Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site utcs.UUCP Path: utzoo!utcs!ian From: ian@utcs.UUCP (Ian F. Darwin) Newsgroups: net.bugs.4bsd Subject: dd(1) argument mangling (fix by documenting) Message-ID: <249@utcs.UUCP> Date: Wed, 5-Dec-84 15:57:48 EST Article-I.D.: utcs.249 Posted: Wed Dec 5 15:57:48 1984 Date-Received: Wed, 5-Dec-84 16:24:43 EST Organization: University of Toronto - General Purpose UNIX Lines: 42 Index: bin/dd.c 4.2BSD Description: The man page for dd(1) is nebulous about which CONV= parameters can be combined. Perhaps this is an attempt at emulating the etymological origins of the command name, but the humor is lost after you waste many hours rewriting tapes. Repeat-By: dd if=foo/bar of=/dev/rmt1 conv=ibm,block cat /dev/rmt1 You will see that the file on tape is in ASCII, indicating that the `block' option has caused the `ibm' option to be silently ignored. Fix: While `block' is new in 4.?BSD, some vagueness is present in V7, System V et. al, although it is unlikely to cause serious confusion except in 4.?BSD. To fix it, add the following paragraph to BUGS in the manual page: .PP Certain combinations of arguments to .I conv= are permitted. However, the .I block or .I unblock option cannot be combined with .IR ascii , .IR ebcdic "" or .IR ibm . Invalid combinations .I "silently ignore" all but the last mutually-exclusive keyword. -- Ian Darwin, Toronto {ihnp4|decvax}!utcs!ian