Ruby Outputting to the Same Line as the Previous Output

Ruby outputting to the same line as the previous output

Yes, use print var instead; puts automatically appends a new line, print doesn't.

Ruby multiple print on the same line

could use \r..

while(true) do
  print "\\\r"
  print "|\r"
  print "/\r"
end

Will print the char and then move the cursor back and print over it, making a little spinner like thing. Else you can look at something like curses.... (https://github.com/rkumar/rbcurse for a ruby wrapper)

Writing over previously output lines in the command prompt with ruby

Use \r to move the cursor to the beginning of the line. And you should not be using puts as it adds \n, use print instead. Like this:

print "11MB 294K/s"
print "\r"
print "12MB 307K/s"

One thing to keep in mind though: \r doesn't delete anything, it just moves the cursor back, so you would need to pad the output with spaces to overwrite the previous output (in case it was longer).

By default when \n is printed to the standard output the buffer is flushed. Now you might need to use STDOUT.flush after print to make sure the text get printed right away.

output a line to a line before in ruby

f.puts "The result is: #{my_array.flatten.join(" ")}"

Ruby doesn't read carriage return (\r) in output?

puts will always print a new line at the end, so it's doing your carriage return but then a new line after that. Use print instead.

90.times { |i| print "#{i} matt lao \r" }

To see it's actually doing the right thing, you can stick in a sleep:

90.times { |i| print "#{i} matt lao \r"; sleep 0.01 }

Elegantly put strings in same line

I suggest constructing an array and using the join method.

def printStrings do *strings
    strings.join(', ')
end

printStrings 'apple', 'banana', 'orange' #'apple, banana, orange'

Alternatively, you can utilize a special variable, called the output field separator, which you can access as $,. (Its default value is nil)

$, = ', '
print 'apple', 'banana', 'orange' #'apple, banana, orange'
$, = nil

This method is outlined in the docs for print

How could I display a text on the same line?

The method gets without any option receives the input including the terminating end of line. If you simply interpolate that as a part of a string, that end of line will be printed as a line break.

To avoid line break, pass the parameter chomp with value true to gets:

$name = STDIN.gets(chomp: true)

In the old school way, apply chomp after gets like:

$name = STDIN.gets.chomp

chomp removes white space characters from the end of the string, thus it avoids the line break.

Other things wrong about your code are:

• You missed to capitalize the sentence whats your name?.
• You missed an apostrophe in whats.
• You should avoid using a global variable like $name. Try using another type of variable.
• You missed a period at the end of the sentence Oh #$name, nice to meet you.

How to overwrite a printed line in the shell with Ruby?

You can use the \r escape sequence at the end of the line (the next line will overwrite this line). Following your example:

require 'time'

loop do
  time = Time.now.to_s + "\r"
  print time
  $stdout.flush
  sleep 1
end

Use repeat of format for many variables on the same line

You could write the following.

def print_my_string(tn, ln, *ints)
  fmt = "%-10s" + ("|#{"%2s" % ln}%3d" * ints.size) + "|"
  puts fmt % [tn, *ints]
end

Then, for example,

print_my_string("hello", "ho", 2, 77, 453, 61, 999)

displays

hello     |ho  2|ho 77|ho453|ho 61|ho999|

after having computed

fmt = "%-10s" + ("|#{"%2s" % ln}%3d" * ints.size) + "|"
  #=> %-10s|ho%3d|ho%3d|ho%3d|ho%3d|ho%3d|"

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