Re: grep --ignore-case efficiency

[Paulo Nogueira]

 Thank you Arnold and Johannes for your comments.
 For convenience I'll do a mixed reply below.

> The simple solution was to do
>
>        export LC_ALL=C
>
> and then run grep, which would give you a big speedup.

 Tried it and, indeed, this gives a big speedup!
 Comparable times on an old version of grep (2.5.1),
 but on a recent installation of Fedora (grep 2.14)
 it does not work just as well because it's still about
 10x slower (in my test case, with a simple text string).
 Ten times is still better than ninety times, although
 it's not expected after seing the result of grep 2.5


> Have a look at
> http://en.opensuse.org/SDB:Plain_Text_versus_Locale
> in particular the section
> "Processing UTF-8 is slower than ISO-8859 and ASCII"
> and replace the "wc" tool therein with "grep".

 Tried also

 export LC_ALL=POSIX ; export LANG=POSIX

 as explained in the web page you cited, but still no
 improvements on Fedora 18. Maybe there is some other
 factor to take into account.

 Thanks,
   Paulo