Exit code

Bash exit code

• http://www.faqs.org/docs/abs/HTML/exitcodes.html#EXITCODESREF
• http://www.freebsd.org/cgi/man.cgi?query=sysexits&sektion=3

die v.s. exit?

• http://stackoverflow.com/questions/3601106/how-to-terminate-a-program-in-perl-exit-or-die

Unix signals (seems to be referred to as "Fatal error signal" in http://www.faqs.org/docs/abs/HTML/exitcodes.html#EXITCODESREF)

• http://unixhelp.ed.ac.uk/CGI/man-cgi?signal+7

Unix error code

• http://www-numi.fnal.gov/offline_software/srt_public_context/WebDocs/Errors/unix_system_errors.html

system() v.s. backticks (``) in perl