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 #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) {