Unary Plus. Alternate form of a

 rio('f1') > rio('f2')     # copy f1 to f2
 rio('f1') > rio('f2').a   # append f1 to f2
 rio('f1') > +rio('f2')    # same thing
 rio('f1') >> rio('f2')    # same thing

Sets the implicit output mode to ‘a’.

This is the mode Rio will use for output when no mode is specified

Rios normally don’t need to be opened or have their open mode specified. A Rio determines the mode based on the file system object and on the action specified. For instance when a Rio encounters a read on a file it opens the file for reading using File#open and calls IO#read; when it encounters a read on a directory it knows to use Dir#open and call Dir#read. When it encounters a puts, it knows to perform a File#open, and call IO#puts on the returned handle. By default when a method requires a file be opened for writing the file is opened with a mode of ‘w’. a changes this implicit output mode to ‘a’.

Note that this is not the same as setting the output mode explicitly, as in rio(‘afile’).mode(‘a’). When the mode is set explicitly using mode, the mode specified will be used regardless of the operation being performed. The a method only affects how Rio opens a file when it sees an operator that requires writing, and must determine for itself how to open it.

 rio('afile').puts!('Hello World') # call IO#puts on a file handle opened in 'w' mode
 rio('afile').a.puts!('Hello World') # call IO#puts on a file handle opened in 'a' mode

See also a!, w! for setting the implicit output mode ‘a+’ and ‘w+’ respectively

The methods a, a!, w, w!, r, r! set the implicit open mode to ‘a’,’a+’,’w’,’w+’,’r’ and ‘r+’ respectively.

See also +@

Sets the implicit output mode to ‘a+’.

The implicit output mode is the mode Rio will use for output when no mode is specified.

Returns the Rio

See the discussion for a.

Sets the rio to read bytes and returns the rio

n specifies the number of bytes to be returned on each iteration of each or by getrec. If args are provided, they are treated as record selectors as if ario.bytes(n).records(*args) had been called. See also records, lines, each, []

If called with a block behaves as if ario.bytes(n,*args).each(&block) had been called

 rio('f.dat').bytes(1024) { |rec| ... }      # iterate through f.txt 1024 bytes at a time
 rio('f.dat').bytes(1024).each { |rec| ... } # same as above

 rio('f.dat').bytes(1024,0..4) { |rec| ... } # iterate through the first five 1024 byte blocks

 rio('f.dat').bytes(64).to_a # return the contents of f.dat as an array of 64 byte chunks

 rio('f.dat').bytes(512).records(0,7..9) > rio('dfile.dat') # copy 512-byte blocks 0,7,8 and 9 to dfile.dat

 rio('f.dat').bytes(2048).records[0...10] # return an array containing the first 10 2K blocks of f.dat
 rio('f.dat').bytes(2048)[0...10]         # same thing

 rio('f.dat').bytes { |bytestr| ... } # iterate over f.dat 1 byte at a time.
 rio('f.dat').bytes[0...100]          # returns an array of the first 100 bytes of f.dat

Sets the Rio to chomp lines and returns the Rio

When called with a block, behaves as if chomp.each(&block) had been called

chomp causes lines returned by each, to_a, readlines, readline, gets, each_line etc. to be chomped before iterated over or assigned

 rio('f.txt').chomp.each { |line| ... } # Block is called with lines already chomped

 rio('f.txt').chomp { |line| ... } # same as above

 rio('f.txt').chomp.to_a # returns the lines of f.txt chomped

 rio('f.txt').chomp.lines(1..2).to_a # returns an array containg lines 1 and 2 of the file after being chomped

   This would have similar results to rio('f.txt').lines(1..2).to_a.map{ |line| line.chomp}

 rio('f.txt').lines(1..2).chomp.to_a # same as above

 rio('f.txt').chomp.readlines # returns the lines of f.txt chomped

 rio('f.txt').chomp.gets # returns the first line of 'f.txt' chomped

 rio('f.txt').chomp > an_array # copies the chomped lines of f.txt into an_array

 # fill an array with all the 'require' lines in all the .rb files (recursively) in adir
 # chomping each line

 an_array = []
 rio('adir').chomp.all.files("*.rb") { |file|
   an_array += file.lines[/^\s*require/]
 }

 or simply

 an_array = rio('adir').chomp.all.files("*.rb").lines[/^\s*require/]

Queries the Rio’s chomp-mode. See chomp.

Set a Rio’s closeoncopy mode

 ario.closeoncopy(&block) => ario

closeoncopy causes the Rio being written to to be closed when using a grande copy operator. While closeoneof causes all Rio’s to be closed when reading to the end of file, it does not affect Rios being written to. closeoncopy only affects the Rio being written to and only when a grande copy operator is used. closeoncopy is on by default, with one exception.

 dest = rio('destfile')
 dest < rio('srcfile')
 dest.closed?   #=> true

 dest = rio('destfile').nocloseoncopy
 dest < rio('srcfile')
 dest.closed?   #=> false
 dest.close     # must be explicitly closed

 dest = rio('destfile')
 dest.print(rio('srcfile').contents)
 dest.closed?   #=> false (IF::RubyIO#print is not a copy operator)
 dest.close

The Exception

When a block is passed directly to the rio constructor closeoncopy is turned off.

 rio('afile') { |file|
   file.closeoncopy? #=> false
   file < a_string
   file.closed?  #=> false
 }
 # The file is now closed. See IF::GrandeStream#rio for more informatioin

Why?

Some of my favorite Rio idioms are its copy one-liners

 rio('afile') < a_string # put a string into a file
 rio('afile') < an_array # put an array into a file
 rio('afile') < rio('anotherfile').lines(0..9) # copy the first 10 lines of anotherfile into afile
 rio('afile.gz').gzip < rio('anotherfile').lines(0..9) # same thing into a gzipped file

In each of these cases, ‘afile’ would remain open after the copy and furthermore since the destination Rio was not saved in a variable, There is no way to close file. Without closeoncopy Something like this would be required:

 ario = rio('afile')
 ario < something_else
 ario.close

Or this…

 ario = rio('afile') < something_else
 ario.close

Or this…

 (rio('afile') < something_else).close

One line, but ugly, and prone to error.

What I want is this:

 rio('afile') < something_else

Simple. I want to copy this to that, I point the arrow and it works.

In perl the rio’s destructor would be called, because there are no remaining references to the Rio However, it my understanding and experience that in Ruby the finalizer will not necessarily be called at this point.

Query a Rio’s closeoncopy mode

    ario.closeoncopy? => true or false

See closeoncopy

Set the Rio’s closeoneof mode.

 ario.closeoneof(&block) => ario

closeoneof causes a Rio to be closed automatically whenever the end of file is reached. This affects# all methods that read from a rio (readlines, #to_a, each gets etc.) Because closeoneof must be on for many of Rio’s most useful idioms, it is on by default. closeoneof can be turned off using nocloseoneof.

If a block is given behaves like ario.closeoneof.each(&block) had been called

Returns the Rio

 ario = rio('afile')
 lines = ario.readlines
 ario.closed?     #=> true

 ario = rio('afile').nocloseoneof
 lines = ario.readlines
 ario.closed?     #=> false
 ario.close       # must be explicitly closed

closeoneof is ignored by directory Rios, however, setting it on a directory Rio causes each file Rio returned while iterating to inherit the directory’s setting

 rio('adir').files do |file|
   file.closeoneof?    #=> true
 end

 rio('adir').files.nocloseoneof do |file|
   file.closeoneof?    #=> false
 end

 rio('adir').files.nocloseoneof['*.rb'] # array of .rb file Rios in adir with closeoneof off

 drio = rio('adir').files
 frio1 = drio.read
 frio1.closeoneof?    #=> true
 drio.nocloseoneof
 frio2 = drio.read
 frio2.closeoneof?    #=> false

Query a Rio’s closeoneof mode

 ario.closeoneof?    => true or false

See closeoneof and nocloseoneof

 ario = rio('afile')
 ario.closeoneof?  #=> true
 lines = ario.to_a
 ario.closed?     #=> true

 ario = rio('afile').nocloseoneof
 ario.closeoneof?  #=> false
 lines = ario.to_a
 ario.closed?     #=> false
 ario.close       # must be explicitly closed

Slurps the contents of the rio into a string.

 astring = rio('afile.txt').contents # slurp the entire contents of afile.txt into astring

Temporarily set the Rio to read lines, and call get

See also records, lines, each, []

Temporarily set the Rio to read records, and call get

See also records, lines, each, []

Temporarily set the Rio to read rows, and call get

See also rows, lines, each, []

Sets the Rio to gzip mode.

    ario.gzip    #=> ario

If applied to a Rio that is being read from Reads through a Zlib::GzipReader; If applied to a Rio that is being written to writes through a Zlib::GzipWriter.

Returns the Rio

If a block is given, acts like ario.gzip.each(&block)

 rio('afile') > rio('afile.gz').gzip # gzip a file
 rio('afile.gz').gzip < rio('afile') # same thing

 rio('afile.gz').gzip > rio('afile') # ungzip a file
 rio('afile') < rio('afile.gz').gzip # same thing

 rio('afile.gz').gzip.chomp { |line| ...} # process each chomped line of a gzipped file
 rio('afile.gz').gzip[0..9] # an array containing the first 10 lines of a gzipped file

Queries the Rio’s gzip-mode

 ario.gzip?     #=> true or false

See gzip

Calls lines(*args) but when used with the subscript operator returns the first element of the returned array instead of the array.

If afile contains ["line 0\n","line 1\n"]

 rio('afile').line[0]       #=> "line 0\n"
 rio('afile').line[1]       #=> "line 1\n"
 rio('afile').lines[0]      #=> ["line 0\n"]
 rio('afile').lines[1]      #=> ["line 1\n"]
 rio('afile').lines[0][0]   #=> "line 0\n"
 rio('afile').lines[1][0]   #=> "line 1\n"

Sets the rio to read lines and returns the Rio

If called with a block behaves as if lines(*args).each(&block) had been called

lines returns the Rio which called it. This might seem counter-intuitive at first. One might reasonably assume that

 rio('adir').lines(0..10)

would return lines. It does not. It configures the rio to return lines and returns the Rio. This enables chaining for further configuration so constructs like

 rio('afile').lines(0..10).skiplines(/::/)

are possible.

If args are provided they may be one or more of the following:

 rio('f.txt').lines(/^\s*#/) { |line| ... } # iterate over comment-only lines
 rio('f.txt').lines(/^\s*#/).each { |line| ... } # same as above

 rio('f.txt').lines(1,7..9) > rio('anotherfile.txt') # copy lines 1,7,8 and 9 to anotherfile.txt

 rio('f.txt').lines(1...3).to_a # return an array containing lines 1 and 2 of f.txt
 rio('f.txt').lines[1...3]      # same thing

Turns off both closeoneof and closeoncopy. Equivelent to:

 ario.nocloseoneof.nocloseoncopy

Returns the Rio

 ario.noautoclose(&block) => ario

If a block is given, acts as if

 ario.noautoclose.each(&block)

had been called.

See nocloseoneof and nocloseoncopy

Set a Rio’s closeoncopy mode to false

    ario.nocloseoncopy(&block) => ario

See closeoncopy

Set the Rio’s closeoneof mode to false

 ario.nocloseoneof(&block) => ario

See closeoneof

If a block is given behaves like

 ario.nocloseoneof.each(&block)

Returns the Rio

 ario = rio('afile')
 lines = ario.to_a
 ario.closed?     #=> true

 ario = rio('afile').nocloseoneof
 lines = ario.to_a
 ario.closed?     #=> false
 ario.close       # must be explicitly closed

Writes a single record to a Rio

Sets the implicit input mode to ‘r’.

The implicit input mode is the mode Rio will use for input when no mode is specified.

Returns the Rio

See the discussion for a.

Since ‘r’ is the implicit input mode used by default, this method is probably uneeded.

Sets the implicit input mode to ‘r+’.

The implicit input mode is the mode Rio will use for input when no mode is specified.

Returns the Rio

See the discussion for a.

See line.

Specifies which records will be iterated through by each or returned by getrec

If called with a block behaves as if records(*args).each(&block) had been called

Returns the Rio

If no args are provided, all records are selected. What constitutes a record is affected by lines,bytes, and extensions such as csv and yaml.

If args are provided they may be one or more of the following:

Any other argument type is compared with the record using its === method.

If the argument is a ::Proc it may be called with one, two or three paramaters.

1. the record
2. the recno (optional)
3. the rio (optional)

Note in the following examples that since lines is the default ario.records(*args) is effectively the same as ario.lines(*args).

 rio('afile').records(0) { |line| ... } # iterate over the first line of 'afile'
 rio('afile').records(0,5..7)) { |line| ... } # iterate over lines 0,5,6 and 7
 rio('afile').records(/Zippy/) { |line| ... } # iterate over all lines containing 'Zippy'

 rio('f.csv').puts!(["h0,h1","f0,f1"]) # Create f.csv

 rio('f.csv').csv.records[]    #==>[["h0", "h1"], ["f0", "f1"]]
 rio('f.csv').csv.lines[]      #==>["h0,h1\n", "f0,f1\n"]
 rio('f.csv').csv.records[0]   #==>[["h0", "h1"]]

See line.

Sets the Rio to read rows and specifies rows which should be iterated through by each or returned by getrec. rows is intended for use by extensions, where the concept of a row is reasonable. In the absensence of an extension behaves like records.

Sets the Rio to read lines and specifies lines which should not be iterated through by each or returned by getrec

If called with a block behaves as if skiplines(*args).each(&block) had been called

Returns the Rio

See also lines, records, skip

If no args are provided, no lines are rejected.

If args are provided they may be one or more of the following:

 rio('afile').skiplines(0) { |line| ... } # iterate over all but the first line of 'afile'
 rio('afile').skiplines(0,5..7)) { |line| ... } # don't iterate over lines 0,5,6 and 7
 rio('afile').skiplines(/Zippy/) { |line| ... } # skip all lines containing 'Zippy'
 rio('afile').chomp.skiplines(:empty?) { |line| ... } # skip empty lines

Specifies records which should not be iterated through by each or returned by getrec

If called with a block behaves as if skiprecords(*args).each(&block) had been called

Returns the Rio

See also records, skiplines, lines, skip

If no args are provided, no records are rejected. What constitutes a record is affected by lines,bytes, and extensions such as csv and yaml.

If args are provided they may be one or more of the following:

Note in the following examples that since lines is the default record type ario.skiprecords(*args) is effectively the same as ario.skiplines(*args).

 rio('afile').skiprecords(0) { |line| ... } # iterate over all but the first line of 'afile'
 rio('afile').skiprecords(0,5..7)) { |line| ... } # don't iterate over lines 0,5,6 and 7
 rio('afile').skiprecords(/Zippy/) { |line| ... } # skip all lines containing 'Zippy'
 rio('afile').chomp.skiplines(:empty?) { |line| ... } # skip empty lines

Sets the Rio to read rows and specifies lines which should not be iterated through by each or returned by getrec skiprows is intended for use by extensions, where the concept of a row is reasonable. In the absence of an extension behaves like skiprecords

This causes String#split(arg) to be called on every line before it is returned. An array of the split lines is returned when iterating

 rio('/etc/passwd').split(':').columns(0,2) { |ary|
   username,uid = ary
 }

 rio('/etc/passwd').split(':').columns(0,2).to_a #=> [[user1,uid1],[user2,uid2]]

See also split

Sets the Rio to strip lines and returns the Rio

When called with a block, behaves as if strip.each(&block) had been called

strip causes lines returned by each, to_a, readlines, readline, gets, each_line etc. to be stripped with String#strip before iterated over or assigned

 ans = rio(?-).print("A Prompt> ").strip.gets # prompt the user

See also chomp

Queries the Rio’s strip-mode. See strip.

Sets the implicit output mode to ‘w’.

The implicit output mode is the mode Rio will use for output when no mode is specified.

Returns the Rio

See the discussion for a.

Since ‘w’ is the implicit output mode used by default, this method is uneeded, but is provided for completeness..

Sets the implicit output mode to ‘w+’.

The implicit output mode is the mode Rio will use for output when no mode is specified.

Returns the Rio

 rio(?-,'cat').w!.puts!("Hello Kitty").readline #=> "Hello Kitty"

See the discussion for a.