AW: Use of uninitialized valued in concatenation....
It is not a standard perl error message. I went through mod_perl doc at http://perl.apache.org/docs/general/perl_reference/perl_reference.html#T racing_Warnings_Reports and understand that, the error message appear if one fails to pass a value to a subroutine before using. Looking through my codes, you may have noticed that, I did pass 2 arguments to the subroutine. -Ursprüngliche Nachricht- Von: Perrin Harkins [mailto:[EMAIL PROTECTED] Gesendet: Samstag, 23. August 2003 00:10 An: B. Fongo Cc: [EMAIL PROTECTED] Betreff: Re: Use of uninitialized valued in concatenation On Fri, 2003-08-22 at 17:23, B. Fongo wrote: I have a file (output_tab.pm) that I use to generate tables dynamically. Even though it serves its purpose, it goes on generating this error: Script_name.pl: Use of uninitialized value in concatenation (.) or string at output_tab.pm line 42. This is a standard perl error message. It is not related to mod_perl. You can look in the perldiag man page for a more complete explanation. - Perrin -- Reporting bugs: http://perl.apache.org/bugs/ Mail list info: http://perl.apache.org/maillist/modperl.html
AW: AW: Use of uninitialized valued in concatenation....
Oh yes I did. I always try my script on the command line to ensure the
syntax are ok before running them on the web server with mod_perl. So
the error has to do with mod_perl. Perhaps you may want to take a look
of some examples:
I have a file (output_tab.pm) that I use to generate tables dynamically.
Even though it serves its purpose, it goes on generating this error:
Script_name.pl: Use of uninitialized value in concatenation (.) or
string at output_tab.pm line 42.
I went through this section of mod_perl docs und thought Ive understood
it, but I cant feature out the error. Ill appreciate any help.
Below is my module and a script that triggers such error.
#
output_tab.pm
#-
# Modulname: output_tab.pm
#-
use strict;
package output_tab;
use vars qw(@ISA @EXPORT);
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(output_tab);
use db_Verbindungen;
sub output_tab{
my ($dbh,$abfrage,$columnspan, $sth,@table_head,@table_data);
($abfrage, @table_head) = @_;
$columnspan = @table_head;
print qq(table width=95% border=1 cellspacing=1
cellpadding=1 align=center);
print qq(tr bgcolor=#a9a9a9);
foreach (@table_head){
print qq(th$_/th);
}
print qq(/tr);
# Erbnisse Anzeigen
$dbh = db_Verbindungen;
$sth = $dbh-prepare($abfrage);
$sth-execute();
print qq(tr);
while(@table_data = $sth-fetchrow_array){
#my $table_data;
foreach (@table_data)
{
print qq(td bgcolor='#d0d0d0'$_/td); # Here is line 42
}
print qq(/tr);
}
print qq(trtd colspan=$columnspan
bgcolor='#d0d0d0'nbsp;/td/tr);
print qq(/table);
$sth-finish();
$dbh-disconnect();
}
1;
###
#!/usr/bin/perl -w
#
#Script: pakete_auflisten.pl
#=
use strict;
use db_Verbindungen;
use gui;
use output_tab;
my ($dbh,$abfrage,@table_head);
$abfrage = ('SELECT Gruppe, Paketname, Auftragsdatum, Status,
Statusmeldung FROM Gruppen_Software ORDER BY Auftragsdatum DESC');
@table_head = qw(Gruppe Paketname Auftragsdatum Status Statusmeldung);
# Aufruf der Methode top() des gui.pm Moduls.
top('Paketliste');
# At this stage i call the method output_tab with two arguements.
output_tab($abfrage,@table_head);
# Aufruf der Methode footer() des gui.pm Moduls.
footer();
#== ENDE==
Babs
-Ursprüngliche Nachricht-
Von: Sreeji K Das [mailto:[EMAIL PROTECTED]
Gesendet: Samstag, 23. August 2003 11:10
An: B. Fongo; 'Perrin Harkins'; [EMAIL PROTECTED]
Betreff: Re: AW: Use of uninitialized valued in concatenation
Did u check what's in line # 42 ? If u run the same
script with same params as stand-alone, do u see the
warning ?
Sreeji
--- B. Fongo [EMAIL PROTECTED] wrote: It is not a
standard perl error message. I went
through mod_perl doc at
http://perl.apache.org/docs/general/perl_reference/perl_reference.html#T
racing_Warnings_Reports
and understand that, the error message appear if one
fails to pass a
value to a subroutine before using. Looking through
my codes, you may
have noticed that, I did pass 2 arguments to the
subroutine.
-Ursprüngliche Nachricht-
Von: Perrin Harkins [mailto:[EMAIL PROTECTED]
Gesendet: Samstag, 23. August 2003 00:10
An: B. Fongo
Cc: [EMAIL PROTECTED]
Betreff: Re: Use of uninitialized valued in
concatenation
On Fri, 2003-08-22 at 17:23, B. Fongo wrote:
I have a file (output_tab.pm) that I use to
generate tables
dynamically. Even though it serves its purpose, it
goes on generating
this error:
Script_name.pl: Use of uninitialized value in
concatenation (.) or
string at output_tab.pm line 42.
This is a standard perl error message. It is not
related to mod_perl.
You can look in the perldiag man page for a more
complete explanation.
- Perrin
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Re: AW: Use of uninitialized valued in concatenation....
Did u check what's in line # 42 ? If u run the same script with same params as stand-alone, do u see the warning ? Sreeji --- B. Fongo [EMAIL PROTECTED] wrote: It is not a standard perl error message. I went through mod_perl doc at http://perl.apache.org/docs/general/perl_reference/perl_reference.html#T racing_Warnings_Reports and understand that, the error message appear if one fails to pass a value to a subroutine before using. Looking through my codes, you may have noticed that, I did pass 2 arguments to the subroutine. -Ursprüngliche Nachricht- Von: Perrin Harkins [mailto:[EMAIL PROTECTED] Gesendet: Samstag, 23. August 2003 00:10 An: B. Fongo Cc: [EMAIL PROTECTED] Betreff: Re: Use of uninitialized valued in concatenation On Fri, 2003-08-22 at 17:23, B. Fongo wrote: I have a file (output_tab.pm) that I use to generate tables dynamically. Even though it serves its purpose, it goes on generating this error: Script_name.pl: Use of uninitialized value in concatenation (.) or string at output_tab.pm line 42. This is a standard perl error message. It is not related to mod_perl. You can look in the perldiag man page for a more complete explanation. - Perrin Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://uk.messenger.yahoo.com/ -- Reporting bugs: http://perl.apache.org/bugs/ Mail list info: http://perl.apache.org/maillist/modperl.html
Re: AW: AW: Use of uninitialized valued in concatenation....
Am Sat, 23 Aug 2003 09:48:05 + schrieb B. Fongo:
foreach (@table_data)
{
print qq(td bgcolor='#d0d0d0'$_/td); # Here is line 42
}
as Frank already pointed out, your trouble is the uninitialized $_ value
you have in line 42 (which is exactly what the warning tells you, BTW).
the reason for this is very probably that @table_data contains items
that have not been initialized (= they have no value, not even an
empty value assigned to them). @table_data is filled from
database, so _check your database_. I bet you will find null values in
here.
if you don't want to output anything if the database delivers such a null
value simply replace your line 42 with
-CUT--
print qq(td bgcolor='#d0d0d0'$_/td) if $_;
-CUT--
if you want to output an empty line for null values, then do as Frank
suggested:
-CUT--
my $val=$_||'NULL'; print qq(td DEFANGED_bgcolor=0#d0d0d0$val/td);
-CUT--
and no, this has definitively absolute nothing to do with mod_perl, thats
just expected and normal perl behaviour.
happy hacking
udo
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Re: Re: AW: AW: Use of uninitialized valued in concatenation....
-CUT--
my $val=$_||'NULL'; print qq(td DEFANGED_bgcolor=0#d0d0d0$val/td);
-CUT--
This is not a very good solution. You would also catch the case where $_
is 0, which may should not happen. You would better do
foreach (@table_data) {
$_ = defined $_ ? $_ : NULL;
print qq(td bgcolor='#d0d0d0'$_/td); # Here is line 42
}
Basically you also simply could use the warnings pragma within this sub :
no warnings uninitialized;
greets, Marcel
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Re: Re: AW: AW: Use of uninitialized valued in concatenation....
On Sat, Aug 23, 2003 at 01:55:03PM +0200, Marcel Greter wrote: This is not a very good solution. You would also catch the case where $_ is 0, which may should not happen. You would better do Yes... I always fall into that pithole. I think this is because I find the 'defined(...) ? ... : ...' phrase is kinda ugly. Silly me, I know. $_ = defined $_ ? $_ : NULL; Still... I don't know if I like toying around with $_. Especially since you change the real array value (and not a copy) and this might cause problems later on (should you use the values somewhere else as well). But why are we talking about this on a mod_perl list. Sorry guys. --Frank -- Reporting bugs: http://perl.apache.org/bugs/ Mail list info: http://perl.apache.org/maillist/modperl.html
Re: AW: AW: Use of uninitialized valued in concatenation....
Frank Maas wrote: On Sat, Aug 23, 2003 at 01:55:03PM +0200, Marcel Greter wrote: This is not a very good solution. You would also catch the case where $_ is 0, which may should not happen. You would better do Yes... I always fall into that pithole. I think this is because I find the 'defined(...) ? ... : ...' phrase is kinda ugly. Silly me, I know. $_ = defined $_ ? $_ : NULL; perl 5.9 has introduced a new operator //= to make it spiffy, so you'd write the above as: $_ //= NULL; __ Stas BekmanJAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide --- http://perl.apache.org mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com http://modperlbook.org http://apache.org http://ticketmaster.com -- Reporting bugs: http://perl.apache.org/bugs/ Mail list info: http://perl.apache.org/maillist/modperl.html
AW: Use of uninitialized valued in concatenation....
OK Guys!
Thanks for all the contributions. All along, I thought mod_perl was
complaining that $_ isn't initialized. Most of the suggestions I got
points to the array (@table_data) in the loop. It is actually true that
the some of the values of the array are NULL.
Thanks again for all those suggestions.
Babs
-Ursprüngliche Nachricht-
Von: news [mailto:[EMAIL PROTECTED] Im Auftrag von Udo Rader
Gesendet: Samstag, 23. August 2003 13:00
An: [EMAIL PROTECTED]
Betreff: Re: AW: AW: Use of uninitialized valued in concatenation
Am Sat, 23 Aug 2003 09:48:05 + schrieb B. Fongo:
foreach (@table_data)
{
print qq(td bgcolor='#d0d0d0'$_/td); # Here is line 42
}
as Frank already pointed out, your trouble is the uninitialized $_ value
you have in line 42 (which is exactly what the warning tells you, BTW).
the reason for this is very probably that @table_data contains items
that have not been initialized (= they have no value, not even an
empty value assigned to them). @table_data is filled from
database, so _check your database_. I bet you will find null values in
here.
if you don't want to output anything if the database delivers such a
null
value simply replace your line 42 with
-CUT--
print qq(td bgcolor='#d0d0d0'$_/td) if $_;
-CUT--
if you want to output an empty line for null values, then do as Frank
suggested:
-CUT--
my $val=$_||'NULL'; print qq(td DEFANGED_bgcolor=0#d0d0d0$val/td);
-CUT--
and no, this has definitively absolute nothing to do with mod_perl,
thats
just expected and normal perl behaviour.
happy hacking
udo
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Mail list info: http://perl.apache.org/maillist/modperl.html
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