Check if a file exists and has a size greater than X 

[[ $(find /path/to/file -type f -size +51200c 2>/dev/null) ]] && echo true || echo false

January 9, 2014 — bashoneliners

Explanation

  • The find takes care two things at once: checks if file exists and size is greater than 51200.
  • We redirect stderr to /dev/null to hide the error message if the file doesn't exist.
  • The output of find will be non-blank if the file matched both conditions, otherwise it will be blank
  • The [[ ... ]] evaluates to true or false if the output of find is non-blank or blank, respectively

You can use this in if conditions like:

if [[ $(find /path/to/file -type f -size +51200c 2>/dev/null) ]]; do
    somecmd
fi
file-management conditionals
echo true find false