in reply to Return Value Problem

That code "should work" as long as $rarray is actually a reference to an array. Since you don't tell us what errors you are seeing, we can't tell what's wrong.

however, there is a much more intuitive way of solving your problem: just return a list: 

 
sub somesub {
  my $x = 1;
  my $y = 2;
  return ($x,$y);
}

my ($r1,$r2) = somesub();

print "r1: $r1, r2: $r2\n";
__END__
r1: 1, r2: 2

[download]
"What should it profit a man, if he should win a flame war, yet lose his cool?"

Replies are listed 'Best First'.
Re^2: Return Value Problem
by Ronnie (Scribe) on Oct 14, 2004 at 10:35 UTC
    I've changed my code to reflect your suggestion :- 
    #!/usr/bin/perl -w
#
use DBI ;
use strict ;
#
sub chk_cals {
#
#########################################################
# This Perl subroutine can be used to call an SQLPLUS   #
# script. Should this routine run to completition a 1   #
# script by Perl. Should this routine run to completion #
# (True) is returned. A failure at any stage will exit  #
# the calling script and send an appropriate Email to   #
# all interested parties.                               #
#########################################################
#
#########################################################
# Ensure variable privacy by use of the strict pragma.  #
#########################################################
#
use strict ;
use lib '/home/interface/scripts/Perl_Modules' ;
use ACC_Various ("update_report", "end_it", "mail", "mail_log") ;   
use ACC_Oracle ;
#
#####################################
# Parameter Error Boolean           #
#####################################
#
my $PARAMETER_ERROR = 0 ;
my $VALID_DB        = 0 ;
#
#########################################################
# This routine must be supplied with 4 parameters or it #
# will fail with a parameter error.                     #
#########################################################
#
#####################################
# Parameter declarations            #
#####################################
#
my $to         = undef ;
my $from       = undef ;
my $DB_name    = undef ;
my $logfile    = undef ;
#
#####################################
#       DBI Handles                 #
#####################################
#
my $dbh = undef ;
my $sth = undef ;
#
#####################################
#       DBI Error variables         #
#####################################
#
#  $DBI::err ;
#  $DBI::errstr ;
#  $DBI::state ;
#
#####################################
#      DBI Variables (hashes)       #
#####################################
#
my %attr = (
    PrintError => 0,   
    RaiseError => 0
) ;
#
################################################
# Test that the requisite number of parameters #
# have been supplied. (There MUST be 4).       #
################################################
#
if (@_ != 4) {
 print "\n\tSub::run_sqlplus -  MUST be supplied with minimum of 4 par
+ameters!" ;
 $PARAMETER_ERROR = 1 ;
}
else {
#
###############################################
# Declare parameter names                     #
###############################################
#
 $to         = $_[0] ;
 $from       = $_[1] ;
 $logfile    = $_[2] ;
 $DB_name    = $_[3] ;
#
}
#
###############################################################
# Set up variables                                            #
###############################################################
# Date and time variables for headings in Emails/logfile etc. #
###############################################################
#
my ($min, $hour, $day, $mon, $year) = (localtime) [1,2,3,4,5] ;
my $date = sprintf("%02d/%02d/%04d", $day, $mon +=1, $year += 1900);
my $time = sprintf("%02d%02d" , $hour , $min) ;
my $ptime = sprintf("%02d:%02d" , $hour , $min) ;
#
##############################
# Variables (Common scalars) #
##############################
#
my $trace_file = 'DBI_chk_cals_trace.log' ;
# 
#############################
#
my $username        = undef ;
my $password        = undef ;
my $DB_pass         = undef ;
my $ENV_info        = undef ;
#
#####################################
# Array Variables                   #
#####################################
#
my @fields         = undef ;
my @return_values  = () ;
my @Valid_DB_Names = qw(isw-test isw-live isw-teach) ;
#
# Common or garden scalars
#############################
#
my $record_count    = 0 ;
my $bcount          = 0 ;
my $ecount          = 0 ;
#

######################################
#           Hash Table               #
######################################
#
my %uid_HashLookup = (
   'isw-live'  => "/etc/oracleLIVEuid",
   'isw-test'  => "/etc/oracleTESTuid",
   'isw-teach' => "/etc/oracleTEACHuid"
);

my %ENVHashLookup = (
   'isw-live'  => "ISWLIVE",
   'isw-test'  => "ISWTEST",
   'isw-teach' => "ISWTEACH",
);
#
#####################################
#        mail_log variables.        #
#####################################
#
my $script              = 'chk_cals' ;
my $mail_msg            = 1 ;
my $null                = "none" ;
my $subject             = "Urgent - $script Failed!" ;
my $msg                 = "This should change according to failure!" ;
my $text                = "\tUnable to write the following to $logfile
+ :-\n\n" ;
my $topline             = "\n\tThe error message is -\n\n" ;
#
###########################################################
# Processing                                              #
###########################################################
#
###########################################################
#            Is it a valid Database name                  #
###########################################################
#
   foreach (@Valid_DB_Names) {
      if ($DB_name eq $_) {
         $VALID_DB = 1 ;
      }
   }
#
   if (! $VALID_DB) {
      $msg = "Db name supplied - $DB_name - is not known to this scrip
+t!" ;
      &update_report("$logfile","$msg",1,3,1) or &end_it($mail_msg,$to
+,$from,$subject,$msg,$text,$logfile) ;
      print "\n\t$msg\n" ;
      $PARAMETER_ERROR = 1 ;
   }
   else
    {
     $ENV_info = $ENVHashLookup{$DB_name} ;
#
###############################################################
#              Check that DB_pass exists                      #
###############################################################
#
     $DB_pass = $uid_HashLookup{$DB_name} ;
     if ( !-e $DB_pass) {
       $msg = "File $DB_pass does not exist!" ;
       &update_report("$logfile","$msg",1,3,1) or &end_it($mail_msg,$t
+o,$from,$subject,$msg,$text,$logfile) ;
       print "\n\t$msg\n\n" ;
       $PARAMETER_ERROR = 1 ;
     }
    }
#
$msg = "Oracle/Perl DBI (chk_cals) run on $date at $ptime." ;
&update_report("$logfile","$msg",1,3,1) or &end_it($mail_msg,$to,$from
+,$subject,$msg,$text,$logfile) ;
#
###########################################################
#               Set up the relevant profile               #
###########################################################
#
$msg = "Failed to run ACC_Oracle_profile" ;
&ACC_Oracle_profile("$ENV_info") or &end_it($mail_msg,$to,$from,$subje
+ct,$msg,$null,$logfile) ;
#
$msg = "ACC_Oracle_profile completed for $DB_name Environment" ;
&update_report("$logfile","$msg",1,1,1) or &end_it($mail_msg,$to,$from
+,$subject,$msg,$text,$logfile) ;
#
###########################################################
#           P A R A M E T E R   E R R O R S               #
###########################################################
#
   if ($PARAMETER_ERROR) {
     $msg = "\n\tScript $script fails with parameter errors!\n" ;
     print "$msg" ;
     print "\t*****************************************\n" ;
     print "\t* Contact Analyst in Team 1 - Urgently! *\n" ;
     print "\t*****************************************\n" ;
     return 0 ;
   }
#
#####################################################
# Read the Password file                            #
#####################################################
#
   $msg = "Failed to OPEN $DB_pass for Input." ;
   open INF, "<$DB_pass" or &end_it($mail_msg,$to,$from,$subject,$msg,
+$text,$logfile) ;
#
   $msg = "File $DB_pass opened for input." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   $msg = "Processing I/P file :: $DB_pass." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;

   while (<INF>) {
    $record_count ++ ;

    chomp ;

    @fields = split /\//, $_ ;

    $username = $fields[0] ;
    $password = $fields[1] ;

   }
#
   $msg = "Failed to CLOSE $DB_pass." ;
   close INF or end_it($mail_msg,$to,$from,$subject,$msg,$text,$logfil
+e) ;
#
   $msg = "Closed input file :: $DB_pass." ;
   &update_report("$logfile","$msg",1,1,1) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   if ($record_count != 1) {
    $msg = "\n\tThere were too many records in the $DB_pass file!" ;
    print "$msg" ;
    print "\t*****************************************\n" ;
    print "\t* Contact Analyst in Team 1 - Urgently! *\n" ;
    print "\t*****************************************\n" ;
    &end_it($mail_msg,$to,$from,$subject,$msg,$topline) ;
   }
#
###########################################################
#         Test for & remove any existing trace_file       #
###########################################################
#
   if (-e $trace_file) {
     $msg = "DBI - Failed to unlink old $trace_file" ;  
     unlink $trace_file or
            &end_it($mail_msg,$to,$from,$subject,$msg,$null,$logfile) 
+;
#
###########################################################
#         Update logfile                                  #
###########################################################
#
   $msg = "DBI - Old $trace_file unlinked." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   }
#
###########################################################
#         Set tracing                                     #
###########################################################
#
   DBI->trace(2, $trace_file) ;
#
###########################################################
#         Update logfile                                  #
###########################################################
# 
   $msg = "DBI - Tracing switched on." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
###########################################################
#         Connect to the DB                               #
###########################################################
#
   $msg = "DBI - Failed to connect to $DB_name" ;
   $dbh = DBI->connect( "dbi:Oracle:$DB_name", "$username", "$password
+", \%attr) or
                    &end_it($mail_msg,$to,$from,$subject,$msg,$null,$l
+ogfile) ;
#
###########################################################
#         Update logfile                                  #
###########################################################
#
   $msg = "DBI - User $username connected to $DB_name." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
###########################################################
#         Prepare SQL                                     #
###########################################################
#
   $msg = "DBI - Preparing SQL (SELECT (1)...........)." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   $msg = "\n\tDBI failed to prepare the supplied code(1)\n" ;
   $sth = $dbh->prepare( "select count(*) 
                          from   O_YEARS y,
                                 O_CALENDARS c
                          where  c.CAL_ID = y.YRS_CAL_ID
                          and    c.CAL_TYPE ='BUDGET'
                          and    to_char(y.YRS_END_DATE,'YYYY') like (
+to_char(sysdate,'YYYY')+1)") or
   &end_it($mail_msg,$to,,$from,$subject,$msg,$null,$logfile) ;
#
   $msg = "DBI - prepared SQL (SELECT (1)..............)." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
###########################################################
#         Execute the prepared SQL                        #
###########################################################
#
   $msg = "\n\tFailed to execute SQL (SELECT (1)..............).\n" ;
   $sth->execute() or
       &end_it($mail_msg,$to,$from,$subject,$msg,$null,$logfile) ;

   $msg = "DBI - SQL (SELECT (1)...............) executed." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
###########################################################
# Retrieve the returned rows of data                      #
###########################################################
#
   $record_count = 0 ;
#
   while ( $bcount = $sth->fetchrow_array() ) {
     print "\n\tField bcount = $bcount.\n" ;
     $record_count ++ ;
   }
#
   print "\n\tThe record count(bcount) returned was $record_count.\n" 
+; 
#
   $msg = "DBI - Preparing SQL (SELECT (2)...........)." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   $sth = $dbh->prepare( "select count(*) 
                          from   O_YEARS y,
                                 O_CALENDARS c
                          where  c.CAL_ID=y.YRS_CAL_ID
                          and    c.CAL_TYPE='EXTERNAL'
                          and    to_char(y.YRS_END_DATE,'YYYY') like t
+o_char(sysdate,'YYYY')") or
   &end_it($mail_msg,$to,,$from,$subject,$msg,$null,$logfile) ;
#
   $msg = "DBI - prepared SQL (SELECT (2)..............)." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
###########################################################
#         Execute the prepared SQL                        #
###########################################################
#
   $msg = "\n\tFailed to execute SQL (SELECT (2)..............).\n" ;
   $sth->execute() or
       &end_it($mail_msg,$to,$from,$subject,$msg,$null,$logfile) ;

   $msg = "DBI - SQL (SELECT (2)...............) executed." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
###########################################################
# Retrieve the returned rows of data                      #
###########################################################
#
   $record_count = 0 ;
#
   while ( $ecount = $sth->fetchrow_array() ) {
     print "\n\tField ecount = $ecount.\n" ;
     $record_count ++ ;
   }
#
   print "\n\tThe record count(ecount) returned was $record_count.\n" 
+; 
#
###########################################################
#         Finish the extract tidily                       #
###########################################################
#
   $msg = "\n\tDBI failed to FINISH tidily\n"  ;
   $sth->finish() or &end_it($mail_msg,$to,$from,$subject,$msg,$text,$
+logfile) ;
#
###########################################################
#         Disconnect from the DB                          #
###########################################################
#
   $msg = "\n\tDBI - Failed to disconnect from $DB_name." ;
   $dbh->disconnect() or
         &end_it($mail_msg,$to,$from,$subject,$msg,$null,$logfile) ;
#
###########################################################
#         Update logfile                                  #
###########################################################
#
   $msg = "DBI - User $username disconnected from $DB_name." ;
   &update_report("$logfile","$msg",1,1,0) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   $msg = "<********** End Of Report **********>" ;
   &update_report("$logfile","$msg",2,3,1) or &end_it($mail_msg,$to,$f
+rom,$subject,$msg,$text,$logfile) ;
#
   return ($bcount,$ecount)
}
#
#######################################################
#                     Variables                       #
#######################################################
#
my $to       = 'ronniec@it.aberdeen.net.uk' ;
my $from     = 'Buckethead' ;
my $logfile  = 'xxrc_test_DBI_special.log' ;
my $DB_name  = 'isw-test' ;
my $result   = 0 ;
my $count    = 0 ;
my @response = () ;
#
#####################################
#        mail_log variables.        #
#####################################
#
my $script              = 'chk_cals' ;
my $mail_msg            = 0 ;
my $null                = "none" ;
my $subject             = "Script $script completion details" ;
my $msg                 = "See attachment for completions details" ;
my $text                = "\tUnable to write the following to $logfile
+ :-\n\n" ;
my $row                 = undef ;
#
print "\n\t<************ SOR $script ***************>\n" ;
#
my ($bcount,$ecount) = &chk_cals("$to","$from","$logfile","$DB_name") 
+;
#
print "\n\tScalar bcount :: $bcount\n" ;
#
print "\n\tScalar ecount :: $ecount\n" ;
#
$result = &mail_log($to,$from,$subject,$msg,$logfile) ;
#
if (! $result )
 {
   $msg = "\tFailed to send completions Email!\n" ;
   $subject = "Urgent - $0 Failed!" ; 
   print "$msg" ;
   print "\t*****************************************\n" ;
   print "\t* Contact Analyst in Team 1 - Urgently! *\n" ;
   print "\t*****************************************\n" ;
   exit(99) ;
 }
#
$mail_msg = 1 ;
#
print "\n\t<************ EOR $script ***************>\n" ;

    [download]
    but it still doesn't work. When printing out the $bcount/$ecount variables in the calling script I get the standard error - 
     
                <***** EOR ACC_Oracle_profile *****>
 
        Field bcount = 1.
 
        The record count(bcount) returned was 1.
 
        Field ecount = 1.
 
        The record count(ecount) returned was 1.
Use of uninitialized value in concatenation (.) or string at xxrcdbi.p
+l line 447
.
 
        Scalar bcount ::
Use of uninitialized value in concatenation (.) or string at xxrcdbi.p
+l line 449
.
 
        Scalar ecount ::
 
        Sub::mail_log - Ends without errors.
 
        <************ EOR chk_cals ***************>

    [download]
    This is the problem I'm encountering whichever method I use - any ideas? Ronnie "Bamboozeled" Cruickshank
[reply]
[d/l]
[select]
      Well, that's expected :-) to paraphrase your code: 
      sub somesub {
 # ...
 # ...

 # loop until $ecount is false
 # it is actually undocumented what this means
 # fetchrow_array is supposed to be called in list
 # context like so
 #
 #      ($ecount) = $sth->fetchrow_array();
 #
  
 while ( $ecount = $sth->fetchrow_array() ) { 
   # ..
 }
 # $ecount is undef here, probably (see above)

 return $ecount;
}

      [download]
      the return statement is working perfectly, but your variable s will always be false (certainly not some "count").
      "What should it profit a man, if he should win a flame war, yet lose his cool?"
[reply]
[d/l]
      Sorry to have been such a complete ****ing! novice but I see what is wrong - bcount/ecount are being destroyed when the fetchrow_array is exhausted!! Back to the lowest cells for me!! Ronnie
[reply]

In Section Seekers of Perl Wisdom