James Gray
4/9/2007 12:04:00 PM
On Apr 9, 2007, at 6:52 AM, Joshua Muheim wrote:
> Hi all
>
> I'm looking for the coolest way to get the substring
>
> /Webwork/pgbookings
>
> out of
>
> /Users/Josh/Webwork/pgbookings
>
> The part /Users/Josh is saved in the variable my_var.
>
> In PHP I would do something like the following:
>
> substr(/Users/Josh/Webwork/pgbookings, strlen(my_var)) # =>
> /Webwork/pgbookings
>
> What's the fastest way to do this in Ruby? :-)
I'm not sure which way is faster, so let's ask Ruby to time some of
my ideas:
#!/usr/bin/env ruby -w
require "benchmark"
data = "/Users/Josh/Webwork/pgbookings"
prefix = "/Webwork/pgbookings"
TESTS = 1_000_000
Benchmark.bmbm do |results|
results.report("[i..-i]:") { TESTS.times { data
[prefix.length..-1] } }
results.report("[i, l]:") { TESTS.times { data[prefix.length,
data.length] } }
results.report("sub():") { TESTS.times { data.sub(/\A#{prefix}/,
"") } }
results.report("[re, c]:") { TESTS.times { data[/\A#{prefix}(.+)/,
1] } }
end
# >> Rehearsal --------------------------------------------
# >> [i..-i]: 2.500000 0.000000 2.500000 ( 2.511868)
# >> [i, l]: 0.630000 0.000000 0.630000 ( 0.634460)
# >> sub(): 6.800000 0.020000 6.820000 ( 6.850561)
# >> [re, c]: 7.180000 0.010000 7.190000 ( 7.204910)
# >> ---------------------------------- total: 17.140000sec
# >>
# >> user system total real
# >> [i..-i]: 2.500000 0.000000 2.500000 ( 2.500795)
# >> [i, l]: 0.630000 0.010000 0.640000 ( 0.633458)
# >> sub(): 6.840000 0.000000 6.840000 ( 6.853133)
# >> [re, c]: 7.110000 0.010000 7.120000 ( 7.130398)
__END__
Hope that helps.
James Edward Gray II