IO.copy_stream copies src to dst. src and dst is either a filename or an IO-like object. IO-like object for src should have readpartial or read method. IO-like object for dst should have write method. (Specialized mechanisms, such as sendfile system call, may be used on appropriate situation.)
This method returns the number of bytes copied.
If optional arguments are not given, the start position of the copy is the beginning of the filename or the current file offset of the IO. The end position of the copy is the end of file.
If copy_length is given, No more than copy_length bytes are copied.
If src_offset is given, it specifies the start position of the copy.
When src_offset is specified and src is an IO, IO.copy_stream doesn’t move the current file offset.
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.
Returns the status of the global “ignore deadlock” condition. The default is false, so that deadlock conditions are not ignored.
See also ::ignore_deadlock=.
Returns the new state. When set to true, the VM will not check for deadlock conditions. It is only useful to set this if your application can break a deadlock condition via some other means, such as a signal.
Thread.ignore_deadlock = true queue = Queue.new trap(:SIGUSR1){queue.push "Received signal"} # raises fatal error unless ignoring deadlock puts queue.pop
See also ::ignore_deadlock.
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
Constant time memory comparison. Inputs are hashed using SHA-256 to mask the length of the secret. Returns true if the strings are identical, false otherwise.
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"