linux - verifing some arguments in bash -

I'm verifying one in BASH

  if [! ((-e $ f) || ($ # -lt2) || (-D $ F));; Again exit 0f   
 I am trying to see if the file exists or if it is a directory or if enough arguments pass through the terminal I can do this Or should it be done in any other way?   
 
 
 Reject anything that is not a simple file, in that case, instead of the -e If you use -f, then testing for a directory is unnecessary.  
  If [[! -f "$ f" || $ # -lt2]]; Then exit 0f   
 By the way, if this is an error, you should get away from something other than 0-0, in most cases, success indicates; Exit 1 will be better.