How to check if the file is a binary file and read all the files which are not?

Question

How can I know if a file is a binary file?

For example, compiled c file.

I want to read all files from some directory, but I want ignore binary files.

Answer 1

grep

Assuming binary means file containing non-printable characters (excluding blank characters such as spaces, tabs or new line characters), this may work (both BSD and GNU):

$ grep '[^[:print:][:blank:]]' file && echo Binary || echo Text

^{Note: GNU grep will report file containing only NULL characters as text, but it would work correctly on BSD version.}

^{For more examples, see: How do I grep for all non-ASCII characters.}