The Question is:
Is there a way to determine if a file is in a "readable" format? In other
words, not an image or executable, but in a text file format (source code, txt
files, etc...) ?
The Answer is :
Not with any particular certainty, in the general case.
Various examinations could be used to approximate the decision whether
(or not) a file is printable. Obvious considerations include the RMS
record structure, the character set used within the records, and the
filename extension, but this approach is clearly an imperfect and even
moderately complex proposition, and one that will not be entirely
There are certainly cases where various attributes will indicate it is
very unlikely that the contents of a particular file are printable.
For example, files with obvious binary charactersets, invalid embedded
ANSI escape sequences, and file extensions such as .EXE would all
tend to indicate that the file is not printable.
Accordingly, it would be easier to decide which files are likely not
printable than to decide which are.