A NOTE has been added to this issue. ====================================================================== http://austingroupbugs.net/view.php?id=1161 ====================================================================== Reported By: steffen Assigned To: ====================================================================== Project: 1003.1(2016)/Issue7+TC2 Issue ID: 1161 Category: Shell and Utilities Type: Clarification Requested Severity: Editorial Priority: normal Status: New Name: steffen Organization: User Reference: Section: command Page Number: 2596 Line Number: 84274 ff. Interp Status: --- Final Accepted Text: ====================================================================== Date Submitted: 2017-09-04 13:09 UTC Last Modified: 2017-09-07 17:58 UTC ====================================================================== Summary: command -v must find something executable ======================================================================
---------------------------------------------------------------------- (0003849) kre (reporter) - 2017-09-07 17:58 http://austingroupbugs.net/view.php?id=1161#c3849 ---------------------------------------------------------------------- Before we attempt to settle upon what the wording for "command -v" should be, can we go back to discovering its purpose? Why it exists at all, and what it is intended to be used for (and for this, whether we call it command -v, or which, or whence, or ... doesn't really matter.) What is the use case for this functionality, and what must I be able to conclude when the answer appears about that answer for that use case to be met? I remain unconvinced that there is a use case for which the requirements can be met (reliably, which implies that "usually" in the "I know from the answer that ..." is not acceptable) which does not involve actually attempting an exec() sys call on the intended answer and verifying that the exec works (at least as far as the sys call not failing, whatever happens after that) and if that is to be required, we would need a way to make that safe, which it currently is not. If more is needed than just that the exec() sys call will not fail, then we have even bigger problems. If the requirement is simply that "command -v name" finds the first $PATH[n]/name (where $PATH[n] has the obvious interpretation - not suggesting that that is, or should be, sh syntax) which has the 'x' bit set, then first I am unconvinced that is actually useful for anything much, but for what uses it might have, it has has already been shown in earlier notes, is not difficult to achieve using existing functionality - we do not need "command -v" for that. Perhaps the proper solution here is simply to remove "command -v" from the standard (implementations could continue to handle it, for backwards compat, but users would not, as they cannot today, expect any particular portable answer.) Issue History Date Modified Username Field Change ====================================================================== 2017-09-04 13:09 steffen New Issue 2017-09-04 13:09 steffen Name => steffen 2017-09-04 13:09 steffen Section => command 2017-09-04 13:09 steffen Page Number => 2596 2017-09-04 13:09 steffen Line Number => 84274 ff. 2017-09-04 15:49 kre Note Added: 0003821 2017-09-05 06:58 stephane Note Added: 0003823 2017-09-05 08:30 stephane Note Added: 0003824 2017-09-05 12:34 steffen Note Added: 0003825 2017-09-05 12:39 steffen Note Added: 0003826 2017-09-05 12:47 kre Note Added: 0003827 2017-09-05 13:37 steffen Note Added: 0003828 2017-09-05 15:37 chet_ramey Note Added: 0003829 2017-09-05 15:41 stephane Note Added: 0003830 2017-09-05 16:01 stephane Note Added: 0003831 2017-09-05 16:36 stephane Note Added: 0003832 2017-09-05 17:30 stephane Note Added: 0003833 2017-09-05 20:17 steffen Note Added: 0003834 2017-09-05 20:19 steffen Note Added: 0003835 2017-09-05 20:27 kre Note Added: 0003836 2017-09-05 20:29 chet_ramey Note Added: 0003837 2017-09-05 21:27 eblake Note Added: 0003838 2017-09-05 21:50 kre Note Added: 0003839 2017-09-05 21:52 kre Note Edited: 0003839 2017-09-05 22:21 eblake Note Added: 0003840 2017-09-05 22:23 Don Cragun Note Added: 0003841 2017-09-05 22:24 Don Cragun Note Deleted: 0003841 2017-09-06 00:00 kre Note Added: 0003842 2017-09-06 00:00 kre Note Deleted: 0003839 2017-09-06 08:30 stephane Note Added: 0003843 2017-09-06 08:32 stephane Note Edited: 0003843 2017-09-06 09:30 stephane Note Added: 0003844 2017-09-06 09:37 stephane Note Added: 0003845 2017-09-06 09:50 joerg Note Added: 0003846 2017-09-06 09:50 joerg Note Edited: 0003846 2017-09-06 09:50 joerg Note Edited: 0003846 2017-09-06 09:54 stephane Note Edited: 0003845 2017-09-06 12:55 steffen Note Added: 0003847 2017-09-06 13:41 stephane Note Added: 0003848 2017-09-07 17:31 kre Note Deleted: 0003842 2017-09-07 17:58 kre Note Added: 0003849 ======================================================================
