On Tue, 18 Mar 2003, Scott R. Godin wrote:
> John W. Krahn wrote:
>
> > David Gilden wrote:
> >>
> >> OK, one problem is solved, which was the path to the data file.
> >> I know there is a simple way to read in a file like the following:
> >>
> >> apple,2
> >> banana,4
> >> kiwi,1
> >>
> >> and produce a HASH. The code below works I get the feeling there is a
> >> more compact way to accomplish this.
> >
> > Yes, there is. :-)
> >
> > my %hash = do { local $/; <FH> =~ /[^\n,]+/g };
>
> Holy Handgrenades, Batman!
>
> but where's the implicit split of key and value there? forgive me for
> asking, but I just don't see it. is there some magic going on here?
Step 1) local $/
$/ (input record separator) defines what constitutes a line in perl. By
default it is set "\n". The statement "local $/" undefines $/ within
this do block i.e. you are now operating in slurp mode.
perldoc perlvar # Search for INPUT_RECORD_SEPARATOR
Step 2) <FH> =~ /[^\n,]+/g
Remember you are in slurp mode, so a <FH> would return the string
"apple,2\nbanana,4\nkiwi,1\n". The regex matches anything that is not a
',' or "\n" and thus performing the split for you.
The do block returns the value of the last statement, in this case the
result of the regex in a list context due to the my %hash = do {...}
The returned list is ('apple', 2, ....) which gets assigned to %hash and everybody is
happy :-)
hth
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
