Home/ Questions/Q 7580115
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-30T17:50:08+00:00

First off, I am not a Unix expert by any stretch, so please forgive

  • 0

First off, I am not a Unix expert by any stretch, so please forgive a little naiveity in my question.

I have a requirement to list the unencrypted files in a given directory that potentially contains both encryped and unencrypted files.

I cannot reliably identify these files by file extension alone and was hoping someone in the SO community might be able to help me out.

I can run:

file * | egrep -w 'text|XML'

but that will only identify the files that are either text or XML. I could possibly use this if I can’t do much better as currently the only other files in the directry are text or XML files but I really wanted to identify all unencrypted files whatever type they may be.

Is this possible in a single line command?

EDIT: the encrypted files are encrypted via openSSL

The command I use to unencrypt the files is:

openssl -d -aes128 -in <encrypted_filename> -out <unencrypted_filename>
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Your problem is not a trivial one. The solaris file command uses “magic” – /etc/magic. This is a set of rules to attempt to attempt to determine what flavor a file is. It is not perfect.

    If you read the /etc/magic file, note that the last column is verbiage that is in the output of the file command when it recognizes something, some structure in a file.

    Basically the file command looks at the first few bytes of a file, just like the exec() family of system calls does. So, #/bin/sh in the very first line of a file, in the first characters of the line, identifies to exec() the “command interpreter” that exec() needs to invoke to “run” the file. file gets the same idea and says “command text” “awk text” etc.

    Your issues are that you have to work out what types of files you are going to see as output from file. You need to spend time delving into the non-encrypted files to see what “answers” you can expect from file. Otherwise you can run file over the whole directory tree and sort out all of what you think are correct answers.

    find /path/to/files -type f -exec file {} \; | nawk -F':' '!arr[$2]++'  > outputfile

    This gives you a list of distinct answers about what file thinks you have. Put the ones you like in a file, call it good.txt

    find /path/to/files -type f -exec file {} \; > bigfile
nawk -F':' 'FILENAME=="good.txt" {arr$1]++}
          FILENAME=="bigfile" {if($2 in arr) {print $1}} ' good.txt bigfile > nonencryptedfiles.txt

    THIS IS NOT 100% guaranteed. file can be fooled.

    • 0