Rob Sullivan cleaned up the longstanding patch from Hideki IWAMOTO to add

ibs and obs support to dd, and made it configurable.  I cleaned it up a bit
further and moved conv= into the same config option.

coreutils/Config.in

@@ -127,6 +127,14 @@ config CONFIG_FEATURE_DD_SIGNAL_HANDLING
 	  $ dd if=/dev/zero of=/dev/null& pid=$! $ kill -USR1 $pid; sleep 1; kill $pid 
 	  10899206+0 records in 10899206+0 records out
 
+config CONFIG_FEATURE_DD_IBS_OBS
+	bool "Enable ibs, obs and conv options"
+	default n
+	depends on CONFIG_DD
+	help
+	  Enables support for writing a certain number of bytes in and out,
+	  at a time, and performing conversions on the data stream.
+
 config CONFIG_DF
 	bool "df"
 	default n

coreutils/dd.c

@@ -45,21 +45,13 @@ static void dd_output_status(int cur_signal)
 
 int dd_main(int argc, char **argv)
 {
-	size_t count = -1;
+	size_t count = -1, oc = 0, ibs = 512, obs = 512;
-	size_t bs = 512;
 	ssize_t n;
-	off_t seek = 0;
+	off_t seek = 0, skip = 0;
-	off_t skip = 0;
+	int sync_flag = FALSE, noerror = FALSE, trunc_flag = TRUE, twobufs_flag = 0,
-	int sync_flag = FALSE;
+		oflag, ifd, ofd, i;
-	int noerror = FALSE;
+	const char *infile = NULL, *outfile = NULL;
-	int trunc_flag = TRUE;
+	char *ibuf, *obuf;
-	int oflag;
-	int ifd;
-	int ofd;
-	int i;
-	const char *infile = NULL;
-	const char *outfile = NULL;
-	char *buf;
 
 	if (ENABLE_FEATURE_DD_SIGNAL_HANDLING)
 	{
@@ -73,43 +65,49 @@ int dd_main(int argc, char **argv)
 	}
 
 	for (i = 1; i < argc; i++) {
-		if (strncmp("bs=", argv[i], 3) == 0)
+		if (ENABLE_FEATURE_DD_IBS_OBS && !strncmp("ibs=", argv[i], 4)) {
-			bs = bb_xparse_number(argv[i]+3, dd_suffixes);
+			ibs = bb_xparse_number(argv[i]+4, dd_suffixes);
-		else if (strncmp("count=", argv[i], 6) == 0)
+			twobufs_flag++;
+		} else if (ENABLE_FEATURE_DD_IBS_OBS && !strncmp("obs=", argv[i], 4)) {
+			obs = bb_xparse_number(argv[i]+4, dd_suffixes);
+			twobufs_flag++;
+		} else if (!strncmp("bs=", argv[i], 3)) {
+			ibs = obs = bb_xparse_number(argv[i]+3, dd_suffixes);
+		} else if (!strncmp("count=", argv[i], 6))
 			count = bb_xparse_number(argv[i]+6, dd_suffixes);
-		else if (strncmp("seek=", argv[i], 5) == 0)
+		else if (!strncmp("seek=", argv[i], 5))
 			seek = bb_xparse_number(argv[i]+5, dd_suffixes);
-		else if (strncmp("skip=", argv[i], 5) == 0)
+		else if (!strncmp("skip=", argv[i], 5))
 			skip = bb_xparse_number(argv[i]+5, dd_suffixes);
-		else if (strncmp("if=", argv[i], 3) == 0)
+		else if (!strncmp("if=", argv[i], 3))
 			infile = argv[i]+3;
-		else if (strncmp("of=", argv[i], 3) == 0)
+		else if (!strncmp("of=", argv[i], 3))
 			outfile = argv[i]+3;
-		else if (strncmp("conv=", argv[i], 5) == 0) {
+		else if (ENABLE_FEATURE_DD_IBS_OBS && !strncmp("conv=", argv[i], 5)) {
-			buf = argv[i]+5;
+			ibuf = argv[i]+5;
 			while (1) {
-				if (strncmp("notrunc", buf, 7) == 0) {
+				if (!strncmp("notrunc", ibuf, 7)) {
 					trunc_flag = FALSE;
-					buf += 7;
+					ibuf += 7;
-				} else if (strncmp("sync", buf, 4) == 0) {
+				} else if (!strncmp("sync", ibuf, 4)) {
 					sync_flag = TRUE;
-					buf += 4;
+					ibuf += 4;
-				} else if (strncmp("noerror", buf, 7) == 0) {
+				} else if (!strncmp("noerror", ibuf, 7)) {
 					noerror = TRUE;
-					buf += 7;
+					ibuf += 7;
 				} else {
 					bb_error_msg_and_die("invalid conversion `%s'", argv[i]+5);
 				}
-				if (buf[0] == '\0')
+				if (ibuf[0] == '\0') break;
-					break;
+				if (ibuf[0] == ',') ibuf++;
-				if (buf[0] == ',')
-					buf++;
 			}
 		} else
 			bb_show_usage();
 	}
+	ibuf = xmalloc(ibs);
 
-	buf = xmalloc(bs);
+	if (twobufs_flag) obuf = xmalloc(obs);
+	else obuf = ibuf;
 
 	if (infile != NULL) {
 		ifd = bb_xopen(infile, O_RDONLY);
@@ -128,7 +126,7 @@ int dd_main(int argc, char **argv)
 		ofd = bb_xopen3(outfile, oflag, 0666);
 
 		if (seek && trunc_flag) {
-			if (ftruncate(ofd, seek * bs) < 0) {
+			if (ftruncate(ofd, seek * obs) < 0) {
 				struct stat st;
 
 				if (fstat (ofd, &st) < 0 || S_ISREG (st.st_mode) ||
@@ -143,13 +141,19 @@ int dd_main(int argc, char **argv)
 	}
 
 	if (skip) {
-		if (lseek(ifd, skip * bs, SEEK_CUR) < 0) {
+		if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
-			bb_perror_msg_and_die("%s", infile);
+			while (skip-- > 0) {
+				n = safe_read(ifd, ibuf, ibs);
+				if (n < 0)
+					bb_perror_msg_and_die("%s", infile);
+				if (n == 0)
+					break;
+			}
 		}
 	}
 
 	if (seek) {
-		if (lseek(ofd, seek * bs, SEEK_CUR) < 0) {
+		if (lseek(ofd, seek * obs, SEEK_CUR) < 0) {
 			bb_perror_msg_and_die("%s", outfile);
 		}
 	}
@@ -157,40 +161,63 @@ int dd_main(int argc, char **argv)
 	while (in_full + in_part != count) {
 		if (noerror) {
 			/* Pre-zero the buffer when doing the noerror thing */
-			memset(buf, '\0', bs);
+			memset(ibuf, '\0', ibs);
+		}
+
+		n = safe_read(ifd, ibuf, ibs);
+		if (n == 0) {
+			break;
 		}
-		n = safe_read(ifd, buf, bs);
 		if (n < 0) {
 			if (noerror) {
-				n = bs;
+				n = ibs;
 				bb_perror_msg("%s", infile);
 			} else {
 				bb_perror_msg_and_die("%s", infile);
 			}
 		}
-		if (n == 0) {
+		if ((size_t)n == ibs) {
-			break;
-		}
-		if ((size_t)n == bs) {
 			in_full++;
 		} else {
 			in_part++;
+			if (sync_flag) {
+				memset(ibuf + n, '\0', ibs - n);
+				n = ibs;
+			}
 		}
-		if (sync_flag) {
+		if (twobufs_flag) {
-			memset(buf + n, '\0', bs - n);
+			char *tmp = ibuf;
-			n = bs;
+			while (n) {
-		}
+				size_t d = obs - oc;
-		n = bb_full_write(ofd, buf, n);
+
-		if (n < 0) {
+				if (d > n) d = n;
-			bb_perror_msg_and_die("%s", outfile);
+				memcpy(obuf + oc, tmp, d);
-		}
+				n -= d;
-		if ((size_t)n == bs) {
+				tmp += d;
-			out_full++;
+				oc += d;
+				if (oc == obs) {
+					if (bb_full_write(ofd, obuf, obs) < 0) {
+						bb_perror_msg_and_die("%s", outfile);
+					}
+					out_full++;
+					oc = 0;
+				}
+			}
 		} else {
-			out_part++;
+			if ((n = bb_full_write(ofd, ibuf, n)) < 0) {
+				bb_perror_msg_and_die("%s", outfile);
+			}
+			if (n == ibs) out_full++;
+			else out_part++;
 		}
 	}
-
+	
+	if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
+		if (bb_full_write(ofd, obuf, oc) < 0) {
+			bb_perror_msg_and_die("%s", outfile);
+		}
+		out_part++;
+	}
 	if (close (ifd) < 0) {
 		bb_perror_msg_and_die("%s", infile);
 	}

include/usage.h

@@ -370,19 +370,23 @@ USE_FEATURE_DATE_ISOFMT( \
 	"64\n"
 
 #define dd_trivial_usage \
-	"[if=FILE] [of=FILE] [bs=N] [count=N] [skip=N]\n" \
+	"[if=FILE] [of=FILE] " USE_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n" \
-	"\t  [seek=N] [conv=notrunc|noerror|sync]"
+	"\t  [seek=N]" USE_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync]")
 #define dd_full_usage \
 	"Copy a file, converting and formatting according to options\n\n" \
 	"\tif=FILE\t\tread from FILE instead of stdin\n" \
 	"\tof=FILE\t\twrite to FILE instead of stdout\n" \
 	"\tbs=N\t\tread and write N bytes at a time\n" \
+	USE_FEATURE_DD_IBS_OBS("\tibs=N\t\tread N bytes at a time\n") \
+	USE_FEATURE_DD_IBS_OBS("\tobs=N\t\twrite N bytes at a time\n") \
 	"\tcount=N\t\tcopy only N input blocks\n" \
 	"\tskip=N\t\tskip N input blocks\n" \
 	"\tseek=N\t\tskip N output blocks\n" \
-	"\tconv=notrunc\tdon't truncate output file\n" \
+	USE_FEATURE_DD_IBS_OBS( \
-	"\tconv=noerror\tcontinue after read errors\n" \
+		"\tconv=notrunc\tdon't truncate output file\n" \
-	"\tconv=sync\tpad blocks with zeros\n" \
+		"\tconv=noerror\tcontinue after read errors\n" \
+		"\tconv=sync\tpad blocks with zeros\n" \
+	) \
 	"\n" \
 	"Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024),\n" \
 	"MD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)"

patches/dd_ibs_and_obs.diff

@@ -1,252 +0,0 @@
-This patch adds support of ibs= and obs= to dd.
-----
-Hideki IWAMOTO  h-iwamoto@kit.hi-ho.ne.jp
-
-
---- a/include/usage.h	29 Mar 2004 08:20:08 -0000	1.198
-+++ b/include/usage.h	4 Apr 2004 07:15:21 -0000
-@@ -309,13 +309,15 @@
- 	"64\n"
- 
- #define dd_trivial_usage \
--	"[if=FILE] [of=FILE] [bs=N] [count=N] [skip=N]\n" \
--	"\t  [seek=N] [conv=notrunc|noerror|sync]"
-+	"[if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N]\n" \
-+	"\t  [skip=N] [seek=N] [conv=notrunc|noerror|sync]"
- #define dd_full_usage \
- 	"Copy a file, converting and formatting according to options\n\n" \
- 	"\tif=FILE\t\tread from FILE instead of stdin\n" \
- 	"\tof=FILE\t\twrite to FILE instead of stdout\n" \
--	"\tbs=N\t\tread and write N bytes at a time\n" \
-+	"\tibs=N\t\tread N bytes at a time\n" \
-+	"\tobs=N\t\twrite N bytes at a time\n" \
-+	"\tbs=N\t\tforce ibs=N and obs=N\n" \
- 	"\tcount=N\t\tcopy only N input blocks\n" \
- 	"\tskip=N\t\tskip N input blocks\n" \
- 	"\tseek=N\t\tskip N output blocks\n" \
-@@ -323,6 +325,8 @@
- 	"\tconv=noerror\tcontinue after read errors\n" \
- 	"\tconv=sync\tpad blocks with zeros\n" \
- 	"\n" \
-+	"If the bs= expr operand is not specified, the input is processed and collected\n" \
-+	"into full-sized output blocks until the end of the input is reached.\n" \
- 	"Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024),\n" \
- 	"MD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)."
- #define dd_example_usage \
---- a/coreutils/dd.c	30 Jan 2004 22:24:32 -0000	1.55
-+++ b/coreutils/dd.c	4 Apr 2004 07:15:21 -0000
-@@ -30,6 +30,10 @@
- #include <fcntl.h>
- #include "busybox.h"
- 
-+#define C_NOERROR	0x0001
-+#define C_TRUNC		0x0002
-+#define C_SYNC		0x0004
-+#define C_TWOBUFS	0x0008
- 
- static const struct suffix_mult dd_suffixes[] = {
- 	{ "c", 1 },
-@@ -51,13 +55,13 @@
- 	size_t in_full = 0;
- 	size_t in_part = 0;
- 	size_t count = -1;
--	size_t bs = 512;
-+	size_t ibs = 512;
-+	size_t obs = 512;
-+	size_t oc = 0;
- 	ssize_t n;
- 	off_t seek = 0;
- 	off_t skip = 0;
--	int sync_flag = FALSE;
--	int noerror = FALSE;
--	int trunc_flag = TRUE;
-+	unsigned int dd_flags = C_TWOBUFS | C_TRUNC;
- 	int oflag;
- 	int ifd;
- 	int ofd;
-@@ -65,11 +69,18 @@
- 	const char *infile = NULL;
- 	const char *outfile = NULL;
- 	char *buf;
-+	char *ibuf;
-+	char *obuf;
- 
- 	for (i = 1; i < argc; i++) {
--		if (strncmp("bs=", argv[i], 3) == 0)
--			bs = bb_xparse_number(argv[i]+3, dd_suffixes);
--		else if (strncmp("count=", argv[i], 6) == 0)
-+		if (strncmp("ibs=", argv[i], 4) == 0)
-+			ibs = bb_xparse_number(argv[i]+4, dd_suffixes);
-+		else if (strncmp("obs=", argv[i], 4) == 0)
-+			obs = bb_xparse_number(argv[i]+4, dd_suffixes);
-+		else if (strncmp("bs=", argv[i], 3) == 0) {
-+			ibs = obs = bb_xparse_number(argv[i]+3, dd_suffixes);
-+			dd_flags &= ~C_TWOBUFS;
-+		} else if (strncmp("count=", argv[i], 6) == 0)
- 			count = bb_xparse_number(argv[i]+6, dd_suffixes);
- 		else if (strncmp("seek=", argv[i], 5) == 0)
- 			seek = bb_xparse_number(argv[i]+5, dd_suffixes);
-@@ -83,13 +94,13 @@
- 			buf = argv[i]+5;
- 			while (1) {
- 				if (strncmp("notrunc", buf, 7) == 0) {
--					trunc_flag = FALSE;
-+					dd_flags &= ~C_TRUNC;
- 					buf += 7;
- 				} else if (strncmp("sync", buf, 4) == 0) {
--					sync_flag = TRUE;
-+					dd_flags |= C_SYNC;
- 					buf += 4;
- 				} else if (strncmp("noerror", buf, 7) == 0) {
--					noerror = TRUE;
-+					dd_flags |= C_NOERROR;
- 					buf += 7;
- 				} else {
- 					bb_error_msg_and_die("invalid conversion `%s'", argv[i]+5);
-@@ -103,7 +114,12 @@
- 			bb_show_usage();
- 	}
- 
--	buf = xmalloc(bs);
-+	ibuf = xmalloc(ibs);
-+
-+	if (dd_flags & C_TWOBUFS)
-+		obuf = xmalloc(obs);
-+	else
-+		obuf = ibuf;
- 
- 	if (infile != NULL) {
- 		ifd = bb_xopen(infile, O_RDONLY);
-@@ -115,7 +131,7 @@
- 	if (outfile != NULL) {
- 		oflag = O_WRONLY | O_CREAT;
- 
--		if (!seek && trunc_flag) {
-+		if (!seek && (dd_flags & C_TRUNC)) {
- 			oflag |= O_TRUNC;
- 		}
- 
-@@ -123,8 +139,8 @@
- 			bb_perror_msg_and_die("%s", outfile);
- 		}
- 
--		if (seek && trunc_flag) {
--			if (ftruncate(ofd, seek * bs) < 0) {
-+		if (seek && (dd_flags & C_TRUNC)) {
-+			if (ftruncate(ofd, seek * obs) < 0) {
- 				struct stat st;
- 
- 				if (fstat (ofd, &st) < 0 || S_ISREG (st.st_mode) ||
-@@ -139,52 +155,88 @@
- 	}
- 
- 	if (skip) {
--		if (lseek(ifd, skip * bs, SEEK_CUR) < 0) {
--			bb_perror_msg_and_die("%s", infile);
-+		if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
-+			while (skip-- > 0) {
-+				n = safe_read(ifd, ibuf, ibs);
-+				if (n < 0)
-+					bb_perror_msg_and_die("%s", infile);
-+				if (n == 0)
-+					break;
-+			}
- 		}
- 	}
- 
- 	if (seek) {
--		if (lseek(ofd, seek * bs, SEEK_CUR) < 0) {
-+		if (lseek(ofd, seek * obs, SEEK_CUR) < 0) {
- 			bb_perror_msg_and_die("%s", outfile);
- 		}
- 	}
- 
- 	while (in_full + in_part != count) {
--		if (noerror) {
-+		if (dd_flags & C_NOERROR) {
- 			/* Pre-zero the buffer when doing the noerror thing */
--			memset(buf, '\0', bs);
-+			memset(ibuf, '\0', ibs);
-+		}
-+
-+		n = safe_read(ifd, ibuf, ibs);
-+		if (n == 0) {
-+			break;
- 		}
--		n = safe_read(ifd, buf, bs);
- 		if (n < 0) {
--			if (noerror) {
--				n = bs;
-+			if (dd_flags & C_NOERROR) {
-+				n = ibs;
- 				bb_perror_msg("%s", infile);
- 			} else {
- 				bb_perror_msg_and_die("%s", infile);
- 			}
- 		}
--		if (n == 0) {
--			break;
--		}
--		if (n == bs) {
-+		if (n == ibs) {
- 			in_full++;
- 		} else {
- 			in_part++;
-+			if (dd_flags & C_SYNC) {
-+				memset(ibuf + n, '\0', ibs - n);
-+				n = ibs;
-+			}
- 		}
--		if (sync_flag) {
--			memset(buf + n, '\0', bs - n);
--			n = bs;
-+
-+		if (dd_flags & C_TWOBUFS) {
-+			size_t d;
-+			char *tmp = ibuf;
-+
-+			while (n) {
-+				d = obs - oc;
-+				if (d > n)
-+					d = n;
-+				memcpy(obuf + oc, tmp, d);
-+				n -= d;
-+				tmp += d;
-+				oc += d;
-+				if (oc == obs) {
-+					if (bb_full_write(ofd, obuf, obs) < 0) {
-+						bb_perror_msg_and_die("%s", outfile);
-+					}
-+					out_full++;
-+					oc = 0;
-+				}
-+			}
-+		} else {
-+			if (bb_full_write(ofd, ibuf, n) < 0) {
-+				bb_perror_msg_and_die("%s", outfile);
-+			}
-+			if (n == ibs) {
-+				out_full++;
-+			} else {
-+				out_part++;
-+			}
- 		}
--		n = bb_full_write(ofd, buf, n);
--		if (n < 0) {
-+	}
-+
-+	if (oc) {
-+		if (bb_full_write(ofd, obuf, oc) < 0) {
- 			bb_perror_msg_and_die("%s", outfile);
- 		}
--		if (n == bs) {
--			out_full++;
--		} else {
--			out_part++;
--		}
-+		out_part++;
- 	}
- 
- 	if (close (ifd) < 0) {
-
-