Path: utzoo!utgpu!watmath!iuvax!bsu-cs!ibmbin From: creps@silver.bacs.indiana.edu (Steve Creps) Newsgroups: comp.binaries.ibm.pc Subject: v02i004: zerodisk, erases unused disk blocks Summary: zerodisk.arc, erases unused disk blocks Message-ID: <6250@bsu-cs.UUCP> Date: 20 Mar 89 23:00:15 GMT Sender: ibmbin@bsu-cs.UUCP Followup-To: comp.binaries.ibm.pc.d Lines: 239 Approved: dhesi@bsu-cs.bsu.edu X-Submissions-to: ibmpc-binaries@bsu-cs.bsu.edu X-Questions-to: ibmpc-binaries-request@bsu-cs.bsu.edu Checksum: 382390648 (Verify with "brik", report brik bugs to me -- R.D.) Posting-number: Volume 02, Issue 004 Originally-from: creps@silver.bacs.indiana.edu (Steve Creps) Submitted-by: creps@silver.bacs.indiana.edu (Steve Creps) Archive-name: zerodisk/zerodisk.uue This is a fairly simple program I wrote to zero out those disk blocks which have been released when files were deleted, but still contain the contents of the deleted files. I wanted it to make it easier to search my hard disk for lost blocks if the (future) need might arrive, but others may want to use it to keep sensitive but no longer used data safe. Disk blocks which are currently used by files are not affected. Steve Creps, Indiana University, Bloomington creps@silver.bacs.indiana.edu (129.79.1.6) {inuxc,rutgers,uunet!uiucdcs,pur-ee}!iuvax!silver!creps creps@iubacs.bitnet (forwarded) [ Includes C source. Apparently compiled with Microsoft C. Considering what the program does, it is rather large (8 K) after compilation. Here's a small batch file that achieves a similar result. Call it "zerodisk.bat", and before running it create a small (about 1 K) file called "zerofile" containing whatever you want to write into the unused blocks. It will create a huge file called "newfile" that will use up all the available space on disk. :loop copy /b newfile+zerofile newfile goto loop Checksums obtained with the 4.3BSD "sum" or System V "sum -r" command. checksum size (bytes) file (between BEGIN--cut and END--cut lines) 62247 11637 this uuencoded posting checksum size (bytes) file 5944 8423 zerodisk.arc -- R.D. ] zerodisk part01/01 BEGIN--cut here--cut here begin 644 zerodisk.arc M&@A:15)/1$E32RY#`%Y>!`,``&82>*9J*W<$```,+U2`T%-&SALR:>:LT0&B M8)@Y94#4<1. 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