• file(1)
• uudecode(1)
• xxd
• tr
• gzip, xzip, bzip2, zip, tar & ar
• chmod
• sort
• cpio
• rev

Some files are not readable or writeable. Use chmod to change the permissions to allow yourself to read and write. The command to change permissions is chmod. To give yourself reading and writing abilities, and give no one else, do chmod 600.