To find and replace ASCII control codes or nonprintable characters using the sed command, you will need to use a regular expression that matches the specific control code or character that you want to replace.
For example, to replace the ASCII horizontal tab character (\t) with a space, you can use the following sed command:
sed 's/\t/ /g' input.txt > output.txt
This will replace all occurrences of the horizontal tab character in the input.txt file with a space, and save the modified output to the output.txt file. The g flag at the end of the sed expression indicates that the replacement should be performed globally, replacing all occurrences of the tab character.
You can use a similar approach to replace other ASCII control codes or nonprintable characters. For example, to replace the ASCII line feed character (\n) with a space, you can use the following sed command:
sed 's/\n/ /g' input.txt > output.txt
To find and replace ASCII control codes or nonprintable characters in a specific range, you can use the [:cntrl:] character class in a regular expression. For example, to replace all ASCII control codes with a space, you can use the following sed command:
sed 's/[