No matching

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

Hi there,
I have following substring at the beginning of an output

my $prefixSysDescr = "system\.sysDescr\.0 : DISPLAY STRING- (ascii):";

I want to remove it. As it is only one substring to be removed, I do a kind of case structure like this:

for ( $sysDescr ) {
   /^$prefixSysDescr/ && do {
     s/^$prefixSysDescr//;
    last;
    };
} # end of case
[download]

Neither /../ && do { ..}; nor substitue s/..//; matches as expected. Any idea? thx 4 help

Comment on No matching Select or Download Code

Replies are listed 'Best First'.
Re: No matching by shmem (Chancellor) on Sep 03, 2009 at 08:16 UTC
The parens spoil your match. See quotemeta. `my $prefixSysDescr = quotemeta 'system.sysDescr.0 : DISPLAY STRING- +(ascii):'; my $sysDescr = 'system.sysDescr.0 : DISPLAY STRING- (ascii): fub +ar'; $sysDescr =~ s/$prefixSysDescr//; print $sysDescr,$/; __END__ fubar` [download] Alternatively, do `$sysDescr =~ s/\Q$prefixSysDescr\E//;` [download]	[reply] [d/l] [select]
Re^2: No matching by o_chfa (Acolyte) on Sep 03, 2009 at 08:58 UTC
This is a very valuable hint. I take care for this in future. \Q with \E didn't worked.	[reply]
Re^3: No matching by Anonymous Monk on Sep 03, 2009 at 09:10 UTC
\Q\E is quotemeta, you must have done it wrong	[reply]
Re^4: No matching by o_chfa (Acolyte) on Sep 03, 2009 at 09:24 UTC
Re^5: No matching by Anonymous Monk on Sep 03, 2009 at 11:15 UTC
Some notes below your chosen depth have not been shown here
Re: No matching by tmharish (Friar) on Sep 03, 2009 at 08:21 UTC
As already pointed out it will help if you gave us the input. In general however I find it very helpful if I start building regular expressions in parts. So instead of writing it all out maybe you can start with: `my $prefixSysDescr = "system.sysDescr"; if( $input_var =~ /$prefixSysDescr/ ) { print "Match!\n"; }` [download] Once you are sure that that part works you can then start adding more of what you want matched. That way you get a clearer idea of where your RegEx is failing - Which I believe is the problem here.	[reply] [d/l]
Re^2: No matching by o_chfa (Acolyte) on Sep 03, 2009 at 09:11 UTC
Your advice starting with smaller parts of the string failed too. So I assume your thinking of RegEx failing was right. By accident I looked at the 1st line of my script and discoverd a fishy looking shebang (the exclamation mark/point was missing and a strange path). I discovered the path to perl with `which perl` After fixing the shebang with exclamation mark/point and the discovered path and implementing "quotemeta" I restarted the script successfuly. Thx for the ideas	[reply] [d/l]
Re: No matching by grizzley (Chaplain) on Sep 03, 2009 at 08:03 UTC
You don't have to add backslash before dot character. I bet you must add backslash before special characters - parens in `$prefixSysDescr`. Can you add input string example to your post?	[reply] [d/l]