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perl regexp matching

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# 1  
Old 04-14-2010
perl regexp matching
Hello,

I cannot see what's wrong in my code.
When I run code below, it just print an empty string.

PHP Code:
my $test = "SWER~~ERTGSDFGTHAS_RTAWGA_DFAS.x4-234253454.in";
if ($test = ~ m/\~{1,2}[A-Z].*[xX]4/) {
   print "$1\n";
}
else {
   print "No match...\n";
} 
Anyone know what I'm doing wrong?

Thanks in advance!
# 2  
Old 04-14-2010
Because you ain't got a matching group () anywhere that could put something into $1.
# 3  
Old 04-14-2010
Quote:
Originally Posted by pludi
Because you ain't got a matching group () anywhere that could put something into $1.
Okay, but should it not at least run the else statment then?

I thought my regular expression would match "~~ERTGSDFGTHAS_RTAWGA_DFAS.x4" ?

Perhaps anyone can show me how I match above string?
# 4  
Old 04-14-2010
Yes, it does match. Which is why it's not moving into the else branch. But without a matching group it doesn't know what to put into $1, so it just prints an empty line.

Compare your code with this:
Code:
my $test = "SWER~~ERTGSDFGTHAS_RTAWGA_DFAS.x4-234253454.in";
if ($test = ~ m/(~{1,2}[A-Z].*[xX]4)/) {
   print "$1\n";
}
else {
   print "No match...\n";
}

# 5  
Old 04-15-2010
Quote:
Originally Posted by pludi
Yes, it does match. Which is why it's not moving into the else branch. But without a matching group it doesn't know what to put into $1, so it just prints an empty line.

Compare your code with this:
Code:
my $test = "SWER~~ERTGSDFGTHAS_RTAWGA_DFAS.x4-234253454.in";
if ($test = ~ m/(~{1,2}[A-Z].*[xX]4)/) {
   print "$1\n";
}
else {
   print "No match...\n";
}

Ah okay, now I understand Smilie

Thanks a lot.
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