Results for: "Dir.chdir"

Kernel#chomp

Equivalent to $_ = $_.chomp(string). See String#chomp. Available only when -p/-n command line option specified.

Kernel#catch

catch executes its block. If throw is not called, the block executes normally, and catch returns the value of the last expression evaluated.

catch(1) { 123 }            # => 123

If throw(tag2, val) is called, Ruby searches up its stack for a catch block whose tag has the same object_id as tag2. When found, the block stops executing and returns val (or nil if no second argument was given to throw).

catch(1) { throw(1, 456) }  # => 456
catch(1) { throw(1) }       # => nil

When tag is passed as the first argument, catch yields it as the parameter of the block.

catch(1) {|x| x + 2 }       # => 3

When no tag is given, catch yields a new unique object (as from Object.new) as the block parameter. This object can then be used as the argument to throw, and will match the correct catch block.

catch do |obj_A|
  catch do |obj_B|
    throw(obj_B, 123)
    puts "This puts is not reached"
  end

  puts "This puts is displayed"
  456
end

# => 456

catch do |obj_A|
  catch do |obj_B|
    throw(obj_A, 123)
    puts "This puts is still not reached"
  end

  puts "Now this puts is also not reached"
  456
end

# => 123

Enumerable#chunk

Each element in the returned enumerator is a 2-element array consisting of:

So that:

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
}

Enumerable#chain

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]

MonitorMixin#synchronize

No documentation available

FileTest#chardev?

Returns true if filepath points to a character device, false otherwise.

File.chardev?($stdin)     # => true
File.chardev?('t.txt')     # => false

Benchmark#benchmark

Invokes the block with a Benchmark::Report object, which may be used to collect and report on the results of individual benchmark tests. Reserves label_width leading spaces for labels on each line. Prints caption at the top of the report, and uses format to format each line. (Note: caption must contain a terminating newline character, see the default Benchmark::Tms::CAPTION for an example.)

Returns an array of Benchmark::Tms objects.

If the block returns an array of Benchmark::Tms objects, these will be used to format additional lines of output. If labels parameter are given, these are used to label these extra lines.

Note: Other methods provide a simpler interface to this one, and are suitable for nearly all benchmarking requirements. See the examples in Benchmark, and the bm and bmbm methods.

Example:

require 'benchmark'
include Benchmark          # we need the CAPTION and FORMAT constants

n = 5000000
Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x|
  tf = x.report("for:")   { for i in 1..n; a = "1"; end }
  tt = x.report("times:") { n.times do   ; a = "1"; end }
  tu = x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
  [tf+tt+tu, (tf+tt+tu)/3]
end

Generates:

              user     system      total        real
for:      0.970000   0.000000   0.970000 (  0.970493)
times:    0.990000   0.000000   0.990000 (  0.989542)
upto:     0.970000   0.000000   0.970000 (  0.972854)
>total:   2.930000   0.000000   2.930000 (  2.932889)
>avg:     0.976667   0.000000   0.976667 (  0.977630)

Benchmark::benchmark

Invokes the block with a Benchmark::Report object, which may be used to collect and report on the results of individual benchmark tests. Reserves label_width leading spaces for labels on each line. Prints caption at the top of the report, and uses format to format each line. (Note: caption must contain a terminating newline character, see the default Benchmark::Tms::CAPTION for an example.)

Returns an array of Benchmark::Tms objects.

If the block returns an array of Benchmark::Tms objects, these will be used to format additional lines of output. If labels parameter are given, these are used to label these extra lines.

Note: Other methods provide a simpler interface to this one, and are suitable for nearly all benchmarking requirements. See the examples in Benchmark, and the bm and bmbm methods.

Example:

require 'benchmark'
include Benchmark          # we need the CAPTION and FORMAT constants

n = 5000000
Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x|
  tf = x.report("for:")   { for i in 1..n; a = "1"; end }
  tt = x.report("times:") { n.times do   ; a = "1"; end }
  tu = x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
  [tf+tt+tu, (tf+tt+tu)/3]
end

Generates:

              user     system      total        real
for:      0.970000   0.000000   0.970000 (  0.970493)
times:    0.990000   0.000000   0.990000 (  0.989542)
upto:     0.970000   0.000000   0.970000 (  0.972854)
>total:   2.930000   0.000000   2.930000 (  2.932889)
>avg:     0.976667   0.000000   0.976667 (  0.977630)

FileUtils#chmod

Changes permissions on the entries at the paths given in list (a single path or an array of paths) to the permissions given by mode; returns list if it is an array, [list] otherwise:

Argument list or its elements should be interpretable as paths.

Argument mode may be either an integer or a string:

Keyword arguments:

Related: FileUtils.chmod_R.

FileUtils::chmod

Changes permissions on the entries at the paths given in list (a single path or an array of paths) to the permissions given by mode; returns list if it is an array, [list] otherwise:

Argument list or its elements should be interpretable as paths.

Argument mode may be either an integer or a string:

Keyword arguments:

Related: FileUtils.chmod_R.

FileUtils#chmod_R

Like FileUtils.chmod, but changes permissions recursively.

FileUtils::chmod_R

Like FileUtils.chmod, but changes permissions recursively.

FileUtils#chown

Changes the owner and group on the entries at the paths given in list (a single path or an array of paths) to the given user and group; returns list if it is an array, [list] otherwise:

Argument list or its elements should be interpretable as paths.

User and group:

Examples:

# One path.
# User and group as string names.
File.stat('src0.txt').uid # => 1004
File.stat('src0.txt').gid # => 1004
FileUtils.chown('user2', 'group1', 'src0.txt')
File.stat('src0.txt').uid # => 1006
File.stat('src0.txt').gid # => 1005

# User and group as uid and gid.
FileUtils.chown(1004, 1004, 'src0.txt')
File.stat('src0.txt').uid # => 1004
File.stat('src0.txt').gid # => 1004

# Array of paths.
FileUtils.chown(1006, 1005, ['src0.txt', 'src0.dat'])

# Directory (not recursive).
FileUtils.chown('user2', 'group1', '.')

Keyword arguments:

Related: FileUtils.chown_R.

FileUtils::chown

Changes the owner and group on the entries at the paths given in list (a single path or an array of paths) to the given user and group; returns list if it is an array, [list] otherwise:

Argument list or its elements should be interpretable as paths.

User and group:

Examples:

# One path.
# User and group as string names.
File.stat('src0.txt').uid # => 1004
File.stat('src0.txt').gid # => 1004
FileUtils.chown('user2', 'group1', 'src0.txt')
File.stat('src0.txt').uid # => 1006
File.stat('src0.txt').gid # => 1005

# User and group as uid and gid.
FileUtils.chown(1004, 1004, 'src0.txt')
File.stat('src0.txt').uid # => 1004
File.stat('src0.txt').gid # => 1004

# Array of paths.
FileUtils.chown(1006, 1005, ['src0.txt', 'src0.dat'])

# Directory (not recursive).
FileUtils.chown('user2', 'group1', '.')

Keyword arguments:

Related: FileUtils.chown_R.

FileUtils#chown_R

Like FileUtils.chown, but changes owner and group recursively.

FileUtils::chown_R

Like FileUtils.chown, but changes owner and group recursively.

FileUtils#touch

Updates modification times (mtime) and access times (atime) of the entries given by the paths in list (a single path or an array of paths); returns list if it is an array, [list] otherwise.

By default, creates an empty file for any path to a non-existent entry; use keyword argument nocreate to raise an exception instead.

Argument list or its elements should be interpretable as paths.

Examples:

# Single path.
f = File.new('src0.txt') # Existing file.
f.atime # => 2022-06-10 11:11:21.200277 -0700
f.mtime # => 2022-06-10 11:11:21.200277 -0700
FileUtils.touch('src0.txt')
f = File.new('src0.txt')
f.atime # => 2022-06-11 08:28:09.8185343 -0700
f.mtime # => 2022-06-11 08:28:09.8185343 -0700

# Array of paths.
FileUtils.touch(['src0.txt', 'src0.dat'])

Keyword arguments:

Related: FileUtils.uptodate?.

FileUtils::touch

Updates modification times (mtime) and access times (atime) of the entries given by the paths in list (a single path or an array of paths); returns list if it is an array, [list] otherwise.

By default, creates an empty file for any path to a non-existent entry; use keyword argument nocreate to raise an exception instead.

Argument list or its elements should be interpretable as paths.

Examples:

# Single path.
f = File.new('src0.txt') # Existing file.
f.atime # => 2022-06-10 11:11:21.200277 -0700
f.mtime # => 2022-06-10 11:11:21.200277 -0700
FileUtils.touch('src0.txt')
f = File.new('src0.txt')
f.atime # => 2022-06-11 08:28:09.8185343 -0700
f.mtime # => 2022-06-11 08:28:09.8185343 -0700

# Array of paths.
FileUtils.touch(['src0.txt', 'src0.dat'])

Keyword arguments:

Related: FileUtils.uptodate?.

Process::detach

Avoids the potential for a child process to become a zombie process. Process.detach prevents this by setting up a separate Ruby thread whose sole job is to reap the status of the process pid when it terminates.

This method is needed only when the parent process will never wait for the child process.

This example does not reap the second child process; that process appears as a zombie in the process status (ps) output:

pid = Process.spawn('ruby', '-e', 'exit 13') # => 312691
sleep(1)
# Find zombies.
system("ps -ho pid,state -p #{pid}")

Output:

312716 Z

This example also does not reap the second child process, but it does detach the process so that it does not become a zombie:

pid = Process.spawn('ruby', '-e', 'exit 13') # => 313213
thread = Process.detach(pid)
sleep(1)
# => #<Process::Waiter:0x00007f038f48b838 run>
system("ps -ho pid,state -p #{pid}")        # Finds no zombies.

The waiting thread can return the pid of the detached child process:

thread.join.pid                       # => 313262

Reline::Config#add_oneshot_key_binding

No documentation available

Reline::Config#reset_oneshot_key_bindings

No documentation available

Reline::Config#add_default_key_binding

No documentation available

Reline::ANSI#set_default_key_bindings

No documentation available

Reline::Dumb#set_default_key_bindings

No documentation available

Reline::Windows#set_default_key_bindings

No documentation available
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