The code at bottom works fine for converting all alpha characters in a text file to upper (or lower) case. But having the two "$munged = " lines inside the "for(@in)" loop looks like ineficient if handling large files.
I tried these two tweaks to move that logic outside the for(@in) loop. The first doesn't work because (correct me if I'm wrong) $_ is empty when $munged is declared. The second fails with this compilation error: syntax error at uclc.pl line (push @munged, $munged();), near "$munged(" and I'm not clear just what's happening there.
# tweak one
my @munged;
my $munged = lc() if ($uclc eq 'lc');
$munged = uc() if ($uclc eq 'uc');
for(@in) {
push @munged, $munged;
}
# tweak two
my @munged;
my $munged = lc if ($uclc eq 'lc');
$munged = uc if ($uclc eq 'uc');
for(@in) {
push @munged, $munged();
}
So my questions for the wise bretheren and sisteren are:
- should I be concerned about potential ineficiency of this code for large input files?
- if so, how might it be improved?
cheers,
Don
striving toward Perl Adept
(it's pronounced "why-bick")
#!/usr/bin/perl -w
use strict;
my $uclc = shift or Usage();
my $infile = shift or Usage();
my $outfile = shift or Usage();
Usage() unless ($uclc eq 'lc' or 'uc');
open (IN, "< $infile") or die "Error opening $infile for read: $!";
my @in = <IN>;
close IN or die "Error closing $infile after read: $!";
my @munged;
for(@in) {
my $munged = lc() if ($uclc eq 'lc');
$munged = uc() if ($uclc eq 'uc');
push @munged, $munged;
}
open (OUT, "> $outfile") or die "Error opening $outfile for write: $!"
+;
print OUT for(@munged);
close OUT or die "Error closing $outfile after write: $
+!";
######################################################################
+####
sub Usage {
die "\n Usage: uclc.pl (lc|uc) infile outfile\n";
}
######################################################################
+####
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