Re: Stop variable expansion

If you want to search for a string, not a regex, use index.

my $Name = '[A';
my $SearchInHere = 'FredJimBert';
if (-1 != index $SearchInHere, $Name)
{
  DoSomething();
}
[download]

> so I can't escape it.

Of course you can. See quotemeta. But I still think using the above solution is better.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

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Re^2: Stop variable expansion by SteveDC (Initiate) on Mar 19, 2021 at 03:20 UTC
Excellent. Index did the trick. I think indexing is the better solution than character replacement since I don't have to think about all possible characters that could cause issue, and it just does the comparison character by character regardless, which is really what I want in this case. Expanding the regular expression is also extremely useful and I use it a lot in other applications but thought I had to explicitly enable it (with eval) rather than explicitly disable it somehow. Anyhow. Thanks for the solution :) BR, Steve	[reply]
Re^3: Stop variable expansion by AnomalousMonk (Archbishop) on Mar 19, 2021 at 06:05 UTC
I think indexing is the better solution than character replacement ... index seems a very good match to your use-case. ... I don't have to think about all possible characters that could cause issue ... That's exactly what quotemeta (and its `\Q...\E` avatar) does for you: escape all characters that could possibly cause an issue. Expanding the regular expression is also extremely useful and I use it a lot in other applications but thought I had to explicitly enable it (with eval) rather than explicitly disable it somehow. I don't understand what this means. Are we still talking about meta-quotation? Could you give an example of what you're doing with eval? (Please see Short, Self-Contained, Correct Example.) Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^2: Stop variable expansion by SteveDC (Initiate) on Mar 19, 2021 at 03:24 UTC
OK, so I didn't know how to replace the "rogue" characters with escaped versions, and looking at the solution there is no way I would have been able to work that one out !!! :) Indexing I think is the right solution and better matches the intent, i.e. find 'this' in 'that'. Thanks for taking the time to reply and help. Very much appreciated. BR, Steve	[reply]
Re^3: Stop variable expansion by GrandFather (Saint) on Mar 19, 2021 at 03:38 UTC
looking at the solution there is no way I would have been able to work that one out Of course there was a way - RTFM: read the fine manual. In fact both answers gave you the reference you needed: quotemeta. One of Perl's good points is comprehensive documentation. Sometimes it takes some digging, and it's harder if you don't know what you are looking for, but it's almost always there. For future reference you can of course quote problematic strings (as already noted in earlier answers): `use strict; use warnings; my $Name = '[A'; my $SearchInHere = "FredJimBert[A"; print "Matched quoted\n" if $SearchInHere =~/\Q$Name\E/; print "Matched raw\n" if $SearchInHere =~/$Name/;` [download] Prints: `Unmatched [ in regex; marked by <-- HERE in m/[ <-- HERE A/ at noname. +pl line 8. Matched quoted` [download] Output order is backwards in time, but that's pretty normal for errors and warnings. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply] [d/l] [select]