mod_perl ignoring changed to $ENV{{PATH}?

I've narrowed down to a simple script a problem where it looks like
when running under mod_perl, it does not support changes to the
$ENV{PATH} variable - it does require the assignment to avoid the
tainting, but then any assignment itself does not take effect - I
added /usr/local/bin to PATH, but am unable to execute commands in
that folder when running under mod_perl.

Could not find anything about this in the mod_perl web pages, but a
Usenet search seems to suggest that mod_perl only honors PerlSetEnv
PATH in config, and does not honor PATH changes in the script? That
does not sound right, what about the cases where a PATH change is
needed for some scripts only, so a global PerlSetEnv would be too
much.

Example - for testing, I copied /bin/echo to /usr/local/bin/echo, and
then ran this script - it runs fine when run under the shell, but when
run under Apache + mod_perl, it fails.

Script:
#!/usr/bin/perl -Tw

print "Content-type: text/plain\n\n";

$ENV{PATH} = "/bin:/usr/bin:/usr/local/bin:";
foreach ( "echo", "myecho", "/usr/local/bin/myecho") {
print "------ Testing command '$_'\n";
my $string = `$_ testing execution of '$_'`;
print " failed to execute '$_', \$? is $?/" . ($? >> 8) . " : $!
\n"
if ($? != 0);
print " \$string is: $string\n";
}

Shell output (perl -Tw script)
Content-type: text/plain

------ Testing command 'echo'
$string is: testing execution of echo

------ Testing command 'myecho'
$string is: testing execution of myecho

------ Testing command '/usr/local/bin/myecho'
$string is: testing execution of /usr/local/bin/myecho

Web page output - this fails to execute myecho without the path:
------ Testing command 'echo'
$string is: testing execution of echo

------ Testing command 'myecho'
failed to execute 'myecho', $? is 32512/127 :
$string is:
------ Testing command '/usr/local/bin/myecho'
$string is: testing execution of /usr/local/bin/myecho

Re: mod_perl ignoring changed to $ENV{{PATH}?

On Jan 15, 3:30 pm, bwooster47 wrote:
> I've narrowed down to a simple script a problem where it looks like
> when running undermod_perl, it does not support changes to the
> $ENV{PATH} variable - it does require the assignment to avoid the
> tainting, but then any assignment itself does not take effect - I
> added /usr/local/bin to PATH, but am unable to execute commands in
> that folder when running undermod_perl.
>
> Could not find anything about this in themod_perlweb pages, but a
> Usenet search seems to suggest thatmod_perlonly honors PerlSetEnv
> PATH in config, and does not honor PATH changes in the script? That
> does not sound right, what about the cases where a PATH change is
> needed for some scripts only, so a global PerlSetEnv would be too
> much.
>
> Example - for testing, I copied /bin/echo to /usr/local/bin/echo, and
> then ran this script - it runs fine when run under the shell, but when
> run under Apache +mod_perl, it fails.
>
> Script:
> #!/usr/bin/perl -Tw
>
> print "Content-type: text/plain\n\n";
>
> $ENV{PATH} = "/bin:/usr/bin:/usr/local/bin:";
> foreach ( "echo", "myecho", "/usr/local/bin/myecho") {
> print "------ Testing command '$_'\n";
> my $string = `$_ testing execution of '$_'`;
> print " failed to execute '$_', \$? is $?/" . ($? >> 8) . " : $!
> \n"
> if ($? != 0);
> print " \$string is: $string\n";
>
> }
>
> Shell output (perl -Tw script)
> Content-type: text/plain
>
> ------ Testing command 'echo'
> $string is: testing execution of echo
>
> ------ Testing command 'myecho'
> $string is: testing execution of myecho
>
> ------ Testing command '/usr/local/bin/myecho'
> $string is: testing execution of /usr/local/bin/myecho
>
> Web page output - this fails to execute myecho without the path:
> ------ Testing command 'echo'
> $string is: testing execution of echo
>
> ------ Testing command 'myecho'
> failed to execute 'myecho', $? is 32512/127 :
> $string is:
> ------ Testing command '/usr/local/bin/myecho'
> $string is: testing execution of /usr/local/bin/myecho

This looks like a 'Taint' issue - I would check by running it without
the 'T' switch. If you want to use Taint (which you will) then you
could look at the perl5lib CPAN package which is Taint-safe

http://search.cpan.org/~nobull/perl5lib-1.02/lib/perl5lib.pm