Hi Nora! Welcome to Perl.
On Wednesday 24 Feb 2010 11:00:46 HACKER Nora wrote: > Hi, > > I want to apply a certain substition to a string, whereas the whole > substitution is defined in a variable in another script. Unfortunately, > it doesn't work as wanted :-( Looks like this: > > sub.conf: > $sub='s/db$//g'; Please add "use strict;" and "use warnings;" to your code. You cannot put a s/../.../ expression directly in a variable and except it to work on the right-hand-side (RHS) of a =~. It doesn't work that way. > > script.pl: > do sub.conf; Why are you using "do" instead of "use" or "require"? See http://perl-begin.org/ for more information and recommended books and tutorials. And again you should add strict and warnings. > print "Please enter string: "; # e.g. mydb > $input=<STDIN>; Normally <ARGV> - shortened to <> is preferable over <STDIN>; > print "$sub\n"; # gives the exact string as defined in sub.conf > (without apostrophes) > $input=~$sub; > print "$input\n"; # in this example should be "my" > > Can anybody please tell me my mistake? You can do one of the following: 1. Put the left-hand-part of the s/// in a qr// variable: (Untested) <<< my $exp = qr{hello$}; my $string = "Time to say hello"; $string =~ s{$exp}{goodbye}; >>> 2. You can also try using the stringified eval "" (which could be error prone and generally not recommended. 3. You can try constructing a closure: (Untested) <<< my $op = sub { my $s = shift; $s =~ s{hello$}{goodbye}; return $s; }; . . . print $op->("Time to say hello"), "\n"; >>> Regards, Shlomi Fish -- ----------------------------------------------------------------- Shlomi Fish http://www.shlomifish.org/ "Star Trek: We, the Living Dead" - http://shlom.in/st-wtld Deletionists delete Wikipedia articles that they consider lame. Chuck Norris deletes deletionists whom he considers lame. Please reply to list if it's a mailing list post - http://shlom.in/reply . -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
