array reading problem

jeah has asked for the wisdom of the Perl Monks concerning the following question:

Question (script at end of these notes):

* Why does my script give a result of '1' if I comment out line 6, using lines 4, 8 and 10?

* The script prints all my content correctly and completely if I comment out lines 4 and 8, using only lines 6 and 10.

The + signs in my script was automatically generated by this site, it's not part of my script. Thanks very much in advance for any help.

What I want to do:

Access a file's records whose individual attributes are delimited by pipes, the records themselves are separated by carriage returns/new line characters.

Desired Sequence:

1. Assign the file to a variable

2. Assign specific attributes of each record to various variables

3. For each record, pass the values in these variables into a T-SQL statement that updates/inserts various SQL Server tables.

Peripheral Notes:

- I'm running Perl on WinXP

- I already have the proper DBI module installed and code for the database connection and data manipulations

- The entire file's records are as follows (verbatim in content and format as the file's):

Baw|Vao|111 Noa St||NewYork|NY|10012|2123456789|123456789

Vca|Wxr|384 Mkl Ln|Xillo|CrrntStt|CT|05506|1015567781|1015567782

- In my script (for testing item 1 only), the file's content is also hardcoded for testing (line 6), it includes the following to mimic the actual file's format: . "\n" . my script follows:

#!/usr/xyz/perl -w
use strict;

my @r = open(DATFH, 'C:\begperl\my scripts\cdata.txt') or die "File pr
+ob:  $! \n";

#my @r = "Bao|Voa|321 st||New York|NY|2120001356|9172804972" . "\n" . 
+"Vca|Wxr|384 Mkl Ln|Xillo|Crrnt Stt|CT|05506|1015567781|1015567782";

close DATFH;

print @r;
[download]

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Re: array reading problem by rdfield (Priest) on Nov 23, 2008 at 08:33 UTC
You're assigning the result of the open to the array, rather than reading the file: `open(DPATH,"..."); my @r = <DPATH>; ...` [download] rdfield	[reply] [d/l]
Re: array reading problem by linuxer (Curate) on Nov 23, 2008 at 13:28 UTC
As rdfield already mentioned, your problem is in the assignment of open()'s result to your array @r. When reading the file's content, remember that Perl doesn't remove the linebreaks automatically; that's up to you (use chomp() for that): `# ... @r = <DATFH>; chomp @r;` [download] Instead of reading the complete file into an array (and into the memory) you can read linewise: `#!/usr/bin/perl use strict; use warnings; my $file = 'data.txt'; open my $datfh, '<', $file or die "$file: open(ro) failed: $!\n"; while ( my $line = <$datfh> ) { chomp $line; my @fields = split /\\|/, $line; # work with your data fields } close $datfh or die "$file: close(ro) failed: $!\n";` [download] update: paragraph tags and text added; update2: typo fixed; thanks johngg	[reply] [d/l] [select]
Re^2: array reading problem by johngg (Canon) on Nov 23, 2008 at 18:08 UTC
You have a small but significant typo in your code. `while ( my $line <$datfh> ) {` [download] Should be `while ( my $line = <$datfh> ) {` [download] Cheers, JohnGG	[reply] [d/l] [select]
Re: array reading problem by jeah (Novice) on Nov 24, 2008 at 05:15 UTC
ah, so that's what it was, thanks very much everyone for pointing out the problems, really appreciate your quick feedback. :)	[reply]


No such thing as a small change
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