name
Get the underlying pointer for ruby object val
and return it as a Fiddle::Pointer
object.
Returns integer stored at index.
If start and length are given, a string containing the bytes from start of length will be returned.
Get 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"}
Retrieves a weakly referenced object with the given key
Retrieve the session data for key key
.