Print to log file without newline - Ruby on Rails

Question

I have a logger to print to a file:

logger = Logger.new Rails.root.join 'log/my.log'

How can I print several dots in one line in different logger calls?

i.e., if I do

some_array.each do |el|
  logger.info '.'
  el.some_method
end

These dots will be printed in different lines.

Answer 1

The << method lets you write messages without any formatting the log file.

For example:

require 'logger'

log = Logger.new "test.log"
log.info "Start"
5.times { log << "." }
log << "\n"
log.info "End"

Produces:

I, [2014-03-10T15:11:04.320495 #3410]  INFO -- : Start
.....
I, [2014-03-10T15:11:42.157131 #3410]  INFO -- : End

Unfortunately, this doesn't let you write to the same line as previous calls to log.info

Answer 2

You can use Logger#<<(msg)

Dump given message to the log device without any formatting. If no log device exists, return nil.

some_array.each do |el|
  logger << '.'
  el.some_method
end