Feature #8515

don't allow irb to dump output for forever and ever

Added by Josh Sharpe over 2 years ago. Updated over 1 year ago.



You've done this before, I know you have. You were screwing around in IRB and you ran something stupid and IRB just started dumping output. LOTS of output. Output that would scroll by for an hour if you don't go kill it. Output going by so fast that it's useless. So much output that your lappy laptop starts burning your knees. (That much output!)

Then, to compound problems, Crtl-C doesn't work here. Maybe you're in some weird context, or on a low-mem server and everything is just... What, Bam, UNRESPONSIVE.

Ugh, the troubles! Now you gotta gotta bust out the 'kill -9' (if you can even get another terminal open) and lose any progress you may have been working on.... OH MAN!

Wouldn't it be nice if IRB limited its output, much the way psql/less do? That is, at some point if enough output has scrolled by, Stop, and let me have the option to continue or not.

That'd be cool.



#1 Updated by Anonymous over 2 years ago

On 06/11/2013 09:41 AM, crankharder (Josh Sharpe) wrote:

Feature #8515: don't allow irb to dump output for forever and ever

Agreed, it would be nice to have LESS(1) functionality in irb.

Have you tried the pry gem? It does behave like less (including regex

If you want to use irb, there is this snippet for your .irbrc (though it
seems incompatible with wirble), which abbreviates long output:

# credit to Stian Haklev
class IRB::Context
attr_accessor :max_output_size

alias initialize_before_max_output_size initialize
def initialize(*args)
  @max_output_size = IRB.conf[:MAX_OUTPUT_SIZE] || 500


class IRB::Irb
def output_value
text =
if @context.inspect?
sprintf @context.return_format, @context.last_value.inspect
sprintf @context.return_format, @context.last_value
max = @context.max_output_size
if text.size < max
puts text
puts text[0..max-1] + "..." + text[-2..-1]

#2 Updated by Nobuyoshi Nakada over 2 years ago

You can run irb with --noecho option, or set `IRB.conf[:ECHO] = false' in .irbrc.

#3 Updated by Hiroshi SHIBATA over 1 year ago

  • Status changed from Open to Feedback

#4 Updated by Andrew Vit over 1 year ago

pry's pager is very cool, but it seems that it needs to build the whole string output before it gets echoed back to the screen using less. Maybe something better could be done for that within irb by "streaming" the output buffer?

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