Reads and returns the next character from the stream; see Character IO.
Pushes back (“unshifts”) a character or integer onto the stream; see Character IO.
See IO#putc.
Returns false. Just for compatibility to IO.
Truncates the buffer string to at most integer bytes. The stream must be opened for writing.
Sets the scan pointer to the end of the string and clear matching data.
Appends str to the string being scanned. This method does not affect scan pointer.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.scan(/Fri /) s << " +1000 GMT" s.string # -> "Fri Dec 12 1975 14:39 +1000 GMT" s.scan(/Dec/) # -> "Dec"
Returns the character position of the scan pointer. In the ‘reset’ position, this value is zero. In the ‘terminated’ position (i.e. the string is exhausted), this value is the size of the string.
In short, it’s a 0-based index into the string.
s = StringScanner.new("abc\u00e4def\u00f6ghi") s.charpos # -> 0 s.scan_until(/\u00e4/) # -> "abc\u00E4" s.pos # -> 5 s.charpos # -> 4
This returns the value that scan would return, without advancing the scan pointer. The match register is affected, though.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.check /Fri/ # -> "Fri" s.pos # -> 0 s.matched # -> "Fri" s.check /12/ # -> nil s.matched # -> nil
Mnemonic: it “checks” to see whether a scan will return a value.
Iterates over each item of OLE collection which has IEnumVARIANT interface.
excel = WIN32OLE.new('Excel.Application') book = excel.workbooks.add sheets = book.worksheets(1) cells = sheets.cells("A1:A5") cells.each do |cell| cell.value = 10 end
Hash#each is an alias for Hash#each_pair.
Calls the given block with each key-value pair; returns self:
h = {foo: 0, bar: 1, baz: 2} h.each_pair {|key, value| puts "#{key}: #{value}"} # => {:foo=>0, :bar=>1, :baz=>2}
Output:
foo: 0 bar: 1 baz: 2
Returns a new Enumerator if no block given:
h = {foo: 0, bar: 1, baz: 2} e = h.each_pair # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:each_pair> h1 = e.each {|key, value| puts "#{key}: #{value}"} h1 # => {:foo=>0, :bar=>1, :baz=>2}
Output:
foo: 0 bar: 1 baz: 2
Merges each of other_hashes into self; returns self.
Each argument in other_hashes must be a Hash.
Method update is an alias for #merge!.
With arguments and no block:
Returns self, after the given hashes are merged into it.
The given hashes are merged left to right.
Each new entry is added at the end.
Each duplicate-key entry’s value overwrites the previous value.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h.merge!(h1, h2) # => {:foo=>0, :bar=>4, :baz=>2, :bat=>6, :bam=>5}
With arguments and a block:
Returns self, after the given hashes are merged.
The given hashes are merged left to right.
Each new-key entry is added at the end.
For each duplicate key:
Calls the block with the key and the old and new values.
The block’s return value becomes the new value for the entry.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h3 = h.merge!(h1, h2) { |key, old_value, new_value| old_value + new_value } h3 # => {:foo=>0, :bar=>5, :baz=>2, :bat=>9, :bam=>5}
With no arguments:
Returns self, unmodified.
The block, if given, is ignored.
Example:
h = {foo: 0, bar: 1, baz: 2} h.merge # => {:foo=>0, :bar=>1, :baz=>2} h1 = h.merge! { |key, old_value, new_value| raise 'Cannot happen' } h1 # => {:foo=>0, :bar=>1, :baz=>2}
Returns a new Array object that is a 1-dimensional flattening of self.
By default, nested Arrays are not flattened:
h = {foo: 0, bar: [:bat, 3], baz: 2} h.flatten # => [:foo, 0, :bar, [:bat, 3], :baz, 2]
Takes the depth of recursive flattening from Integer argument level:
h = {foo: 0, bar: [:bat, [:baz, [:bat, ]]]} h.flatten(1) # => [:foo, 0, :bar, [:bat, [:baz, [:bat]]]] h.flatten(2) # => [:foo, 0, :bar, :bat, [:baz, [:bat]]] h.flatten(3) # => [:foo, 0, :bar, :bat, :baz, [:bat]] h.flatten(4) # => [:foo, 0, :bar, :bat, :baz, :bat]
When level is negative, flattens all nested Arrays:
h = {foo: 0, bar: [:bat, [:baz, [:bat, ]]]} h.flatten(-1) # => [:foo, 0, :bar, :bat, :baz, :bat] h.flatten(-2) # => [:foo, 0, :bar, :bat, :baz, :bat]
When level is zero, returns the equivalent of to_a :
h = {foo: 0, bar: [:bat, 3], baz: 2} h.flatten(0) # => [[:foo, 0], [:bar, [:bat, 3]], [:baz, 2]] h.flatten(0) == h.to_a # => true
Yields each environment variable name and its value as a 2-element Array:
h = {} ENV.each_pair { |name, value| h[name] = value } # => ENV h # => {"bar"=>"1", "foo"=>"0"}
Returns an Enumerator if no block given:
h = {} e = ENV.each_pair # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_pair> e.each { |name, value| h[name] = value } # => ENV h # => {"bar"=>"1", "foo"=>"0"}
ENV.update is an alias for ENV.merge!.
Adds to ENV each key/value pair in the given hash; returns ENV:
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('baz' => '2', 'bat' => '3') # => {"bar"=>"1", "bat"=>"3", "baz"=>"2", "foo"=>"0"}
Deletes the ENV entry for a hash value that is nil:
ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}
For an already-existing name, if no block given, overwrites the ENV value:
ENV.merge!('foo' => '4') # => {"bar"=>"1", "foo"=>"4"}
For an already-existing name, if block given, yields the name, its ENV value, and its hash value; the block’s return value becomes the new name:
ENV.merge!('foo' => '5') { |name, env_val, hash_val | env_val + hash_val } # => {"bar"=>"1", "foo"=>"45"}
Raises an exception if a name or value is invalid (see Invalid Names and Values);
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('foo' => '6', :bar => '7', 'baz' => '9') # Raises TypeError (no implicit conversion of Symbol into String) ENV # => {"bar"=>"1", "foo"=>"6"} ENV.merge!('foo' => '7', 'bar' => 8, 'baz' => '9') # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "foo"=>"7"}
Raises an exception if the block returns an invalid name: (see Invalid Names and Values):
ENV.merge!('bat' => '8', 'foo' => '9') { |name, env_val, hash_val | 10 } # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "bat"=>"8", "foo"=>"7"}
Note that for the exceptions above, hash pairs preceding an invalid name or value are processed normally; those following are ignored.
Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is an Integer specifying the maximum length of each line; longer lines will be split according to this limit.
This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename of the current line and line number of the whole input, respectively.
For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:
ARGF.each_line do |line| puts ARGF.filename if ARGF.file.lineno == 1 puts "#{ARGF.file.lineno}: #{line}" end
While the following code prints only the first file’s name at first, and the contents with line number counted through all named files.
ARGF.each_line do |line| puts ARGF.filename if ARGF.lineno == 1 puts "#{ARGF.lineno}: #{line}" end
Reads the next character from ARGF and returns it as a String. Returns nil at the end of the stream.
ARGF treats the files named on the command line as a single file created by concatenating their contents. After returning the last character of the first file, it returns the first character of the second file, and so on.
For example:
$ echo "foo" > file $ ruby argf.rb file ARGF.getc #=> "f" ARGF.getc #=> "o" ARGF.getc #=> "o" ARGF.getc #=> "\n" ARGF.getc #=> nil ARGF.getc #=> nil
Reads the next character from ARGF and returns it as a String. Raises an EOFError after the last character of the last file has been read.
For example:
$ echo "foo" > file $ ruby argf.rb file ARGF.readchar #=> "f" ARGF.readchar #=> "o" ARGF.readchar #=> "o" ARGF.readchar #=> "\n" ARGF.readchar #=> end of file reached (EOFError)
Writes a character to the stream. See Character IO.
If object is numeric, converts to integer if necessary, then writes the character whose code is the least significant byte; if object is a string, writes the first character:
$stdout.putc "A" $stdout.putc 65
Output:
AA
Returns the current filename. “-” is returned when the current file is STDIN.
For example:
$ echo "foo" > foo $ echo "bar" > bar $ echo "glark" > glark $ ruby argf.rb foo bar glark ARGF.filename #=> "foo" ARGF.read(5) #=> "foo\nb" ARGF.filename #=> "bar" ARGF.skip ARGF.filename #=> "glark"
Calls the block with each row read from source path_or_io.
Path input without headers:
string = "foo,0\nbar,1\nbaz,2\n" in_path = 't.csv' File.write(in_path, string) CSV.foreach(in_path) {|row| p row }
Output:
["foo", "0"] ["bar", "1"] ["baz", "2"]
Path input with headers:
string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" in_path = 't.csv' File.write(in_path, string) CSV.foreach(in_path, headers: true) {|row| p row }
Output:
<CSV::Row "Name":"foo" "Value":"0"> <CSV::Row "Name":"bar" "Value":"1"> <CSV::Row "Name":"baz" "Value":"2">
IO stream input without headers:
string = "foo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string) File.open('t.csv') do |in_io| CSV.foreach(in_io) {|row| p row } end
Output:
["foo", "0"] ["bar", "1"] ["baz", "2"]
IO stream input with headers:
string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string) File.open('t.csv') do |in_io| CSV.foreach(in_io, headers: true) {|row| p row } end
Output:
<CSV::Row "Name":"foo" "Value":"0"> <CSV::Row "Name":"bar" "Value":"1"> <CSV::Row "Name":"baz" "Value":"2">
With no block given, returns an Enumerator:
string = "foo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string) CSV.foreach(path) # => #<Enumerator: CSV:foreach("t.csv", "r")>
Arguments:
Argument path_or_io must be a file path or an IO stream.
Argument mode, if given, must be a File mode See Open Mode.
Arguments **options must be keyword options. See Options for Parsing.
This method optionally accepts an additional :encoding option that you can use to specify the Encoding of the data read from path or io. You must provide this unless your data is in the encoding given by Encoding::default_external. Parsing will use this to determine how to parse the data. You may provide a second Encoding to have the data transcoded as it is read. For example,
encoding: 'UTF-32BE:UTF-8'
would read UTF-32BE data from the file but transcode it to UTF-8 before parsing.
Argument csv_string, if given, must be a String object; defaults to a new empty String.
Arguments options, if given, should be generating options. See Options for Generating.
Creates a new CSV object via CSV.new(csv_string, **options); calls the block with the CSV object, which the block may modify; returns the String generated from the CSV object.
Note that a passed String is modified by this method. Pass csv_string.dup if the String must be preserved.
This method has one additional option: :encoding, which sets the base Encoding for the output if no no str is specified. CSV needs this hint if you plan to output non-ASCII compatible data.
Add lines:
input_string = "foo,0\nbar,1\nbaz,2\n" output_string = CSV.generate(input_string) do |csv| csv << ['bat', 3] csv << ['bam', 4] end output_string # => "foo,0\nbar,1\nbaz,2\nbat,3\nbam,4\n" input_string # => "foo,0\nbar,1\nbaz,2\nbat,3\nbam,4\n" output_string.equal?(input_string) # => true # Same string, modified
Add lines into new string, preserving old string:
input_string = "foo,0\nbar,1\nbaz,2\n" output_string = CSV.generate(input_string.dup) do |csv| csv << ['bat', 3] csv << ['bam', 4] end output_string # => "foo,0\nbar,1\nbaz,2\nbat,3\nbam,4\n" input_string # => "foo,0\nbar,1\nbaz,2\n" output_string.equal?(input_string) # => false # Different strings
Create lines from nothing:
output_string = CSV.generate do |csv| csv << ['foo', 0] csv << ['bar', 1] csv << ['baz', 2] end output_string # => "foo,0\nbar,1\nbaz,2\n"
Raises an exception if csv_string is not a String object:
# Raises TypeError (no implicit conversion of Integer into String) CSV.generate(0)
Calls the block with each successive row. The data source must be opened for reading.
Without headers:
string = "foo,0\nbar,1\nbaz,2\n" csv = CSV.new(string) csv.each do |row| p row end
Output:
["foo", "0"] ["bar", "1"] ["baz", "2"]
With headers:
string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" csv = CSV.new(string, headers: true) csv.each do |row| p row end
Output:
<CSV::Row "Name":"foo" "Value":"0"> <CSV::Row "Name":"bar" "Value":"1"> <CSV::Row "Name":"baz" "Value":"2">
Raises an exception if the source is not opened for reading:
string = "foo,0\nbar,1\nbaz,2\n" csv = CSV.new(string) csv.close # Raises IOError (not opened for reading) csv.each do |row| p row end