You may have received this error: -eq: unary operator expected, or a similiar error. The issue in most cases is that you probably haven’t initialized the variable before checking for its value, which happens if you have loops or redirects which miss the initialization.
Joel G Mathew, known in tech circles by the pseudonym Droidzone, is an opensource and programming enthusiast.
His favorite pastime is grappling with GNU compilers, discovering newer Linux secrets, writing scripts, hacking roms, and programs (nothing illegal), reading, blogging. and testing out the latest gadgets.
When away from the tech world, Dr Joel G. Mathew is a practising ENT Surgeon, busy with surgeries and clinical practise.