Puts option summary into to
and returns to
. Yields each line if a block is given.
to
Output destination, which must have method <<. Defaults to [].
width
Width of left side, defaults to @summary_width.
max
Maximum length allowed for left side, defaults to width
- 1.
indent
Indentation, defaults to @summary_indent.
Add separator in summary.
Return candidates for word
.
Parses environment variable env
or its uppercase with splitting like a shell.
env
defaults to the basename of the program.
Returns the full path name of the temporary file. This will be nil if unlink
has been called.
Creates a file in the underlying file system; returns a new File object based on that file.
With no block given and no arguments, creates and returns file whose:
Directory is the system temporary directory (system-dependent).
Generated filename is unique in that directory.
Permissions are 0600
; see File Permissions.
Mode is 'w+'
(read/write mode, positioned at the end).
The temporary file removal depends on the keyword argument anonymous
and whether a block is given or not. See the description about the anonymous
keyword argument later.
Example:
f = Tempfile.create # => #<File:/tmp/20220505-9795-17ky6f6> f.class # => File f.path # => "/tmp/20220505-9795-17ky6f6" f.stat.mode.to_s(8) # => "100600" f.close File.exist?(f.path) # => true File.unlink(f.path) File.exist?(f.path) # => false Tempfile.create {|f| f.puts "foo" f.rewind f.read # => "foo\n" f.path # => "/tmp/20240524-380207-oma0ny" File.exist?(f.path) # => true } # The file is removed at block exit. f = Tempfile.create(anonymous: true) # The file is already removed because anonymous f.path # => "/tmp/" (no filename since no file) f.puts "foo" f.rewind f.read # => "foo\n" f.close Tempfile.create(anonymous: true) {|f| # The file is already removed because anonymous f.path # => "/tmp/" (no filename since no file) f.puts "foo" f.rewind f.read # => "foo\n" }
The argument basename
, if given, may be one of the following:
A string: the generated filename begins with basename
:
Tempfile.create('foo') # => #<File:/tmp/foo20220505-9795-1gok8l9>
An array of two strings [prefix, suffix]
: the generated filename begins with prefix
and ends with suffix
:
Tempfile.create(%w/foo .jpg/) # => #<File:/tmp/foo20220505-17839-tnjchh.jpg>
With arguments basename
and tmpdir
, the file is created in the directory tmpdir
:
Tempfile.create('foo', '.') # => #<File:./foo20220505-9795-1emu6g8>
Keyword arguments mode
and options
are passed directly to the method File.open
:
The value given for mode
must be an integer and may be expressed as the logical OR of constants defined in File::Constants
.
For options
, see Open Options.
The keyword argument anonymous
specifies when the file is removed.
anonymous=false
(default) without a block: the file is not removed.
anonymous=false
(default) with a block: the file is removed after the block exits.
anonymous=true
without a block: the file is removed before returning.
anonymous=true
with a block: the file is removed before the block is called.
In the first case (anonymous=false
without a block), the file is not removed automatically. It should be explicitly closed. It can be used to rename to the desired filename. If the file is not needed, it should be explicitly removed.
The File#path
method of the created file object returns the temporary directory with a trailing slash when anonymous
is true.
When a block is given, it creates the file as described above, passes it to the block, and returns the block’s value. Before the returning, the file object is closed and the underlying file is removed:
Tempfile.create {|file| file.path } # => "/tmp/20220505-9795-rkists"
Implementation note:
The keyword argument +anonymous=true+ is implemented using FILE_SHARE_DELETE on Windows. O_TMPFILE is used on Linux.
Related: Tempfile.new
.
returns main ractor
Returns the main thread.
Terminates thr
and schedules another thread to be run, returning the terminated Thread
. If this is the main thread, or the last thread, exits the process.
Returns the status of thr
.
"sleep"
Returned if this thread is sleeping or waiting on I/O
"run"
When this thread is executing
"aborting"
If this thread is aborting
false
When this thread is terminated normally
nil
If terminated with an exception.
a = Thread.new { raise("die now") } b = Thread.new { Thread.stop } c = Thread.new { Thread.exit } d = Thread.new { sleep } d.kill #=> #<Thread:0x401b3678 aborting> a.status #=> nil b.status #=> "sleep" c.status #=> false d.status #=> "aborting" Thread.current.status #=> "run"
Returns internal information of TracePoint
.
The contents of the returned value are implementation specific. It may be changed in future.
This method is only for debugging TracePoint
itself.
Path of the file being run
Creates a new Pathname
object from the given string, path
, and returns pathname object.
In order to use this constructor, you must first require the Pathname
standard library extension.
require 'pathname' Pathname("/home/zzak") #=> #<Pathname:/home/zzak>
See also Pathname::new
for more information.
Equivalent to:
$stdout.putc(int)
See IO#putc
for important information regarding multi-byte characters.
Returns arg converted to a float. Numeric
types are converted directly, and with exception to String
and nil
the rest are converted using arg.to_f
. Converting a String
with invalid characters will result in a ArgumentError
. Converting nil
generates a TypeError
. Exceptions can be suppressed by passing exception: false
.
Float(1) #=> 1.0 Float("123.456") #=> 123.456 Float("123.0_badstring") #=> ArgumentError: invalid value for Float(): "123.0_badstring" Float(nil) #=> TypeError: can't convert nil into Float Float("123.0_badstring", exception: false) #=> nil
Returns x/y
or arg
as a Rational
.
Rational(2, 3) #=> (2/3) Rational(5) #=> (5/1) Rational(0.5) #=> (1/2) Rational(0.3) #=> (5404319552844595/18014398509481984) Rational("2/3") #=> (2/3) Rational("0.3") #=> (3/10) Rational("10 cents") #=> ArgumentError Rational(nil) #=> TypeError Rational(1, nil) #=> TypeError Rational("10 cents", exception: false) #=> nil
Syntax of the string form:
string form = extra spaces , rational , extra spaces ; rational = [ sign ] , unsigned rational ; unsigned rational = numerator | numerator , "/" , denominator ; numerator = integer part | fractional part | integer part , fractional part ; denominator = digits ; integer part = digits ; fractional part = "." , digits , [ ( "e" | "E" ) , [ sign ] , digits ] ; sign = "-" | "+" ; digits = digit , { digit | "_" , digit } ; digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ; extra spaces = ? \s* ? ;
See also String#to_r
.
Equivalent to ($_.dup).chop!
, except nil
is never returned. See String#chop!
. Available only when -p/-n command line option specified.
Equivalent to $_ = $_.chomp(string)
. See String#chomp
. Available only when -p/-n command line option specified.
Deprecated. Use block_given? instead.
Returns an array of objects returned by the block.
With a block given, calls the block with successive elements; returns an array of the objects returned by the block:
(0..4).map {|i| i*i } # => [0, 1, 4, 9, 16] {foo: 0, bar: 1, baz: 2}.map {|key, value| value*2} # => [0, 2, 4]
With no block given, returns an Enumerator
.
Returns the element with the maximum element according to a given criterion. The ordering of equal elements is indeterminate and may be unstable.
With no argument and no block, returns the maximum element, using the elements’ own method <=>
for comparison:
(1..4).max # => 4 (-4..-1).max # => -1 %w[d c b a].max # => "d" {foo: 0, bar: 1, baz: 2}.max # => [:foo, 0] [].max # => nil
With positive integer argument n
given, and no block, returns an array containing the first n
maximum elements that exist:
(1..4).max(2) # => [4, 3] (-4..-1).max(2) # => [-1, -2] %w[d c b a].max(2) # => ["d", "c"] {foo: 0, bar: 1, baz: 2}.max(2) # => [[:foo, 0], [:baz, 2]] [].max(2) # => []
With a block given, the block determines the maximum elements. The block is called with two elements a
and b
, and must return:
A negative integer if a < b
.
Zero if a == b
.
A positive integer if a > b
.
With a block given and no argument, returns the maximum element as determined by the block:
%w[xxx x xxxx xx].max {|a, b| a.size <=> b.size } # => "xxxx" h = {foo: 0, bar: 1, baz: 2} h.max {|pair1, pair2| pair1[1] <=> pair2[1] } # => [:baz, 2] [].max {|a, b| a <=> b } # => nil
With a block given and positive integer argument n
given, returns an array containing the first n
maximum elements that exist, as determined by the block.
%w[xxx x xxxx xx].max(2) {|a, b| a.size <=> b.size } # => ["xxxx", "xxx"] h = {foo: 0, bar: 1, baz: 2} h.max(2) {|pair1, pair2| pair1[1] <=> pair2[1] } # => [[:baz, 2], [:bar, 1]] [].max(2) {|a, b| a <=> b } # => []
Each element in the returned enumerator is a 2-element array consisting of:
A value returned by the block.
An array (“chunk”) containing the element for which that value was returned, and all following elements for which the block returned the same value:
So that:
Each block return value that is different from its predecessor begins a new chunk.
Each block return value that is the same as its predecessor continues the same chunk.
Example:
e = (0..10).chunk {|i| (i / 3).floor } # => #<Enumerator: ...> # The enumerator elements. e.next # => [0, [0, 1, 2]] e.next # => [1, [3, 4, 5]] e.next # => [2, [6, 7, 8]] e.next # => [3, [9, 10]]
Method chunk
is especially useful for an enumerable that is already sorted. This example counts words for each initial letter in a large array of words:
# Get sorted words from a web page. url = 'https://raw.githubusercontent.com/eneko/data-repository/master/data/words.txt' words = URI::open(url).readlines # Make chunks, one for each letter. e = words.chunk {|word| word.upcase[0] } # => #<Enumerator: ...> # Display 'A' through 'F'. e.each {|c, words| p [c, words.length]; break if c == 'F' }
Output:
["A", 17096] ["B", 11070] ["C", 19901] ["D", 10896] ["E", 8736] ["F", 6860]
You can use the special symbol :_alone
to force an element into its own separate chuck:
a = [0, 0, 1, 1] e = a.chunk{|i| i.even? ? :_alone : true } e.to_a # => [[:_alone, [0]], [:_alone, [0]], [true, [1, 1]]]
For example, you can put each line that contains a URL into its own chunk:
pattern = /http/ open(filename) { |f| f.chunk { |line| line =~ pattern ? :_alone : true }.each { |key, lines| pp lines } }
You can use the special symbol :_separator
or nil
to force an element to be ignored (not included in any chunk):
a = [0, 0, -1, 1, 1] e = a.chunk{|i| i < 0 ? :_separator : true } e.to_a # => [[true, [0, 0]], [true, [1, 1]]]
Note that the separator does end the chunk:
a = [0, 0, -1, 1, -1, 1] e = a.chunk{|i| i < 0 ? :_separator : true } e.to_a # => [[true, [0, 0]], [true, [1]], [true, [1]]]
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 }
Returns an enumerator object generated from this enumerator and given enumerables.
e = (1..3).chain([4, 5]) e.to_a #=> [1, 2, 3, 4, 5]
Returns a list of the supported category symbols.