Re: Testing sub-module existence

Check out the $@ variable which contains the contents of any errors incurred while running eval()

# foo.pm
package foo;

sub 123 { print "this is an invalid sub name" }

qq(The End);

# script.pl
eval "require foo;";
die("ack - $@") if $@;

__output__

ack - syntax error at foo.pm line 5, near "qq(The End)"
Compilation failed in require at (eval 1) line 1.
[download]

HTH

_________ broquaint

Comment on Re: Testing sub-module existence Download Code

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Re: Testing sub-module existence by loosifer (Novice) on May 07, 2002 at 19:10 UTC
Hmm, this worked the first time, but fails the second time. That is, imagine the following situation (which roughly mirrors my own): `sub connect { if (eval { require Net::LDAPS; } and ! $@) { $ldap = Net::LDAPS->new($_[0]); } else { $ldap = Net::LDAP->new($_[0]); } return $ldap; } sub auth { $ldap = connect($_[2]); $ldap->bind($_[0],$_[1]) and return $ldap; } ($dn,$pass,$host) = @ARGV; auth($dn,$pass,$host) or die "auth failed\n"; $ldap = connect($host); $ldap->bind($dn,password=>$pass) ...` [download] In my case, the auth and connect routines are both in a library which I use for a lot of different scripts, so I needed them to be generically useful; I can't always guarantee that the connect routine won't be run multiple times in the same script. If I only run connect once, everything works fine, but if I run it twice, then the second time it doesn't record a failure, because Net::LDAPS has already failed to compile but is registered in %INC anyway. Is there some kind of way to collect this information, or am I going to have to store a $::HAVESSL variable or something, which I hate? And thanks for the quick response.	[reply] [d/l]

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Re: Testing sub-module existence
by loosifer (Novice) on May 07, 2002 at 19:10 UTC

sub connect
{
   if (eval { require Net::LDAPS; } and ! $@)
   {
      $ldap = Net::LDAPS->new($_[0]);
   }
   else
   {
      $ldap = Net::LDAP->new($_[0]);
   }
   return $ldap;
}

sub auth
{
   $ldap = connect($_[2]);
   $ldap->bind($_[0],$_[1]) and return $ldap;
}

($dn,$pass,$host) = @ARGV;
auth($dn,$pass,$host) or die "auth failed\n";
$ldap = connect($host);
$ldap->bind($dn,password=>$pass)
...
[download]

In my case, the auth and connect routines are both in a library which I use for a lot of different scripts, so I needed them to be generically useful; I can't always guarantee that the connect routine won't be run multiple times in the same script.

If I only run connect once, everything works fine, but if I run it twice, then the second time it doesn't record a failure, because Net::LDAPS has already failed to compile but is registered in %INC anyway.

Is there some kind of way to collect this information, or am I going to have to store a $::HAVESSL variable or something, which I hate?

And thanks for the quick response.

[reply]
[d/l]