- NAME
- DESCRIPTION
  - FreeBSD core dumps from readdir_r with ithreads
  - $^X doesn't always contain a full path in FreeBSD
- AUTHOR

# NAME

perlfreebsd - Perl version 5 on FreeBSD systems

# DESCRIPTION

This document describes various features of FreeBSD that will affect how Perl version 5 (hereafter just Perl) is compiled and/or runs.

## FreeBSD core dumps from readdir_r with ithreads

When perl is configured to use ithreads, it will use re-entrant library calls in preference to non-re-entrant versions. There is a bug in FreeBSD's `readdir_r` function in versions 4.5 and earlier that can cause a SEGV when reading large directories. A patch for FreeBSD libc is available (see http://www.freebsd.org/cgi/query-pr.cgi?pr=misc/30631 ) which has been integrated into FreeBSD 4.6.

## $^X doesn't always contain a full path in FreeBSD

perl sets `$^X` where possible to a full path by asking the operating system. On FreeBSD the full path of the perl interpreter is found by using `sysctl` with `KERN_PROC_PATHNAME` if that is supported, else by reading the symlink /proc/curproc/file. FreeBSD 7 and earlier has a bug where either approach sometimes returns an incorrect value (see http://www.freebsd.org/cgi/query-pr.cgi?pr=35703 ). In these cases perl will fall back to the old behaviour of using C's argv[0] value for `$^X`.

# AUTHOR

Nicholas Clark <nick@ccl4.org>, collating wisdom supplied by Slaven Rezic and Tim Bunce.

Please report any errors, updates, or suggestions to perlbug@perl.org.