John W. Krahn wrote:
Prabu Ayyappan wrote:
From: Manoj <[EMAIL PROTECTED]>
Have a CSV file with the first column as unique which I am taking as
hash
key and rest of the line as hash value. I am opening the file and
putting to
hash after reading each line. There are two questions from me.
1) How to find the performance and time taken by Perl script?
2) Is there any optimal method for reading a CSV file and put
to hash
table.
Note: This is only a part of script doing and I am supposed to do
this with
out using any default modules.
1) How to find the performance and time taken by Perl script?
For benchmarking the perl scripts you can use the Benchmark module.
http://search.cpan.org/~rgarcia/perl-5.10.0/lib/Benchmark.pm
Benchmark.pm *should* be installed as a standard module when Perl was
installed. Check the "Standard Modules" section of perlmodlib.pod
perldoc perlmodlib
perldoc Benchmark
2) Is there any optimal method for reading a CSV file and put to
hash table.
May have better approaches however this read CSV into Hash
use Data::Dumper;
open(INFILE, "<", "sample.csv") or die $!;
my %hsh;
%hsh = ( %hsh, (split(/,/, $_))[1,2] ) while ( <INFILE> );
That is a *very* inefficient way to populate a hash as you are copying
the entire hash for every record in the file. Better to add the keys
and values individually:
my %hsh;
while ( <INFILE> ) {
chomp;
my ( $key, $value ) = split /,/;
# Oops :-)
$hsh{ $key } = $value;
}
print Dumper \%hsh;
John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall
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