01What is the Unix philosophy?
02What does the shebang (#!) line do in a shell script?
03What is the difference between $? and $$ in shell scripting?
04What is the purpose of file permissions in Unix/Linux?
05What does the pipe (|) operator do in shell commands?
06What is the difference between 'source script.sh' and './script.sh'?
07What is the purpose of /dev/null in Unix/Linux?