Reads and returns the next 1-character string from the stream; raises EOFError
if already at end-of-stream. See Character IO.
f = File.open('t.txt') f.readchar # => "F" f.close f = File.open('t.rus') f.readchar.ord # => 1090 f.close
With a block given, passes each element of self
to the block:
a = [] (1..4).each {|element| a.push(element) } # => 1..4 a # => [1, 2, 3, 4]
Raises an exception unless self.first.respond_to?(:succ)
.
With no block given, returns an enumerator.
With no block given, returns the MatchData
object that describes the match, if any, or nil
if none; the search begins at the given character offset
in string
:
/abra/.match('abracadabra') # => #<MatchData "abra"> /abra/.match('abracadabra', 4) # => #<MatchData "abra"> /abra/.match('abracadabra', 8) # => nil /abra/.match('abracadabra', 800) # => nil string = "\u{5d0 5d1 5e8 5d0}cadabra" /abra/.match(string, 7) #=> #<MatchData "abra"> /abra/.match(string, 8) #=> nil /abra/.match(string.b, 8) #=> #<MatchData "abra">
With a block given, calls the block if and only if a match is found; returns the block’s value:
/abra/.match('abracadabra') {|matchdata| p matchdata } # => #<MatchData "abra"> /abra/.match('abracadabra', 4) {|matchdata| p matchdata } # => #<MatchData "abra"> /abra/.match('abracadabra', 8) {|matchdata| p matchdata } # => nil /abra/.match('abracadabra', 8) {|marchdata| fail 'Cannot happen' } # => nil
Output (from the first two blocks above):
#<MatchData "abra"> #<MatchData "abra"> /(.)(.)(.)/.match("abc")[2] # => "b" /(.)(.)/.match("abc", 1)[2] # => "c"
Returns true
or false
to indicate whether the regexp is matched or not without updating $~ and other related variables. If the second parameter is present, it specifies the position in the string to begin the search.
/R.../.match?("Ruby") # => true /R.../.match?("Ruby", 1) # => false /P.../.match?("Ruby") # => false $& # => nil
Calls the given block once for each element in the set, passing the element as parameter. Returns an enumerator if no block is given.
Calls the given block with the value of each member; returns self
:
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.each {|value| p value }
Output:
"Joe Smith" "123 Maple, Anytown NC" 12345
Returns an Enumerator
if no block is given.
Related: each_pair
.
Equivalent to self.to_s.match
, including possible updates to global variables; see String#match
.
Equivalent to sym.to_s.match?
; see String#match
.
Returns the children of the directory (files and subdirectories, not recursive) as an array of Pathname
objects.
By default, the returned pathnames will have enough information to access the files. If you set with_directory
to false
, then the returned pathnames will contain the filename only.
For example:
pn = Pathname("/usr/lib/ruby/1.8") pn.children # -> [ Pathname:/usr/lib/ruby/1.8/English.rb, Pathname:/usr/lib/ruby/1.8/Env.rb, Pathname:/usr/lib/ruby/1.8/abbrev.rb, ... ] pn.children(false) # -> [ Pathname:English.rb, Pathname:Env.rb, Pathname:abbrev.rb, ... ]
Note that the results never contain the entries .
and ..
in the directory because they are not children.
Checks the status of the child process specified by pid
. Returns nil
if the process is still alive.
If the process is not alive, and raise
was true, a PTY::ChildExited
exception will be raised. Otherwise it will return a Process::Status
instance.
pid
The process id of the process to check
raise
If true
and the process identified by pid
is no longer alive a PTY::ChildExited
is raised.
iterates over the list of Addrinfo
objects obtained by Addrinfo.getaddrinfo
.
Addrinfo.foreach(nil, 80) {|x| p x } #=> #<Addrinfo: 127.0.0.1:80 TCP (:80)> # #<Addrinfo: 127.0.0.1:80 UDP (:80)> # #<Addrinfo: [::1]:80 TCP (:80)> # #<Addrinfo: [::1]:80 UDP (:80)>
Calls the block with each remaining line read from the stream; does nothing if already at end-of-file; returns self
. See Line IO.
Returns the character position of the scan pointer. In the ‘reset’ position, this value is zero. In the ‘terminated’ position (i.e. the string is exhausted), this value is the size of the string.
In short, it’s a 0-based index into the string.
s = StringScanner.new("abc\u00e4def\u00f6ghi") s.charpos # -> 0 s.scan_until(/\u00e4/) # -> "abc\u00E4" s.pos # -> 5 s.charpos # -> 4
Tests whether the given pattern
is matched from the current scan pointer. Returns the length of the match, or nil
. The scan pointer is not advanced.
s = StringScanner.new('test string') p s.match?(/\w+/) # -> 4 p s.match?(/\w+/) # -> 4 p s.match?("test") # -> 4 p s.match?(/\s+/) # -> nil
This returns the value that scan
would return, without advancing the scan pointer. The match register is affected, though.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.check /Fri/ # -> "Fri" s.pos # -> 0 s.matched # -> "Fri" s.check /12/ # -> nil s.matched # -> nil
Mnemonic: it “checks” to see whether a scan
will return a value.
Scans one character and returns it. This method is multibyte character sensitive.
s = StringScanner.new("ab") s.getch # => "a" s.getch # => "b" s.getch # => nil s = StringScanner.new("\244\242".force_encoding("euc-jp")) s.getch # => "\x{A4A2}" # Japanese hira-kana "A" in EUC-JP s.getch # => nil