HACKER Nora wrote:
Hello,
Hello,
I would be really glad if someone could give me a hint to my following
problem: I have a script that runs smoothly on AIX5.3, installed Perl
is 5.8.8. Now I need it to run on AIX6.1, Perl is 5.8.8 as well, but I
experience a strange, differing behaviour. I have a sub-function that
greps for a certain process in the ps list. In the course of this
script this function is called twice. On AIX5.3, I get the same result
(process running or not) both times, on AIX6.1 I get "process running"
at the first call of the sub, but error -1 at the second call. Could
this be an OS behaviour problem?
Here are the code snippets:
#################
# This is the main function of my script (doing DB backups/restore)
sub backup {
#[... some other subs ...]
appl( 'start', 'D', checkStatus('D') ); # starts the Oracle DB if
checkStatus returns that DB is not running; gives correct result
#[... some other subs ...]
my $dbvers = getDBVersion(); # gets the application version from the DB;
on AIX6.1 this produces os level error -1
#[... some other subs ...]
}
#################
# This is the sub-function for getting the application version from the DB
sub getDBVersion {
my $fnc = ( caller 0 )[$CALLER_ID];
Where did $CALLER_ID come from?
DEBUG("$fnc - DBType: $dbtype\n");
Where did $dbtype come from?
my $vdb = $empty;
my $adb = $empty;
Where did $empty come from? What is $empty supposed to contain?
if ( $dbtype eq 'V' ) { # in my case FALSE, ignore
# viaMG-DB temporär umspeichern, um Version aus ApplDB ermitteln zu
können
$vdb = $db;
DEBUG("$fnc - viaMG-DB: $vdb\n");
print 'Bitte zugehörige Applikations-DB angeben: ';
INFO("$fnc - Bitte zugehörige Applikations-DB angeben: ");
$adb =<STDIN>;
chomp $adb;
$db = $adb;
Shouldn't that be:
my $db = $adb;
INFO("$fnc - DB: $db\n");
# SID setzen
$ENV{'ORACLE_SID'} = "$db";
Why are you copying $db to a string?
INFO("$fnc - ORACLE_SID: $ENV{'ORACLE_SID'}\n");
}
my $status = checkStatus('D'); #<-- this FAILS at the second execution
:-(
DEBUG("$fnc - DBStatus aus Unterfunktion checkStatus: $status\n");
my $dbvers;
if ( $status == 0 ) {
my $dbverslst = "$tmps/dbversion_$db.lst";
DEBUG("$fnc - Tempfile mit DB-Version: $dbverslst\n");
system "$sqlplus"
. ' "/as sysdba" '
. "\@$sqls/get_db_version.sql $db> /dev/null 2>&1";
You should verify that system() executed correctly.
perldoc -f system
DEBUG(
"$fnc - $sqlplus \"/as sysdba\" \@$sqls/get_db_version.sql $db\n");
if ( fgrep { /ERROR/ } $dbverslst ) {
The UNIX fgrep utility does not use regular expressions so this is a bit
confusing. Why aren't you just using perl's built-in grep() here? And
why use grep() at all on a list with only one element?
if ( $dbverslst =~ /ERROR/ ) {
$dbvers = giveDBVersion();
} else {
DEBUG("$fnc - Kein Error aus get_db_version.sql.\n");
}
my @dbversgrep;
my $fh_dbverslst = IO::File->new("< $dbverslst");
You should *always* verify that files opened correctly. Why aren't you
just using perl's built-in open() here?
open my $fh_dbverslst, '<', $dbverslst or die "Cannot open
'$dbverslst' because: $!";
if ( ! $fh_dbverslst ) {
That is not the correct way to test a filehandle.
perldoc -f fileno
Or just test the return value of open().
perldoc perlopentut
perldoc -f open
LOGDIE("$fnc - $dbverslst konnte nicht gelesen werden!\n");
}
while (<$fh_dbverslst>) {
chomp;
$_ =~ s/ //g;
Why "$_ =~" here and not below?
if (/[\d.]/s) { push @dbversgrep, $_ }
The /s option only affects the . special character which you are not using.
}
undef $fh_dbverslst;
$dbvers = $dbversgrep[0];
INFO("$fnc - Datenbank-Version (aus DB): $dbvers\n");
if ( -e "$dbverslst" ) {
Why are you copying $dbverslst to a string? Why test for (-e) existence
when unlink(), through $!, will tell you if $dbverslst doesn't exist?
unlink $dbverslst
or INFO(
"$fnc - Datei $dbverslst konnte nicht gelöscht werden:
$!\n");
}
} else {
INFO( "$fnc - Datenbank $db ist down.\n" );
print "Datenbank $db ist down.\n";
$dbvers = giveDBVersion();
}
if ( $dbtype eq 'V' ) {
$db = $vdb; # viaMG-DB wieder als Haupt-DB einsetzen
# SID setzen
$ENV{'ORACLE_SID'} = "$db";
Why are you copying $db to a string?
INFO("$fnc - ORACLE_SID: $ENV{'ORACLE_SID'}\n");
}
return $dbvers;
}
#################
# This is the sub-function for checking whether the Oracle DB (and/or Tuxedo)
is running
sub checkStatus {
my ( $art ) = @_;
my $fnc = ( caller 0 )[$CALLER_ID];
Where did $CALLER_ID come from?
DEBUG("$fnc - Übergabeparameter: @_\n");
my $status;
if ( $art eq 'D' ) {
system "ps -ef |grep -v grep |grep dbw |grep -q $db";
Where did $db come from?
my $test = `ps -ef |grep -v grep |grep dbw |grep $db`; # print
grepped ps list for debugging
print "Test: $test\n";
$status = $?>> $SHIFT_ERROR;
Where did $SHIFT_ERROR come from? You should put this line *directly*
*after* the line that sets $?. You are probably getting the status from
the shell that the back-ticks run, but print() might affect its value.
If you want the status from system() you should only use $? right after
system() has completed.
When you use system() you should verify that it executed correctly.
perldoc -f system
if ( $status == 0 ) {
INFO("$fnc - DB-Status: $status = DB $db is running\n");
} else {
INFO("$fnc - DB-Status: $status = DB $db is not running\n");
}
} elsif ( $art eq 'T' ) {
system "ps -ef |grep -v grep |grep -w BBL |grep -wq $tux";
Where did $tux come from?
$status = $?>> $SHIFT_ERROR;
if ( $status == 0 ) {
INFO("$fnc - Tuxedo-Status: $status = Tuxedo $tux is running\n");
} else {
INFO("$fnc - Tuxedo-Status: $status = Tuxedo $tux is not
running\n");
}
}
return $status;
}
#################
# This is the script output with the grepped ps list output for debugging
purposes:
oracle:/opt/magna/wartung> dbmove.pl -m s -d MVRSTDB
Default-Tuxedo: mvrst
Return code: 0
Test: oracle 299118 1 0 08:57:47 - 0:00 ora_dbw1_MVRSTDB
oracle 765990 1 0 08:57:47 - 0:00 ora_dbw0_MVRSTDB
DB MVRSTDB is running
Return code: -1
Test: oracle 299118 1 0 08:57:47 - 0:00 ora_dbw1_MVRSTDB
oracle 765990 1 0 08:57:47 - 0:00 ora_dbw0_MVRSTDB
DB MVRSTDB is not running
[...]
Any hints in which direction to investigate???
Do you have utilities like pgrep on AIX? Does your version of ps
support the -o option?
In some shells, instead of doing:
ps -ef | grep -v grep | grep dbw
You can just do:
ps -ef | grep d[b]w
John
--
Any intelligent fool can make things bigger and
more complex... It takes a touch of genius -
and a lot of courage to move in the opposite
direction. -- Albert Einstein
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