3 ecp \- fast copy, handling errors
33 disk sectors of the specified
39 copies multiple sectors (a `block') at a time for speed.
42 encounters an I/O error,
43 it transfers the current block again,
44 assuming the file is seekable,
46 prints the sector number(s) of the error(s),
47 and continues copying.
55 this was used mainly when reading a pipe on standard input
59 sets the block size (16,384 bytes by default) to
63 ask for confirmation on
65 before starting the copy.
68 sets a maximum number of consecutive I/O errors to permit
69 at the beginning of the copy before quitting to
71 Lots of consecutive errors may indicate a deeper problem,
72 such as missing media.
73 By default there is no limit.
78 (assuming zero-origin)
79 before beginning input.
84 (assuming zero-origin)
85 before beginning output.
88 print reassuring progress reports;
89 helpful mainly when dealing with cranky hardware.
92 copy sector groups in reverse order,
93 assuming the files are seekable;
94 this is most useful when
101 sets the sector size (512 bytes by default) to
105 verify the copy by rereading the
109 files after copying all sectors.
110 This is intended to force the disk to deliver the actual
111 data written on it rather than some cached copy.
112 The locations of any differences are printed.
115 `Swizzle' the input: stir the bits around in some fashion.
116 Intended for diagnosing bad disks by copying a disk to itself
117 a few times with swizzling on (to defeat caching in operating systems
118 or disk controllers).
130 and error retries only work on devices capable of seeking.
132 The set of options reflects decades of experience
133 dealing with troublesome hardware.
135 If the input file is a tape and
136 the last record on the tape before a file mark is less than
141 will read through past the file mark and into the next file.