Pattern Matching - Using a variable 2

[glwong]

I am storing a line of charcaters in a variable
($line) and am trying to search a buffer
for the pattern. I have two issues,

1)
The buffer contains $line but it is preceded
by extra characters (for example 123456$line)

2)
Is there a way to search the buffer using
the variable ($line)? In essence I want to


$buffer =~ /*($variable)/;

but I know that is the wrong syntax, is there
a way to achieve my goal?

Thanks,
Greg

 

[hmerrill]

How about

if ($buffer =~ /$variable/) {
### found $variable in $buffer - do something
}
else {
### did *NOT* find $variable in $buffer - do something else
}

Does this answer your question? To find more info on Perl regular expressions, do "perldoc perl" and look for regular expression topics - Perl 5.6.1 has these topics:

perlrequick Perl regular expressions quick start
perlretut Perl regular expressions tutorial
perlre Perl regular expressions, the rest of the story

HTH.
Hardy Merrill
Mission Critical Linux, Inc.

http://www.missioncriticallinux.com

 

[tsdragon]

If you don't care where in $buffer the variable $line occurs, just that it occurs somewhere, try this one:

$buffer =~ /$line/;

If you know that the value of $line is not going to change, you can gain a little efficiency by adding o after the final /

If you want to make sure that $line occurs only at the end of $buffer, this will do it:

$buffer =~ /$line$/;

Note that the trick with using variables is that they're not the last thing in the regex (otherwise they look like an end-of-line test), and the variable actually exists. Tracy Dryden
tracy@bydisn.com

http://www.bydisn.com

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.

 

[oinky]

I've found that there are problems in matching strings in variables if the string you are trying to match contain slashes. Say if you are trying to match " C:\blah\blah1 " and you store this into a variable. Something like:

$variable = 'c:/blah/blah1';
$buffer =~ m/$variable/;

or

$variable = "c:\\blah\\blah1";
$buffer =~ m/$variable/;


I've tried using "/" slash also "\\" but still does not seem to work properly. I wonder if any1 have this problem as well.

 

[greadey]

Not sure why the second one won't work, but in the first case why don't you slap a different pair of regexp delimiters around $variable;

summat like;

$variable = "c:/blah/blah";
$buffer =~ m|$variable|;

 

[oinky]

shoot good idea! why didnt i think of that heh 8)