On Tuesday 08 February 2005 18:57, Scott R. Godin wrote:
> This is my first time attempting to use Term::ReadLine to get input from
> the commandline while a script is running. I grok the basics of it, but
> am stumbling over the implementation of it. Let me illustrate:
>
> READLINE:
> {
> # closure, so I don't have to either
> # - call Term::ReadLine->new() every time thru the sub, or
> # - pass the object to the sub every time thru
> # this way it gets called _once_, period, and I don't have to think
> # about it later
> my $term = Term::ReadLine->new();
>
> sub get_input ($;$) {
[..]
> }
> }
>
[..]
>
> while ( get_input "What is the full path to the directory containing\
> your website .html files", $default->() ) {
> print && next unless $_; #DEBUG
> print "nonexistent: $_" && next unless -d ;
> print "not readable: $_", next unless -r;
> die "directory not writable by this process. check permissions on:
> $_" unless -w;
> $input{htdocs} = $_;
> }
>
[..]
>
> My brain seems frozen today. How do I ensure that the input loop will
> continue if the value is not defined, and test the values if they are ?
> I'm guessing a continue block but I can't seem to wrap my brain around
> the problem today. I should KNOW this, dammit! It's killing me that I
> can't figure it out, and I'm sure it'll be obvious in retrospect.
>
> should I even be using 'while' here?
I would say 'no' to this one ;-)
Why do you need a loop here? The way you've written your get_input() method,
you'll always get a return value - either the one from the user, or a default
value. Even if you implement a query without return value, your directory
checks will catch it because "-d undef" returns 0, so the user would get the
message "nonexistent: " if he enters no value for a question without default
value, which is more or less correc.t
Maybe I didn't get the point, but I would probably write it like this:
##################################################################
#!/usr/bin/perl -w
use strict;
use Term::ReadLine;
my(%input, $default);
$default = sub { .. };
# declaring the console object globally
my $term;
sub get_input ($;$) {
my($descr, $default) = @_;
print "No description specified for input"
unless $descr;
$default ||= '';
my $result = $term->readline("$descr [$default]: ") || $default;
return $result;
}
### main
$term = Term::ReadLine->new();
$_ = get_input "What is the full path to the directory containing your \
website .html files", $default->();
die "nonexistent: $_" unless -d;
die "not readable: $_" unless -r;
die "directory not writable by this process. check permissions on: $_" unless
-w;
print "ok - got $_\n";
$input{htdocs} = $_;
##################################################################
If you want to process a batch query, you can always build a while loop around
it like this:
my @queries = (
{'name' => 'htdocs',
'description' => 'Full path to your htdocs',
'default' => $default
},
{'name' => 'home',
'description' => 'Your home directory, if you please:',
'default' => sub { return $ENV{HOME}; }
}
);
foreach my $query_ref (@queries) {
$_ = get_input(
$query_ref -> {'description'},
$query_ref -> {'default'} -> ()
);
die "nonexistent: $_" unless -d;
die "not readable: $_" unless -r;
die "directory not writable by this process. check permissions on: $_"
unless -w;
print "ok - got $_ for $query_ref->{'name'}\n";
$input{$query_ref->{'name'}} = $_;
}
HTH,
Philipp
>
> --
> Scott R. Godin
> Laughing Dragon Services
> www.webdragon.net
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