building Perl: a few Configure questions

[j3]

Going through the Configure steps while building Perl on Debian (-Dprefix=/opt/perl-5.8.8), I'm hoping someone can explain or comment on few parts that I was unsure about, or that just seemed curious.

1. ``Does your kernel have *secure* setuid scripts? [n]''

   What does this mean? How do I discover if my OS supports these? How does this setting affect the resulting Perl?

2. ``Installation prefix to use for add-on modules and utilities? (~name ok) [/opt/perl-5.8.8]''

   What modules/utils are being referred to here? I don't think it's for site_perl stuff, because that gets mentioned in the subsequent configuration question.

3. ``Pathname where the public executables will reside? (~name ok) [/opt/perl-5.8.8/bin]
   Directory /opt/perl-5.8.8/bin doesn't exist. Use that name anyway? [n]''

   I went to a different terminal window and created that bin directory, then continued on with the config. Is that the usual way this step goes? Seems odd that the default isn't just for the build to automatically create the necessary bin directory.

4. ``You are using the GNU C Library version 2.3.6
   
   nm probably won't work on the GNU C Library.''

   Just curious about this one: why would nm have an issue with extracting symbols from the GNU C library?

Finally, during the ``make test'' stage, I noticed a number of tests that were skipped. Besides the win32, threading, and 64-bit ones (all unrelated to my platform/configuration), these juicy-looking ones turned up as being skipped:

lib/ExtUtils/t/xs.........................skipping test on this platform

lib/Net/Ping/t/200_ping_tcp...............skipping test on this platform
lib/Net/Ping/t/250_ping_hires.............skipping test on this platform
lib/Net/Ping/t/300_ping_stream............skipping test on this platform
lib/Net/Ping/t/400_ping_syn...............skipping test on this platform
lib/Net/Ping/t/410_syn_host...............skipping test on this platform

lib/Net/t/ftp.............................skipping test on this platform
lib/Net/t/nntp............................skipping test on this platform
lib/Net/t/smtp............................skipping test on this platform

lib/Test/Harness/t/nonumbers..............skipping test on this platform
lib/Test/Harness/t/pod....................skipping test on this platform
lib/Test/Harness/t/prove-globbing.........skipping test on this platform
lib/Test/Harness/t/prove-switches.........skipping test on this platform

Should any of those be ringing a missing dependencies bell?

[shmem]

1. ``Does your kernel have *secure* setuid scripts? [n]''

What does this mean? How do I discover if my OS supports these? How does this setting affect the resulting Perl?

Read perlsec. Secure setuid scripts means the kernel invokes the setuid interpreter for the script with a filehandle to that script opened. It affects perl in its way to handle setuid scripts: read it from the special file descriptor, or complain. For more info on the underlying problem see also the hacking FAQ, question 8. Linux does not have secure setuid scripts; that kernel ignores the setuid bit on scripts.

[shandor]

``Pathname where the public executables will reside? (~name ok) /opt/perl-5.8.8/bin Directory /opt/perl-5.8.8/bin doesn't exist. Use that name anyway? n''

I would assume that perl will create this directory (if it doesn't exist) if you say yes and have the correct permissions.

[ysth]

Installation prefix to use for add-on modules and utilities? (~name ok) [/opt/perl-5.8.8]

What modules/utils are being referred to here? I don't think it's for site_perl stuff, because that gets mentioned in the subsequent configuration question.

This is the question for the siteprefix config variable. It's usually a directory that contains bin and lib subdirectories. The answer you give here can provide the prefix of the default value for several other config variables: sitescript, sitebin, sitelib, siteman1dir, siteman3dir.

[j3]

Thanks for the great replies folks. Much appreciated.