On Oct 29, 11:09 am, [EMAIL PROTECTED] (John W . Krahn) wrote:
> On Monday 29 October 2007 06:42, Mike Tran wrote:
>
> > Hey all,
>
> Hello,
>
> > I'm new with Perl and need help with this simple script. I'm still
> > playing around with the script below to get a feel for Perl. My
> > script below is incomplete and I'm doing an array within an array
> > which is incorrect. Please help.
>
> You are not using arrays you are using hashes.
>
>
>
> > Here's what I want to do; I have to flat files (pipe delimited,
> > export from a database) that I want to parse through and assign
> > variables for each column. Basically, I want to parse through
> > exclude_bases.txt and do: if base_no in exclude_bases.txt equals to
> > base_no in base.txt then search in the "description" field of
> > base.txt for the string listed in the "keyword" field in
> > exclude_bases.tx and replace with "new_keyword" in exclude_bases.txt
> > and write the out put into a new file called "new_bases.txt".
>
> > Any suggestions on how I could accomplish the above task is greatly
> > appreciated. Thanks all.
>
> > Flat Files:
>
> > base.txt:
> > base_no|name|description
> > 10000|test|test desc
> > 10001|test2|test desc 2
> > 10002|test3|test desc 3
>
> > exclude_bases.txt:
> > base_no|keyword|new_keyword|
> > 10000|test desc|testdesc|0
> > 10001|test desc 2|testdesc2|0
> > 10002|test desc 3|testdesc3|1
>
[snip]
> It looks like you may want something like this:
>
> #!/usr/bin/perl
> use strict;
> use warnings;
>
> my $exclude_bases = 'exclude_bases.txt';
> my $current_base = 'base.txt';
> my $output = 'new_bases.txt';
>
> open EXCLUDE, '<', $exclude_bases or die "Could not open
> '$exclude_bases' $!";
>
> my %exclude_bases;
> while ( <EXCLUDE> ) {
> next if $. == 1; # exclude header
> chomp;
> my ( $exbase_no, $keyword, $new_keyword ) = split /\|/;
> $exclude_bases{ $exbase_no } = { from => qr/\Q$keyword/, to =>
> $new_keyword };
> }
Since you're not taking into account the blank lines, you'll be
generating these warnings:
Use of uninitialized value in quotemeta at C:\test\JohnKrahn.pl line
17, <EXCLUDE> line 2.
Use of uninitialized value in hash element at C:\test\JohnKrahn.pl
line 17, <EXCLUDE> line 2.
Use of uninitialized value in quotemeta at C:\test\JohnKrahn.pl line
17, <EXCLUDE> line 4.
Use of uninitialized value in hash element at C:\test\JohnKrahn.pl
line 17, <EXCLUDE> line 4.
>
> close EXCLUDE;
>
> open BASE, '<', $current_base or die "Could not open '$current_base'
> $!";
> open OUT, '>', $output or die "Could not open '$output' $!";
>
> while ( <BASE> ) {
> my ( $base_no, $name, $description ) = split /\|/;
> if ( exists $exclude_bases{ $base_no } ) {
> $description =~
> s/$exclude_bases{$base_no}{from}/$exclude_bases{$base_no}{to}/g;
> $_ = join '|', $base_no, $name, $description;
> }
> print OUT;
> }
Again, blank lines are not taken into account, but no warnings since
the printing is being handled within the conditional block.
Since a complete solution, to what appears to be a homework question,
has already been provided, I guess I'll show mine.
#!/usr/bin/perl
use warnings;
use strict;
my %base;
open (my $new, '>', 'new_bases.txt') || die "new_bases.txt <$!>";
open (my $exclude, '<', 'exclude_bases.txt') || die "exclude_bases.txt
<$!>";
open (my $base, '<', 'base.txt') || die "base.txt <$!>";
while (<$base>) {
next if /^\s*$/; # skip over blank lines
print and next if $. == 1; # print header
chomp;
my @fields = split /\|/;
$base{$fields[0]} = [EMAIL PROTECTED];
}
close $base;
while (<$exclude>) {
next if /^\s*$/; # skip over blank lines
chomp;
my @fields = split /\|/;
if ( exists $base{$fields[0]} and $fields[1] eq $base{$fields[0]}
[2]) {
$base{$fields[0]}[2] = $fields[2];
# if you want to retain the empty lines between records,
# you can use "\n\n" in the print statement,
# or reassign the output record separator
print $new join('|', @{$base{$fields[0]}}), "\n";
}
}
close $exclude;
close $new;
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