I am fairly new with perl and apache and seem to be having a small problem with my code.
I have 3 files:
hw.pm
package hw;
sub calc {
my $num1 = shift;
my $num2 = shift;
return $num1 + $num2;
}
1;
startup.pl
use lib qw(path to where hw.pm is located);
1;
hel.pl
#!/usr/bin/perl -w
use hw;
use CGI qw(:standard);
print header;
my $ans = calc(5,4);
print $ans;
I have no problem restarting apache but when I access hel.pl from the browser I get an error Can't locate hw.pm in #INC
Should the startup.pl have already included it in #INC? Or am I missing something?
I am using perl v5.10.1 and Apache2 v2.2.16
Perl is not finding hw.pm.
Try copying this line from startup.pl
use lib qw(path to where hw.pm is located);
to hel.pl, replacing the "use hw;" there. But first make sure the path is correct.
#INC - The array #INC contains the list
of places to look for Perl scripts to
be evaluated by the do EXPR , require
, or use constructs. It initially
consists of the arguments to any -I
command line switches, followed by the
default Perl library, probably
"/usr/local/lib/perl", followed by
".", to represent the current
directory.
I managed to solve it. initially i had this in my apache2.conf:
PerlRequire startup.pl
but after adding this code:
<Directory /var/www>
SetHandler perl-script
PerlResponseHandler ModPerl::Registry
PerlOptions +ParseHeaders
Options +ExecCGI
</Directory>
I was able to access my modules from hel.pl
Thanks guys for your help.
Related
This simple .pl script is supposed to grab all of the images in a directory and output an HTML — that when opened in a browser — displays all of the images in that dir at their natural dimensions.
From the mac command line, I want to just say perl myscript.pl and have it run.
… It used to run on apache in /cgi-bin.
#!/usr/bin/perl -wT
# myscript.pl
use strict;
use CGI;
use Image::Size;
my $q = new CGI;
my $imageDir = "./";
my #images;
opendir DIR, "$imageDir" or die "Can't open $imageDir $!";
#images = grep { /\.(?:png|gif|jpg)$/i } readdir DIR;
closedir DIR;
print $q->header("text/html"),
$q->start_html("Images in $imageDir"),
$q->p("Here are all the images in $imageDir");
foreach my $image (#images) {
my ($width, $height) = imgsize("$image");
print $q->p(
$q->a({-href=>$image},
$q->img({-src=>$image,
-width=>$width,
-height=>$height})
)
);
}
print $q->end_html;
Perl used to include the CGI module in the Standard Library, but it was removed in v5.22 (see The Long Death of CGI.pm). Lots of older code assumed that it would always be there, but now you have to install it yourself:
$ cpan CGI
Perl used to include the CGI module in the Standard Library, but it was removed in v5.22. Lots of older code assumed that it would always be there, but now you have to install it yourself.
The corelist program that comes with Perl is handy for checking these things:
$ corelist CGI
Data for 2020-03-07
CGI was first released with perl 5.004, deprecated (will be CPAN-only) in v5.19.7 and removed from v5.21.0
I handle this sort of thing by using the extract_modules program from my Module::Extract::Use module. Otherwise, I end up installing one module, then run again and discover another one to install, and so on:
$ extract_modules some_script.pl | xargs cpan
There's another interesting point for module writers. For a long time, we'd only list the external prerequisites in Makefile.PL. You should list even the internal ones now that Perl has a precedent for kicking modules out of the Standard Library. Along with that, specify a dependency for any module you actually use rather than relying it being in a particular distribution.
And, I was moving legacy programs around so much that I wrote a small tool, scriptdist to wrap the module infrastructure around single-file programs so I could install them as modules. The big win there is that cpan and similar tools install the prereqs for you. I haven't used it in a long time since I now just start programs as regular Perl distributions.
I'm new to both Perl and its feature of .lib.
I made this simple subroutine and saved it as a file with an extension of .lib
sub shorterline {
print "Content-type: text/html\n\n";
}
1;
As I tried to insert the subroutine into the Perl file with an extension of .cgi below, it doesn't work somehow:
#!/usr/bin/perl
require 'mysubs.lib';
&shorterline;
print "Hello, world!";
I gave the .cgi the chmod permission, but the .cgi still doesn't work, what seem to be the problem ?
Your descriptions of what the problem is are rather unclear.
it doesn't work somehow
the .cgi still doesn't work
Without knowing what problems you're seeing, it's hard to know what the problem is. But I tried copying your code and running the program from the command line and I got this error message:
Can't locate mysubs.lib in #INC (#INC contains: ...)
So I think you are using a recent version of Perl and are running up against this change:
Removal of the current directory (".") from #INC
The perl binary includes a default set of paths in #INC. Historically it has also included the current directory (".") as the final entry, unless run with taint mode enabled (perl -T). While convenient, this has security implications: for example, where a script attempts to load an optional module when its current directory is untrusted (such as /tmp), it could load and execute code from under that directory.
Starting with v5.26, "." is always removed by default, not just under tainting. This has major implications for installing modules and executing scripts.
If this is the problem, then you can fix it by adding the script's directory to #INC as follows:
use FindBin qw( $RealBin );
use lib $RealBin;
before your call to require. If that doesn't solve your problem, perhaps you would consider sharing a little more detail about the problems that you are experiencing.
I have made my own perl modules(pm files),named test.pm
package test;
use Exporter;
use strict;
use File::Basename qw(basename dirname);
use Cwd qw(abs_path);
use File::Path qw(make_path);
use FindBin qw($Bin $Script);
BEGIN {
our #ISA = qw(Exporter);
our #EXPORT = qw(mkdirOrDie);
our $VERSION = 1.0;
}
sub mkdirOrDie
{
my ($dir) = #_ ;
if(!-d $dir){
make_path($dir);
$dir=abs_path($dir);
# timeLog("Directory Created: $dir");
}
}
and I tried to install this module as follows,
h2xs -AX -n test
perl Makefile.PL
make
make install
there is no error,and I copy the test.pm to /usr/lib64/perl5/5.10.0/,but when i call sub function using test, an error has occurred,
Undefined subroutine &main::mkdirOrDie called at /to/my/path/main.pl line 92
is there something i ignored?
It's unclear at which point things started to go wrong for you.
Firstly, test.pm is a bad name for a Perl module. Perl modules should have names that begin with upper case letters (and Test.pm is already taken).
You should run h2xs before writing your code - as it generates a module skeleton for you fill in. I hope it hasn't overwritten your code with an almost empty file! It's also worth noting that most people stopped using h2xs many years ago. These days we have tools like Module::Starter.
Then, running, make install (which you need to do with root permissions - so usually with sudo) is what installs your module into the system libraries. There should be no need to run that cp command afterwards.
As for why your code doesn't find the module, there are many possible reasons. Are you using Perl 5.10 or do you have other Perl versions installed? What does the code look like that you are trying to use? Does test.pm still include the code you think it does?
Need more information to be much help here.
If I know that a certain perl module is installed on a system, eg. MyCompany::Database::Utils, how can I inspect the perl code of this module?
Find the source code file with whatever means your OS provides.
If you're looking for a properly installed module, you can use perldoc -l to find the file or perldoc -m to print the file (thanks #ThisSuitIsBlackNot, #mob):
perldoc -l List::Util
perldoc -m List::Util
If your module is MyCompany::Database::Utils, you know it must be in a path MyCompany/Database/Utils.pm below one of the paths in #INC.
You can list the default #INC paths with
perl -MData::Dumper -e 'print Dumper(\#INC);'
If you are on a system with mlocate (such as most Linux/BSD distros), you can also find the file with
locate MyCompany/Database/Utils.pm
If you want to look into a distribution to see the full source (e.g. to find XS code, README, unit tests etc.), you can use cpanminus' --look flag:
cpanm --look DateTime
Perl can find the module, so let Perl tell you where it found it!
perl -e'
my $p = $ARGV[0];
$p =~ s{::}{/}g;
$p .= ".pm";
require $p;
print "$INC{$p}\n";
' MyCompany::Database::Utils
If the module contains POD, you can use the following shortcut:
perldoc -l MyCompany::Database::Utils
If that doesn't find the module, it could be that the script that uses MyCompany::Database::Utils manipulates #INC to allow it to find the module. If so, add the following to your script:
END {
my $p = "MyCompany::Database::Utils";
$p =~ s{::}{/}g;
$p .= ".pm";
print "$INC{$p}\n";
}
The built-in hash %INC documented in perldoc perlvar relates each module's .pm source file to its file system location
If you have
use MyCompany::Database::Utils;
then perl will search for a file like MyCompany/Database/Utils.pm relative to any of the directories listed in array #INC and, if it is found, will put its absolute location into the %INC hash
To find where each module has been located, you can simply dump the entire hash using Data::Dump or Data::Dumper. But if you're really only interested in one module then you can examine the relevant hash element. A statement like this
print "$INC{'MyCompany/Database/Utils.pm'}\n";
will show the absolute path where that .pm file was found and loaded
I'm unable to execute the HTML::Template function in the CGI.
I'm following a simple tutorial that I found here: http://metacpan.org/pod/HTML::Template
I created a new file on my server in the home path as test.tmpl.
I created a new file named frt.cgi ... (is that the issue here? should it be a different file extention??)
#!/usr/local/bin/perl -w
use HTML::Template;
# open the html template
my $template = HTML::Template->new(filename => '/test.html');
# fill in some parameters
$template->param(HOME => $ENV{HOME});
$template->param(PATH => $ENV{PATH});
# send the obligatory Content-Type and print the template output
print "Content-Type: text/html\n\n", $template->output;
I've modified the 1st line to reflect my host provided program path for perl. I don't know what the -w does I just know I've tried this with and without it. Also I've tried changing the code a bit like this:
use warnings;
use strict;
use CGI qw(:standard);
use HTML::Template;
I've searched...
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE+&submit=search
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE+PERL&submit=search
Yet I still do not see the answer.
I even searched google for .TMPL Encoding because I thought there may be some special type needed. Please help.
If you look in your server logs, you'll probably see an error message along the lines of:
HTML::Template->new() : Cannot open included file /test.html : file not found.
You need to provide the path on the file system, not a URI relative to the generated document.
First, you likely specified the wrong path - change /test.html to test.html.
Also, it is possible that there is no $ENV{HOME} variable in your system so set up flag die_on_bad_params to 0:
my $template = HTML::Template->new(
filename => 'test.html',
die_on_bad_params => 0,
);
Also, don't forget to mark your Perl file as executable by chmod 755.
Option -w makes Perl to enable warnings, so there is no point to write use warnings; afterwards.
You can check what Perl command line options do by using module B::Deparse, like this ($^W variable disables/enables warnings):
perl -w -MO=Deparse -e "print;"
This would print:
BEGIN { $^W = 1; }
print $_;