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Teach dd(1) about parity bits.

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This commit is contained in:
phk 2004-03-05 19:35:51 +00:00
parent 99a4684d72
commit d0818243a9
9 changed files with 157 additions and 21 deletions
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1
bin/dd/Makefile
View File

@ -15,6 +15,7 @@ MAINTAINER= green@FreeBSD.org
test: ${PROG}
cc ${.CURDIR}/gen.c
.for conv in ascii ebcdic ibm oldascii oldebcdic oldibm \
pareven parnone parodd parset \
swab lcase ucase
@echo testing conv=${conv}
@./a.out | \

4
bin/dd/args.c
View File

@ -299,6 +299,10 @@ static const struct conv {
{ "oldebcdic", C_EBCDIC, C_ASCII, a2e_32V },
{ "oldibm", C_EBCDIC, C_ASCII, a2ibm_32V },
{ "osync", C_OSYNC, C_BS, NULL },
{ "pareven", C_PAREVEN, C_PARODD|C_PARSET|C_PARNONE, NULL},
{ "parnone", C_PARNONE, C_PARODD|C_PARSET|C_PAREVEN, NULL},
{ "parodd", C_PARODD, C_PAREVEN|C_PARSET|C_PARNONE, NULL},
{ "parset", C_PARSET, C_PARODD|C_PAREVEN|C_PARNONE, NULL},
{ "sparse", C_SPARSE, 0, NULL },
{ "swab", C_SWAB, 0, NULL },
{ "sync", C_SYNC, 0, NULL },

20
bin/dd/dd.1
View File

@ -231,6 +231,13 @@ and
systems.
.It Cm lcase
Transform uppercase characters into lowercase characters.
.It Cm pareven , parnone , parodd , parset
Output data with the specified parity.
The parity bit on input is stripped unless
.Tn EBCDIC
to
.Tn ASCII
conversions is also specified.
.It Cm noerror
Do not stop processing on an input error.
When an input error occurs, a diagnostic message followed by the current
@ -355,6 +362,19 @@ be written to the standard error output
in the same format as the standard completion message and
.Nm
will exit.
.Sh EXAMPLES
Check that a disk drive contains no bad blocks:
.Dl dd if=/dev/ad0 of=/dev/null bs=1m
.Pp
Do a refresh of a disk drive, in order to prevent presently
recoverable read errors from progressing into unrecoverable read errors:
.Dl dd if=/dev/ad0 of=/dev/ad0 bs=1m
.Pp
Remove parity bit from a file
.Dl dd if=file conv=parnone of=file.txt
.Pp
Check for (even) parity errors on a file:
.Dl dd if=file conv=pareven | cmp -x - file
.Sh DIAGNOSTICS
.Ex -std
.Sh SEE ALSO

75
bin/dd/dd.c
View File

@ -104,6 +104,16 @@ main(int argc __unused, char *argv[])
exit(0);
}
static int
parity(u_char c)
{
int i;
i = c ^ (c >> 1) ^ (c >> 2) ^ (c >> 3) ^
(c >> 4) ^ (c >> 5) ^ (c >> 6) ^ (c >> 7);
return (i & 1);
}
static void
setup(void)
{
@ -176,29 +186,52 @@ setup(void)
if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
err(1, "truncating %s", out.name);
/*
* If converting case at the same time as another conversion, build a
* table that does both at once. If just converting case, use the
* built-in tables.
*/
if (ddflags & (C_LCASE | C_UCASE)) {
if (ddflags & (C_ASCII | C_EBCDIC)) {
if (ddflags & C_LCASE) {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = tolower(ctab[cnt]);
} else {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = toupper(ctab[cnt]);
}
if (ddflags & (C_LCASE | C_UCASE | C_ASCII | C_EBCDIC | C_PARITY)) {
if (ctab != NULL) {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = ctab[cnt];
} else {
if (ddflags & C_LCASE) {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = tolower((int)cnt);
} else {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = toupper((int)cnt);
}
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = cnt;
}
if ((ddflags & C_PARITY) && !(ddflags & C_ASCII)) {
/*
* If the input is not EBCDIC, and we do parity
* processing, strip input parity.
*/
for (cnt = 200; cnt <= 0377; ++cnt)
casetab[cnt] = casetab[cnt & 0x7f];
}
if (ddflags & C_LCASE) {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = tolower(casetab[cnt]);
} else if (ddflags & C_UCASE) {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = toupper(casetab[cnt]);
}
if ((ddflags & C_PARITY)) {
/*
* This should strictly speaking be a no-op, but I
* wonder what funny LANG settings could get us.
*/
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = casetab[cnt] & 0x7f;
}
if ((ddflags & C_PARSET)) {
for (cnt = 0; cnt <= 0377; ++cnt)
casetab[cnt] = casetab[cnt] | 0x80;
}
if ((ddflags & C_PAREVEN)) {
for (cnt = 0; cnt <= 0377; ++cnt)
if (parity(casetab[cnt]))
casetab[cnt] = casetab[cnt] | 0x80;
}
if ((ddflags & C_PARODD)) {
for (cnt = 0; cnt <= 0377; ++cnt)
if (!parity(casetab[cnt]))
casetab[cnt] = casetab[cnt] | 0x80;
}
ctab = casetab;
}

6
bin/dd/dd.h
View File

@ -95,3 +95,9 @@ typedef struct {
#define C_UNBLOCK 0x80000
#define C_OSYNC 0x100000
#define C_SPARSE 0x200000
#define C_PAREVEN 0x400000
#define C_PARODD 0x800000
#define C_PARSET 0x1000000
#define C_PARNONE 0x2000000
#define C_PARITY (C_PAREVEN|C_PARODD|C_PARSET|C_PARNONE)

18
bin/dd/ref.pareven Normal file
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@ -0,0 +1,18 @@
$FreeBSD$
00000000 00 81 82 03 84 05 06 87 88 09 0a 8b 0c 8d 8e 0f |................|
00000010 90 11 12 93 14 95 96 17 18 99 9a 1b 9c 1d 1e 9f |................|
00000020 a0 21 22 a3 24 a5 a6 27 28 a9 aa 2b ac 2d 2e af |.!".$..'(..+.-..|
00000030 30 b1 b2 33 b4 35 36 b7 b8 39 3a bb 3c bd be 3f |0..3.56..9:.<..?|
00000040 c0 41 42 c3 44 c5 c6 47 48 c9 ca 4b cc 4d 4e cf |.AB.D..GH..K.MN.|
00000050 50 d1 d2 53 d4 55 56 d7 d8 59 5a db 5c dd de 5f |P..S.UV..YZ.\.._|
00000060 60 e1 e2 63 e4 65 66 e7 e8 69 6a eb 6c ed ee 6f |`..c.ef..ij.l..o|
00000070 f0 71 72 f3 74 f5 f6 77 78 f9 fa 7b fc 7d 7e ff |.qr.t..wx..{.}~.|
00000080 00 81 82 03 84 05 06 87 88 09 0a 8b 0c 8d 8e 0f |................|
00000090 90 11 12 93 14 95 96 17 18 99 9a 1b 9c 1d 1e 9f |................|
000000a0 a0 21 22 a3 24 a5 a6 27 28 a9 aa 2b ac 2d 2e af |.!".$..'(..+.-..|
000000b0 30 b1 b2 33 b4 35 36 b7 b8 39 3a bb 3c bd be 3f |0..3.56..9:.<..?|
000000c0 c0 41 42 c3 44 c5 c6 47 48 c9 ca 4b cc 4d 4e cf |.AB.D..GH..K.MN.|
000000d0 50 d1 d2 53 d4 55 56 d7 d8 59 5a db 5c dd de 5f |P..S.UV..YZ.\.._|
000000e0 60 e1 e2 63 e4 65 66 e7 e8 69 6a eb 6c ed ee 6f |`..c.ef..ij.l..o|
000000f0 f0 71 72 f3 74 f5 f6 77 78 f9 fa 7b fc 7d 7e ff |.qr.t..wx..{.}~.|
00000100

18
bin/dd/ref.parnone Normal file
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@ -0,0 +1,18 @@
$FreeBSD$
00000000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f |................|
00000010 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f |................|
00000020 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f | !"#$%&'()*+,-./|
00000030 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f |0123456789:;<=>?|
00000040 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f |@ABCDEFGHIJKLMNO|
00000050 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f |PQRSTUVWXYZ[\]^_|
00000060 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f |`abcdefghijklmno|
00000070 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f |pqrstuvwxyz{|}~.|
00000080 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f |................|
00000090 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f |................|
000000a0 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f | !"#$%&'()*+,-./|
000000b0 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f |0123456789:;<=>?|
000000c0 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f |@ABCDEFGHIJKLMNO|
000000d0 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f |PQRSTUVWXYZ[\]^_|
000000e0 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f |`abcdefghijklmno|
000000f0 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f |pqrstuvwxyz{|}~.|
00000100

18
bin/dd/ref.parodd Normal file
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@ -0,0 +1,18 @@
$FreeBSD$
00000000 80 01 02 83 04 85 86 07 08 89 8a 0b 8c 0d 0e 8f |................|
00000010 10 91 92 13 94 15 16 97 98 19 1a 9b 1c 9d 9e 1f |................|
00000020 20 a1 a2 23 a4 25 26 a7 a8 29 2a ab 2c ad ae 2f | ..#.%&..)*.,../|
00000030 b0 31 32 b3 34 b5 b6 37 38 b9 ba 3b bc 3d 3e bf |.12.4..78..;.=>.|
00000040 40 c1 c2 43 c4 45 46 c7 c8 49 4a cb 4c cd ce 4f |@..C.EF..IJ.L..O|
00000050 d0 51 52 d3 54 d5 d6 57 58 d9 da 5b dc 5d 5e df |.QR.T..WX..[.]^.|
00000060 e0 61 62 e3 64 e5 e6 67 68 e9 ea 6b ec 6d 6e ef |.ab.d..gh..k.mn.|
00000070 70 f1 f2 73 f4 75 76 f7 f8 79 7a fb 7c fd fe 7f |p..s.uv..yz.|...|
00000080 80 01 02 83 04 85 86 07 08 89 8a 0b 8c 0d 0e 8f |................|
00000090 10 91 92 13 94 15 16 97 98 19 1a 9b 1c 9d 9e 1f |................|
000000a0 20 a1 a2 23 a4 25 26 a7 a8 29 2a ab 2c ad ae 2f | ..#.%&..)*.,../|
000000b0 b0 31 32 b3 34 b5 b6 37 38 b9 ba 3b bc 3d 3e bf |.12.4..78..;.=>.|
000000c0 40 c1 c2 43 c4 45 46 c7 c8 49 4a cb 4c cd ce 4f |@..C.EF..IJ.L..O|
000000d0 d0 51 52 d3 54 d5 d6 57 58 d9 da 5b dc 5d 5e df |.QR.T..WX..[.]^.|
000000e0 e0 61 62 e3 64 e5 e6 67 68 e9 ea 6b ec 6d 6e ef |.ab.d..gh..k.mn.|
000000f0 70 f1 f2 73 f4 75 76 f7 f8 79 7a fb 7c fd fe 7f |p..s.uv..yz.|...|
00000100

18
bin/dd/ref.parset Normal file
View File

@ -0,0 +1,18 @@
$FreeBSD$
00000000 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f |................|
00000010 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f |................|
00000020 a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af |................|
00000030 b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf |................|
00000040 c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf |................|
00000050 d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df |................|
00000060 e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef |................|
00000070 f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff |................|
00000080 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f |................|
00000090 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f |................|
000000a0 a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af |................|
000000b0 b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf |................|
000000c0 c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf |................|
000000d0 d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df |................|
000000e0 e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef |................|
000000f0 f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff |................|
00000100