On Mon, Jun 18, 2001 at 01:24:28AM +0000, Robin Gerard wrote:
> this script runs fine:
>
> #!/usr/local/bin/perl
>
> print "\n\n";
> %loginpsswd=("gerard","12345678","jaimie","78945612","andy","45632178");
for clarity, you should usually write hash-list expressions
with the => operator:
%loginpwd = (
gerard => "1234",
jaimie => "2468",
andy => "9999",
);
it's a little more clear that you've got key/values pairs, and
it provides some quoting to the left side of the "=>" so you
often don't need to quote them yourselves (but it never hurts to
do so -- and perl may gripe about barewords looking like perl
keywords)...
> print $loginpsswd{"gerard"};
> print "\n\n";
> print $loginpsswd{"jaimie"};
> print "\n\n";
> print $loginpsswd{"toto"};
> print "\n\n";
>
>
> but when instead of the six last lines I write:
>
> $i=0;
> while ($i<3)
> {
> print $loginpsswd{"$loginpasswd[2*$i]"};
> print "\n\n";
> }
> I get error ...
%something -> hash (record, indexed by field names)
@something -> array (numbered list of items)
$something -> scalar (single value: numeric, string)
$something{key} -> scalar value looked up from a hash/record
$something[ix] -> scala value looked up from an array
inside a "double-quoted" string, perl looks for patterns
that look like representations of variables, which can get
pretty complex -- but there's no math allowed within a
string (not without some @{[]} voodoo, anyway) so you
can't say
$x=3;
print "$x*2 nor 2*$x";
# -> generates "3*2 nor 2*3" not "6 nor 6"
you're looking for something like
foreach $user ( keys %loginstuff ) {
print "$user : $loginstuff{$user}\n"; # or
prnit $user," : ",$loginstuff{$user},"\n";
}
or
for ( ($k,$v) = each( %logingunk ) ) {
print "$k : $v\n";
}
try
perldoc -f each
perldoc -f keys
the camel book and the llama book are both wonderful resources
(for perl and for programming in general) at www.oreilly.com
--
DEBIAN NEWBIE TIP #10 from Will Trillich <[EMAIL PROTECTED]>
:
Looking to run a command or two at REGULAR INTERVALS? Try
"crontab -e" for starters (see "man cron" or "man crontab").
You might also investigate the "anacron" package.
Also see http://newbieDoc.sourceForge.net/ ...
