jeah has asked for the wisdom of the Perl Monks concerning the following question:
Hi, I hope my questions aren't trivial, I can't figure out why replacing the default $_ with an arbitrary variable gives different results, my questions follow, hope you can help, thanks :)
I'd also like to know why if I specify even-numbered elements, nothing returns, eg. if I type
print $fields[0], "\r";on line 12 in my script, I get nothing. I've found that any even-numbered element specified on line 12 gives me nothing, it's odd, I thought the 0th element would be 'Baw', the 1st element would be 'Vao' and so on. The pipe is discarded by perl, so I don't understand why the even-numbered elements are 'skipped', so to print 'Baw', I type
print $fields[1], "\r"and to print 'Vao', I type
print $fields[3], "\r"1. If I use $in on Lines 6 - 8 and print any elements, the entire lines of the file are returned without being processed (with pipes included). I thought I could substitute $_ with any variable. Why won't it work here?
2. If I use $_ on these lines instead, then I get good results (eg. I get the element specified on Line 12.
3. If I UnComment Lines 9 - 11, a '1' is returned for each record/line between the last 2 elements from the file. Why is that?
1 #!/usr/bin/perl -w 2 use strict; 3 4 open my $datfh, '<', 'C:\begperl\my scripts\cdata.txt' or die "Could +n't open file: $!\n"; 5 6 foreach my $_ (<$datfh>) { 7 my @fields = (map { s/^\s+//; s/\s+$//, $_ } # eliminates irr +elevant spaces 8 split /\|/, $_); 9 # for my $i (0 .. $#fields) { 10 # print $fields[$i], "\n" unless $fields[$i] =~ /\r|\n/; 11 # } 12 print $fields[1], "\r"; 13 } 14 close $datfh;
My File's data (for testing):
Baw|Vao|111 Noa St||NewYork|NY|10012|2123456789|123456789
Vca|Wxr|384 Mkl Ln|Xillo|Crrnt Stt|CT|05506|1015567781|1015567782
Uaa|Kvbr|805 Test Rd|Zero|This St|MN|17205|3018757203|3012986736
Caa|Lvbr|905 Test Rd|Bero|That St|MD|12705|3028887203|3028886736
Eaa|Pvbr|311 Zest Rd|Tero|My St|MI|12505|3018757203|3012986736
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Re: variable mystery
by oko1 (Deacon) on Nov 29, 2008 at 00:40 UTC | |
by ikegami (Patriarch) on Nov 29, 2008 at 02:59 UTC | |
by jeah (Novice) on Nov 29, 2008 at 05:27 UTC | |
by Anonymous Monk on Nov 29, 2008 at 05:37 UTC | |
by jeah (Novice) on Nov 29, 2008 at 07:21 UTC | |
by parv (Parson) on Nov 29, 2008 at 07:59 UTC | |
by ikegami (Patriarch) on Nov 29, 2008 at 12:44 UTC | |
by jeah (Novice) on Nov 30, 2008 at 02:29 UTC | |
by CountZero (Bishop) on Nov 29, 2008 at 08:10 UTC | |
by pobocks (Chaplain) on Nov 29, 2008 at 10:37 UTC | |
by ikegami (Patriarch) on Nov 29, 2008 at 12:50 UTC | |
by mandarin (Hermit) on Nov 29, 2008 at 12:52 UTC | |
Re: variable mystery
by parv (Parson) on Nov 29, 2008 at 08:03 UTC |