I can - very easily - write a Perl program to process every line of an incoming data file - indeed, that's much of where Perl originated as the "Practical Extraction and Reporting Language"
Here's a short example that processes every line of a file and reports each line that includes the string PHP as the second field of our line (which in the example happens to be a person's top skill):
open (FH,"../../requests.xyz") or die;
while ($line = <FH>) {
chop ($line);
@F = split (/\s+/,$line) ;
if ($F[1] eq "PHP") {
print $line;
print "\n";
}
}
Quick and easy, for sure ... but not as short (nor as quick and easy) as it might be for someone who's written a lot of Perl - this one line does the same:
perl -pae '$F[1] eq "PHP" or $_ = ""' ../../requests.xyz
Perhaps this is so short as to be obscure? If you're working in an environment when you often have to filter out a file quickly, then it's an excellent approach. If you're doing a lot of shell scripting, then a few Perl one-liners like this can save you an awful lot of more complex looking
awks and
seds.
As Damien Conway (one of the Perl team) said when I heard him lecture: "We're giving you a lot of very powerful tools. Be careful how you use them".
(written 2008-10-10 05:53:13)
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