On Mon, 29 Mar 2004 21:44:26 +1200, you wrote: >On Mon, 29 Mar 2004 21:00, Jim Cheetham wrote: >> On Mar 29, 2004, at 8:50 PM, Christopher Sawtell wrote: >> > Put both disks in the same machine and use cpio to move the data. >> > >> > man cpio >> > cpio --help >> >> cpio is a dreadful holdover from sys V unix, iirc ... the syntax is >> horrible, and there are absolutely no benefits over tar (not least >> originally because each Unix vendor used a different internal cpio >> format ...). > >The big advantage of cpio over tar is that the names of the files to be placed >in the archive are input to cpio's stdin. You can therefore use whatever file >selection algorithm is appropriate for the task at hand. In contrast, afaik, >tar can only copy directory trees. tar can take a file of filenames, which can be generated in any way you like ( -T ) > >cpio also can cope with endianism and half-word re-ordering. cpio therefore >makes an ideal transport method to move data between machines of different >architectures. Haven't come across problems like this since I used VMS in the '80s. IIRC it didn't work properly then, and I had to write a specific program to sort it out. > >The archive stream created by cpio comes out of its stdout. Thus it can be >used conveniently as the input to a pipe. So can tar ( -f - ) > >Whilst the traditional cpio implementations did indeed have a somewhat baroque >option and flag structure, the modern GNU implementation uses --long options >and is not only really quite understandable but also comprehensive. tar also has built in compression algorithms ( -j and -z ) which, although simple enough to add on the command line to cpio, the number of pipes you are using to perform a single task become rather daunting! > >> If the disks are on the same machine (which is doubtful because one of >> the machines is a laptop) then dd would be interesting (vide an earlier >> discussion on the list), or tar would be normal. > >Unless I'm totally mistaken, there is no mention of one of the machines being >a lappie in the original posting. ...vide an earlier discussion on the _list_ ?
In the early 80s DEC had an editor called teco. It was so powerful, and had such a 'baroque' options list, the challenge was to see if you could crash the system by typing in your name. cpio is a bit like that - not as bad, obviously, but I know what cpio -ivcBmudlk < infile.cpio does ( and there are some OS specific flags in there as well ), but it's not really user friendly, is it (: And don't forget, you don't need the leading '-' with tar options either. Consistency, who needs it! Steve
