Returns an Addrinfo
object for remote address obtained by getpeername.
Note that addrinfo.protocol is filled by 0.
TCPSocket.open("www.ruby-lang.org", 80) {|s| p s.remote_address #=> #<Addrinfo: 221.186.184.68:80 TCP> } TCPServer.open("127.0.0.1", 1728) {|serv| c = TCPSocket.new("127.0.0.1", 1728) s = serv.accept p s.remote_address #=> #<Addrinfo: 127.0.0.1:36504 TCP> }
s.rest_size
is equivalent to s.rest.size
.
Returns a string containing the IP address representation in canonical form.
Creates a single-row matrix where the values of that row are as given in row
.
Matrix.row_vector([4,5,6]) => 4 5 6
Creates a single-column matrix where the values of that column are as given in column
.
Matrix.column_vector([4,5,6]) => 4 5 6
Returns the submatrix obtained by deleting the specified row and column.
Matrix.diagonal(9, 5, -3, 4).first_minor(1, 2) => 9 0 0 0 0 0 0 0 4
Returns an array of the row vectors of the matrix. See Vector
.
Returns an array of the column vectors of the matrix. See Vector
.
Creates an enumerator for each chunked elements. The beginnings of chunks are defined by pattern and the block.
If pattern === elt
returns true
or the block returns true
for the element, the element is beginning of a chunk.
The ===
and block is called from the first element to the last element of enum. The result for the first element is ignored.
The result enumerator yields the chunked elements as an array. So each
method can be called as follows:
enum.slice_before(pattern).each { |ary| ... } enum.slice_before { |elt| bool }.each { |ary| ... }
Other methods of the Enumerator
class and Enumerable
module, such as to_a
, map
, etc., are also usable.
For example, iteration over ChangeLog entries can be implemented as follows:
# iterate over ChangeLog entries. open("ChangeLog") { |f| f.slice_before(/\A\S/).each { |e| pp e } } # same as above. block is used instead of pattern argument. open("ChangeLog") { |f| f.slice_before { |line| /\A\S/ === line }.each { |e| pp e } }
“svn proplist -R” produces multiline output for each file. They can be chunked as follows:
IO.popen([{"LC_ALL"=>"C"}, "svn", "proplist", "-R"]) { |f| f.lines.slice_before(/\AProp/).each { |lines| p lines } } #=> ["Properties on '.':\n", " svn:ignore\n", " svk:merge\n"] # ["Properties on 'goruby.c':\n", " svn:eol-style\n"] # ["Properties on 'complex.c':\n", " svn:mime-type\n", " svn:eol-style\n"] # ["Properties on 'regparse.c':\n", " svn:eol-style\n"] # ...
If the block needs to maintain state over multiple elements, local variables can be used. For example, three or more consecutive increasing numbers can be squashed as follows (see chunk_while
for a better way):
a = [0, 2, 3, 4, 6, 7, 9] prev = a[0] p a.slice_before { |e| prev, prev2 = e, prev prev2 + 1 != e }.map { |es| es.length <= 2 ? es.join(",") : "#{es.first}-#{es.last}" }.join(",") #=> "0,2-4,6,7,9"
However local variables should be used carefully if the result enumerator is enumerated twice or more. The local variables should be initialized for each enumeration. Enumerator.new
can be used to do it.
# Word wrapping. This assumes all characters have same width. def wordwrap(words, maxwidth) Enumerator.new {|y| # cols is initialized in Enumerator.new. cols = 0 words.slice_before { |w| cols += 1 if cols != 0 cols += w.length if maxwidth < cols cols = w.length true else false end }.each {|ws| y.yield ws } } end text = (1..20).to_a.join(" ") enum = wordwrap(text.split(/\s+/), 10) puts "-"*10 enum.each { |ws| puts ws.join(" ") } # first enumeration. puts "-"*10 enum.each { |ws| puts ws.join(" ") } # second enumeration generates same result as the first. puts "-"*10 #=> ---------- # 1 2 3 4 5 # 6 7 8 9 10 # 11 12 13 # 14 15 16 # 17 18 19 # 20 # ---------- # 1 2 3 4 5 # 6 7 8 9 10 # 11 12 13 # 14 15 16 # 17 18 19 # 20 # ----------
mbox contains series of mails which start with Unix From line. So each mail can be extracted by slice before Unix From line.
# parse mbox open("mbox") { |f| f.slice_before { |line| line.start_with? "From " }.each { |mail| unix_from = mail.shift i = mail.index("\n") header = mail[0...i] body = mail[(i+1)..-1] body.pop if body.last == "\n" fields = header.slice_before { |line| !" \t".include?(line[0]) }.to_a p unix_from pp fields pp body } } # split mails in mbox (slice before Unix From line after an empty line) open("mbox") { |f| emp = true f.slice_before { |line| prevemp = emp emp = line == "\n" prevemp && line.start_with?("From ") }.each { |mail| mail.pop if mail.last == "\n" pp mail } }
Returns the last Error
of the current executing Thread
or nil if none
Sets the last Error
of the current executing Thread
to error
Parse a YAML string in yaml
. Returns the Psych::Nodes::Stream
. This method can handle multiple YAML documents contained in yaml
. filename
is used in the exception message if a Psych::SyntaxError
is raised.
If a block is given, a Psych::Nodes::Document
node will be yielded to the block as it’s being parsed.
Raises a Psych::SyntaxError
when a YAML syntax error is detected.
Example:
Psych.parse_stream("---\n - a\n - b") # => #<Psych::Nodes::Stream:0x00> Psych.parse_stream("--- a\n--- b") do |node| node # => #<Psych::Nodes::Document:0x00> end begin Psych.parse_stream("--- `", filename: "file.txt") rescue Psych::SyntaxError => ex ex.file # => 'file.txt' ex.message # => "(file.txt): found character that cannot start any token" end
Raises a TypeError
when NilClass
is passed.
See Psych::Nodes
for more information about YAML AST.
Dump a list of objects as separate documents to a document stream.
Example:
Psych.dump_stream("foo\n ", {}) # => "--- ! \"foo\\n \"\n--- {}\n"
Load multiple documents given in yaml
. Returns the parsed documents as a list. If a block is given, each document will be converted to Ruby and passed to the block during parsing
Example:
Psych.load_stream("--- foo\n...\n--- bar\n...") # => ['foo', 'bar'] list = [] Psych.load_stream("--- foo\n...\n--- bar\n...") do |ruby| list << ruby end list # => ['foo', 'bar']
Clear the current input line.
Returns true
if the named file is readable by the real user and group id of this process. See access(3).
If file_name is readable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_readable?("/etc/passwd") #=> 420 m = File.world_readable?("/etc/passwd") sprintf("%o", m) #=> "644"
Adds a post-install hook that will be passed an Gem::Installer
instance when Gem::Installer#install
is called
Adds a hook that will get run after Gem::Specification.reset
is run.