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We have a server running Centos 5.11, Apache 2.2 and default perl. Running scripts through suexec is working "just fine", but I have installed perlbrew so that I can install a load of extra modules without interferring with it.

I have created a simple perl script to test:

#!/usr/bin/perl
print "Content-type: text/html\n\n";
print "perl: ". $^X . "\n";

When run through apache+suexec, it outputs, as expected:

Hello, world! perl: /usr/bin/perl

But, when I change the shebang line to:

#!/root/perl5/perlbrew/perls/perl-5.22.1/bin/perl

and run the same way, I get an internal server error, and the apache error log shows:

suexec failure: could not open log file
fopen: Permission denied
Premature end of script headers: test.cgi

but running at the command line is fine:

# ./test.cgi 
Content-type: text/html
Hello, world!
perl: /root/perl5/perlbrew/perls/perl-5.22.1/bin/perl

I've tried all sorts of things. I did wonder if it's a "PATH" issue, but apache docs say "On 2.2, the PATH environment variable cannot be set using Setenv."

The suexec errors usually seem to be caused by dos/unix encoding - but that's not an issue here.

Might it be an issue with the way I've installed perlbrew? Should it be as a different user (as apache)? different location (under /var/www)?

Any other suggestions welcomed!

Rich Lucking
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  • You're not using the PATH, so no, it's not a PATH issue. – ikegami Jan 09 '16 at 19:50
  • It doesn't sound like `suexec` is even getting to the point where it tries to launch `perl`. It's trying to open a log file when it fails. – ikegami Jan 09 '16 at 19:51
  • Thanks - I did wonder if the path was a red herring? Do you know what log file it might be trying to open? suexec.log has a "cmd: index.cgi" line, with no error. I can't understand how just changing the #! line would cause such issues! – Rich Lucking Jan 09 '16 at 20:21
  • Well, there's only one mentioned in the docs – ikegami Jan 09 '16 at 20:32

1 Answers1

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Solved it - your nudge got me in the right direction.

This was a clue:

# suexec -V
 -D AP_DOC_ROOT="/var/www"
 -D AP_GID_MIN=100
 -D AP_HTTPD_USER="apache"
 -D AP_LOG_EXEC="/var/log/httpd/suexec.log"
 -D AP_SAFE_PATH="/usr/local/bin:/usr/bin:/bin"
 -D AP_UID_MIN=500
 -D AP_USERDIR_SUFFIX="public_html"

I reinstalled perlbrew, changing the root:

# export PERLBREW_ROOT=/usr/local/bin/perlbrew
# perlbrew install perl-5.22.1

then changed the script to:

#!/usr/local/bin/perlbrew/perls/perl-5.22.1/bin/perl

and bingo:

Hello, world! path: /usr/local/bin/perlbrew/perls/perl-5.22.1/bin/perl

Rich Lucking
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