Script to Check for Control Characters in File

Here is how to check for and display lines from a text file that contain control characters except for line endings (which are also control characters!).

$ grep "[^[:print:]]" infile | cat -nvt

Here is a simple script that will output a message if a text file contains any control characters other than line endings.

#!/bin/bash

if grep "[^[:print:]]" infile > /dev/null 2>&1
then
    printf "Control characters present in filen"
else
    printf "No control characters in filen"
fi

This should work in all locales.