Prepent string a to string b if b does not start with a

Saved has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Prepent string a to string b if b does not start with a by choroba (Cardinal) on Mar 14, 2012 at 11:45 UTC
What do you mean by brute forcing this? `$pre = "PRE"; @S = qw/Q PREQ/; s/^(?!$pre)/$pre/ for @S; say for @S;` [download] or `$pre = "PRE"; @S = qw/Q PREQ/; for (@S) { $_ = $pre . $_ unless 0 == index $_, $pre; } say for @S;` [download]	[reply] [d/l] [select]
Re: Prepent string a to string b if b does not start with a by Corion (Patriarch) on Mar 14, 2012 at 11:36 UTC
How would you brute force this?	[reply]
Re^2: Prepent string a to string b if b does not start with a by Saved (Beadle) on Mar 14, 2012 at 11:46 UTC
`unless(grep(/^rte/, $ENV)) { $ENV = "rte" . $ENV; }` [download] This works, sorry to have distrubed anyone, and thanx	[reply] [d/l]
Re^3: Prepent string a to string b if b does not start with a by choroba (Cardinal) on Mar 14, 2012 at 11:48 UTC
Using grep for one-member list is strange. You can just use `if ($ENV !~ /^rte/)`	[reply] [d/l]
Re^4: Prepent string a to string b if b does not start with a by Saved (Beadle) on Mar 14, 2012 at 12:19 UTC
Re: Prepent string a to string b if b does not start with a by Anonymous Monk on Mar 14, 2012 at 15:43 UTC
Brute-force it, as you say, and move along. These aren't the 'droids you're looking for ...	[reply]