Yifan Zhang questions

• A case in which both test -n and test -z are true
• How to make an array in shell?
• How do I write a shell script to remove the unzipped files in a wrong directory?
• What's the difference b/w __raw_readl/__raw_writel and readl/writel in linux kernel?
• Why is this code reentrant but not thread-safe
• How to add line number for output, prompt for line, then act based on input?

Yifan Zhang answers