I'm coding in PHP and threads are a bit out of my league. I'd like to run the same script in parallel. Say my script runs for 2 minutes, and I run it every minute during a cronjob. What happens? Does the first one fall over when the second one runs, or do they just both hum along?
Both jobs will work in parallel as two different processes. Just be careful they do not use the same resource at the same time (say, a file). This can cause some nasty problems which are hard to debug.
Both jobs "just hum along".