在PHP脚本中调用时，无法通过Perl建立MySQL连接

Question

I'm creating a connection to a MySQL database within a Perl script, called by a PHP script. Here are the 2 scripts:

Perl:

#!/usr/bin/perl
# script name = MyCode.pl
use DBI;
my $data_source = q/dbi:mysql:name:localhost/;
my $user = q/myname/;
my $pwd = q/pword/;

print "before...\n";
# Connect!
$dbhandle= DBI->connect($data_source,$user,$pwd) or die "can't connect
       $data_source: $DBI::errstr \n";
print "...after \n";

PHP:

<?php
 // script name = Test.php
 $myResult=shell_exec("perl /path/MyCode.pl");
 echo $myResult;
?>

---

When executed on the command line, Test.php prints "before..." and "...after" and the DB connection is indeed established within the Perl code. However, when Test.php is executed from my (Chrome) browser, all that prints is "before..." and no connection is made. And no error message is displayed.

Why is there success on the command line but not from a web server?

Answer 1

Yes, PHP shell_exec() function doesn't capture STDERR.

To debug your code, you can add a 2>&1 at the end of system command to redirect STDERR to STDOUT :

$myResult = shell_exec("perl /path/script.pl 2>&1");

Also, you can setup the DBI module to die if some error occurs at runtime:

$dbh = DBI->connect($data_source,$user, $pwd, { RaiseError => 1, PrintError => 0}) or die $DBI::errstr;

Answer 2

My first guess: from PHP you execute it with "perl /path/MyCode.pl"

The shell opened by Apache are under different user than yours and that user does not perl in it path.

Try using Perl from full path: "/full/path/to/perl /path/MyCode.pl"

FYI: Executing script with perl "scriptname" is not a good practice. Instead define a full path in to your Perl in the shebang and always start your script using the full path. This way you could avoid errors like this.

Regards, Andras

Answer 3

Problem fixed...I needed correct path specification: this is done (on godaddy) by using:

use cPanelUserConfig;

in the Perl script to access the DBD::mysql module that I installed.