Generate results and print them. (see ERB#result)
Log an UNKNOWN message. This will be printed no matter what the logger’s level is.
See info for more information.
Returns a matrix with entries rounded to the given precision (see Float#round)
Returns a vector with entries rounded to the given precision (see Float#round)
Returns the modulus (Pythagorean distance) of the vector.
Vector[5,8,2].r => 9.643650761
Returns the smallest number than or equal to int in decimal digits (default 0 digits).
Precision may be negative. Returns a floating point number when ndigits is positive, self for zero, and truncate up for negative.
1.truncate #=> 1 1.truncate(2) #=> 1.0 15.truncate(-1) #=> 10
Rounds int to a given precision in decimal digits (default 0 digits).
Precision may be negative. Returns a floating point number when ndigits is positive, self for zero, and round down for negative.
1.round #=> 1 1.round(2) #=> 1.0 15.round(-1) #=> 20
Returns the absolute value of int.
-12345.abs #=> 12345 12345.abs #=> 12345 -1234567890987654321.abs #=> 1234567890987654321
Unlinks (deletes) the file from the filesystem. One should always unlink the file after using it, as is explained in the “Explicit close” good practice section in the Tempfile overview:
file = Tempfile.new('foo')
begin
...do something with file...
ensure
file.close
file.unlink # deletes the temp file
end
On POSIX systems it’s possible to unlink a file before closing it. This practice is explained in detail in the Tempfile overview (section “Unlink after creation”); please refer there for more information.
However, unlink-before-close may not be supported on non-POSIX operating systems. Microsoft Windows is the most notable case: unlinking a non-closed file will result in an error, which this method will silently ignore. If you want to practice unlink-before-close whenever possible, then you should write code like this:
file = Tempfile.new('foo')
file.unlink # On Windows this silently fails.
begin
... do something with file ...
ensure
file.close! # Closes the file handle. If the file wasn't unlinked
# because #unlink failed, then this method will attempt
# to do so again.
end
Returns true if any thread has terminated and is ready to be collected.
Returns true if any thread has terminated and is ready to be collected.
Wakes up thr, making it eligible for scheduling.
a = Thread.new { puts "a"; Thread.stop; puts "c" } sleep 0.1 while a.status!='sleep' puts "Got here" a.run a.join
This will produce:
a Got here c
See also the instance method wakeup.
Dissociates meth from its current receiver. The resulting UnboundMethod can subsequently be bound to a new object of the same class (see UnboundMethod).
Returns the number of items in enum through enumeration. If an argument is given, the number of items in enum that are equal to item are counted. If a block is given, it counts the number of elements yielding a true value.
ary = [1, 2, 4, 2] ary.count #=> 4 ary.count(2) #=> 2 ary.count{ |x| x%2==0 } #=> 3
Enumerates over the items, chunking them together based on the return value of the block.
Consecutive elements which return the same block value are chunked together.
For example, consecutive even numbers and odd numbers can be chunked as follows.
[3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5].chunk { |n| n.even? }.each { |even, ary| p [even, ary] } #=> [false, [3, 1]] # [true, [4]] # [false, [1, 5, 9]] # [true, [2, 6]] # [false, [5, 3, 5]]
This method is especially useful for sorted series of elements. The following example counts words for each initial letter.
open("/usr/share/dict/words", "r:iso-8859-1") { |f| f.chunk { |line| line.ord }.each { |ch, lines| p [ch.chr, lines.length] } } #=> ["\n", 1] # ["A", 1327] # ["B", 1372] # ["C", 1507] # ["D", 791] # ...
The following key values have special meaning:
nil and :_separator specifies that the elements should be dropped.
:_alone specifies that the element should be chunked by itself.
Any other symbols that begin with an underscore will raise an error:
items.chunk { |item| :_underscore } #=> RuntimeError: symbols beginning with an underscore are reserved
nil and :_separator can be used to ignore some elements.
For example, the sequence of hyphens in svn log can be eliminated as follows:
sep = "-"*72 + "\n" IO.popen("svn log README") { |f| f.chunk { |line| line != sep || nil }.each { |_, lines| pp lines } } #=> ["r20018 | knu | 2008-10-29 13:20:42 +0900 (Wed, 29 Oct 2008) | 2 lines\n", # "\n", # "* README, README.ja: Update the portability section.\n", # "\n"] # ["r16725 | knu | 2008-05-31 23:34:23 +0900 (Sat, 31 May 2008) | 2 lines\n", # "\n", # "* README, README.ja: Add a note about default C flags.\n", # "\n"] # ...
Paragraphs separated by empty lines can be parsed as follows:
File.foreach("README").chunk { |line| /\A\s*\z/ !~ line || nil }.each { |_, lines| pp lines }
:_alone can be used to force items into their own chunk. For example, you can put lines that contain a URL by themselves, and chunk the rest of the lines together, like this:
pattern = /http/ open(filename) { |f| f.chunk { |line| line =~ pattern ? :_alone : true }.each { |key, lines| pp lines } }
If no block is given, an enumerator to ‘chunk` is returned instead.
Returns the system information obtained by uname system call.
The return value is a hash which has 5 keys at least:
:sysname, :nodename, :release, :version, :machine
Example:
require 'etc' require 'pp' pp Etc.uname #=> {:sysname=>"Linux", # :nodename=>"boron", # :release=>"2.6.18-6-xen-686", # :version=>"#1 SMP Thu Nov 5 19:54:42 UTC 2009", # :machine=>"i686"}
Returns the hexadecimal representation of a memory pointer address addr
Example:
lib = Fiddle.dlopen('/lib64/libc-2.15.so')
=> #<Fiddle::Handle:0x00000001342460>
lib['strcpy'].to_s(16)
=> "7f59de6dd240"
Fiddle.dlunwrap(Fiddle.dlwrap(lib['strcpy'].to_s(16)))
=> "7f59de6dd240"
Decode the given gzipped string.
This method is almost equivalent to the following code:
def gunzip(string) sio = StringIO.new(string) gz = Zlib::GzipReader.new(sio, encoding: Encoding::ASCII_8BIT) gz.read ensure gz&.close end
See also Zlib.gzip
The number of times GC occurred.
It returns the number of times GC occurred since the process started.
Skips the current file or directory, restarting the loop with the next entry. If the current file is a directory, that directory will not be recursively entered. Meaningful only within the block associated with Find::find.
See the Find module documentation for an example.
Skips the current file or directory, restarting the loop with the next entry. If the current file is a directory, that directory will not be recursively entered. Meaningful only within the block associated with Find::find.
See the Find module documentation for an example.
Zlib::GzipReader wrapper that unzips data.
Initializes the supplemental group access list by reading the system group database and using all groups of which the given user is a member. The group with the specified gid is also added to the list. Returns the resulting Array of the gids of all the groups in the supplementary group access list. Not available on all platforms.
Process.groups #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27] Process.initgroups( "mgranger", 30 ) #=> [30, 6, 10, 11] Process.groups #=> [30, 6, 10, 11]