Here's a quick-and-dirty patch for shred (fileutils-4.1) so it can verify
data with the -V option, useful for checking hard disks and other media.
It also fixes a compile error when compiling for i386 (and no i686 or higher).
According to the man page, shred can shred stdout, but on FreeBSD 2.2.8 and
GNU/Linux (red hat 6.0) I get the following error:
sean@x16 [/home/sean/fileutils-4.1] src/shred -
src/shred: -: invalid file type
Sean
437a438
> int verify; /* -V flag: verify data */
447a449
> {"verify", no_argument, NULL, 'V'},
476a479
> -V, --verify read data after writing it\n\
807c810
< #if __GNUC__ >= 2 && (__i386__ || __alpha__)
---
> #if __GNUC__ >= 2 && (__i686__ || __alpha__)
834c837
< # if __i386__
---
> # if __i686__
863c866
< #else /* !(__i386__ || __alpha__) */
---
> #else /* !(__i686__ || __alpha__) */
868c871
< #endif /* !(__i386__ || __alpha__) */
---
> #endif /* !(__i686__ || __alpha__) */
1061c1064,1065
< struct isaac_state *s, unsigned long k, unsigned long n)
---
> struct isaac_state *s, unsigned long k, unsigned long n,
> struct Options const *flags)
1070a1075
> word32 v[ISAAC_WORDS * 3]; /* Multiple of 4K and of pattern size */
1072a1078
> word32 v[1024 * 3]; /* Multiple of 4K and of pattern size */
1150a1157,1164
>
> /*
> * With the --verify option set, we want to know about bad
> * media, so we bail out.
> */
>
> if (flags->verify) return -1;
>
1164a1179,1204
>
> /*
> * If --verify is set, we need to read the data to see if it's
> * OK.
> */
>
> if (flags->verify && ssize)
> {
> if (lseek (fd, (off_t) (offset + soff), SEEK_SET) == -1)
> {
> error (0, errno, "%s: lseek", qname);
> return -1;
> }
>
> if (ssize != read (fd, (char *) v, ssize) )
> {
> error (0, errno, "%s: read", qname);
> return -1;
> }
>
> if (memcmp (r + soff, v, ssize) )
> {
> error (0, 0, _("%s: verify failed"), qname);
> return -1;
> }
> }
1494c1534
< if (dopass (fd, qname, &size, passarray[i], s, i + 1, n) < 0)
---
> if (dopass (fd, qname, &size, passarray[i], s, i + 1, n, flags) < 0)
1506c1546
< if (dopass (fd, qname, &size, 0, s, flags->n_iterations + 1, n) < 0)
---
> if (dopass (fd, qname, &size, 0, s, flags->n_iterations + 1, n, flags) < 0)
1707c1747,1751
< fd = open (name, O_WRONLY | O_NOCTTY);
---
> if (flags->verify)
> fd = open (name, O_RDWR | O_NOCTTY);
> else
> fd = open (name, O_WRONLY | O_NOCTTY);
>
1780c1824
< while ((c = getopt_long (argc, argv, "fn:s:uvxz", long_opts, NULL)) != -1)
---
> while ((c = getopt_long (argc, argv, "fn:s:uvxzV", long_opts, NULL)) != -1)
1788a1833,1836
> break;
>
> case 'V':
> flags.verify = 1;
