Require - Module inclusion

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

Replies are listed 'Best First'.
Re: Require - Module inclusion by ikegami (Patriarch) on Mar 16, 2007 at 07:02 UTC
It's fine, except `require` never returns false. On error, it throws an exception. Also, `\:\:` would be more readable as `::`. `use constant PATH => 'XX/XDC/'; my $change=PATH."raja"; require("$change.pm"); $change=~ s{/}{::}g; $change->new();` [download]	[reply] [d/l] [select]
Re: Require - Module inclusion by qsl (Scribe) on Mar 16, 2007 at 06:28 UTC
whether following block is valid This is valid as long as it works as you have expected. perl is very intelligent enough to understand this. what is the use of doing like that ?	[reply]
Re: Require - Module inclusion by siva kumar (Pilgrim) on Mar 16, 2007 at 07:06 UTC
Hi kulls, I am getting the following error while try to run the above code. I have created raja.pm in XX/XDC directory. `use constant PATH => 'XX/XDC/'; my $change=PATH."raja"; require("$change.pm") \|\| die "$!"; $change=~ s/\//\:\:/g; $obj = $change->new(); print $obj; Output: ------- Can't locate object method "new" via package "XX::XDC::raja" (perhaps +you forgot to load "XX::XDC::raja"?) at xyz.pl.` [download] But the below is working fine and resulting the object reference. `unshift(@INC,"XX/XDC"); require raja; $obj = raja->new(); print $obj; output: ------- raja=HASH(0x8f38d1c)` [download]	[reply] [d/l] [select]
Re^2: Require - Module inclusion by Anonymous Monk on Mar 16, 2007 at 08:27 UTC
`package XX::XDC::raja;` [download]	[reply] [d/l]
Re^2: Require - Module inclusion by kulls (Hermit) on Mar 16, 2007 at 11:42 UTC
Hi, Thanks for mail. I have tried your suggestion. it's not working for me. I found that `raja` is hardcoded . Can you please try like this ? `my $pack='raja.pm'; unshift(@INC,"XX/XDC"); require "$pack"; $obj = $pack->new(); print $obj;` [download] Let me know your comments. -kulls	[reply] [d/l] [select]
Re^3: Require - Module inclusion by agianni (Hermit) on Mar 16, 2007 at 14:48 UTC
A couple of comments: I would avoid using a relative path in your @INC. That seems rather fragile. Actually, avoid using relative paths in general. Insted of unshifting onto @INC, use lib, it does exactly that. Generally, we name our module files with a .pm extension, but our package/class names don't include the .pm, so you'll need to address that when you call new on the package name Given those suggestions, try this: `# assume this is hard coded my $package = 'raja.pm'; use lib qw ( /full/path/to/XX/DC ); # get the package name without the .pm my ( $class ) = split /\./, $package; # require by package name require $package; # call new on the class (raja) my $obj = $class->new(); print $obj;` [download] `perl -e 'split//,q{john hurl, pest caretaker};print join q{},map{@_[$_]}q{00061314041703012005120710111907081505211622192409}=~/\d{2}/g;'`	[reply] [d/l] [select]
Re: Require - Module inclusion by pgor (Beadle) on Mar 16, 2007 at 20:59 UTC
`require` will translate a package spec to a path, but it needs to be a bareword. That can simplify your method, as long as you remember to use the string version of `eval`: `use constant BASE => 'XX::XDC'; my $change = BASE . '::raja'; eval "require $change"; die($@) if ($@); $change->new();` [download] pg	[reply] [d/l] [select]
Re: Require - Module inclusion by valdez (Monsignor) on Mar 18, 2007 at 09:54 UTC
I would use UNIVERSAL::require: `use UNIVERSAL::require; my $class = 'XX::XDC::raja'; require $class or die "can't require '$class': $@"; $class->new;` [download] Ciao, Valerio	[reply] [d/l]


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