How to extract the number which is present after AAA?
12345 AAA 67890
I need 67890 to be extracted.
Thanks.
LINUX CLASSES - PERL PROGRAMMING
One mystery remains: What's this (/^#/) stuff all about? Remember the grep command, and the discussion of regular expressions? If
you think about it, the little Perl program in the previous example acts a lot like grep ,
since it sifts through each line and prints it if a pattern is matched.
In Perl, the forward slashes indicate that a pattern match is to be performed. The regular
expression inside the slashes defines the search pattern, and $_ is the variable that the
search is performed on. In our case, the ^# inside the slashes means to match only lines
that begin with the pound sign.
How Does Perl Pattern Matching Work?
So if we make the previous example a bit more generic, allowing it to get the search pattern and file name from the command line, it will behave almost exactly like the grep utility:
open MYFILE, $ARGV[1] or die "Can't open $ARGV[1]: $! \n";
while (<MYFILE>) {
if (/$ARGV[0]/) { print "MATCH: $_"; }
}
Learn More about Perl
We've barely scratched the surface of what you can do with the Perl language. Try the man perl command to get more information on Perl, read Programming Perl by Larry Wall (O'Reilly & Associates), the inventor of the Perl language, or visit the Perl Institute Web site at http://www.perl.org.
Previous Lesson: Perl and Files
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Comments - most recent first
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I welcome your comments. However... I am puzzled by many people
who say "Please send me the Linux tutorial." This website *is* your Linux Tutorial! Read everything here, learn
all you can, ask questions if you like. But don't ask me to send what you already have. :-)
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