This is really too silly. There seems to be no consistent way to get the size of a file (in bytes) on multiple platforms. Here is a solution that works in bash on Linux (tested under Debian and Ubuntu) and BSD (tested under OSX):
# Echo's size of a file (first argument).
# Tested under Linux (Debian) and BSD (OSX).
function filesize() {
echo $(stat --format=%s "$1" 2>/dev/null || stat -f '%z' "$1" 2>/dev/null)
}
# Example usage:
echo $(filesize readme.txt)
