Every time I need to do a little bash scripting involving if statements, checking for empty variables and non-existent files et.c. I find myself hitting google for some simple bash manual or guide.

Often these are way too long and complicated to quickly answer the question I have at hand.

So, I was thinking that there must be some command or man page that covers the basic bash syntax (for things like if-statements, checks for empty variables, non-existent files etc) in a short and accessible manner. I'm sure I just havent found out the command (man bash doesn't seem to be it).

Where can I find that?