A NOTE has been added to this issue. ====================================================================== https://www.austingroupbugs.net/view.php?id=1913 ====================================================================== Reported By: calestyo Assigned To: ====================================================================== Project: 1003.1(2024)/Issue8 Issue ID: 1913 Category: Shell and Utilities Tags: tc1-2024 Type: Enhancement Request Severity: Editorial Priority: normal Status: Interpretation Required Name: Christoph Anton Mitterer Organization: User Reference: Shell & Utilities Section: 2.7.5, 2.7.6 Page Number: 2497 Line Number: 81097-81118 Interp Status: Proposed Final Accepted Text: https://www.austingroupbugs.net/view.php?id=1913#c7277 Resolution: Accepted As Marked Fixed in Version: ====================================================================== Date Submitted: 2025-03-12 03:33 UTC Last Modified: 2025-10-30 15:23 UTC ====================================================================== Summary: clarify/define the meaning of n<&n and m>&m redirections ======================================================================
---------------------------------------------------------------------- (0007299) geoffclare (manager) - 2025-10-30 15:23 https://www.austingroupbugs.net/view.php?id=1913#c7299 ---------------------------------------------------------------------- > If word evaluates to the same open file descriptor as n (or 0 or 1, respectively, if n is not specified), [...] That works, thanks for the suggestion. > I'd be concerned about changing the requirements on closing fds. At the moment there is only some non-normative text about this in C.2.7: <blockquote>Applications should not use the [n]<&- or [n]>&- operators to execute a utility or application with file descriptor 0 not open for reading or with file descriptor 1 or 2 not open for writing, as this might cause the executed program (or shell built-in) to misbehave.</blockquote> I think there ought to be some normative text to back this up. > sh -c 'exec 3<&0; exec <&-; exec <&3' should be fine (it's sensible and works in existing shells). I disagree that it's sensible. The "exec <&-" does not achieve anything useful and can just be omitted. Although, having said that, I would not object to an exception for "an exec command that reopens the closed file descriptor" in my proposed normative addition. Issue History Date Modified Username Field Change ====================================================================== 2025-03-12 03:33 calestyo New Issue 2025-03-12 07:00 larryv Note Added: 0007111 2025-03-13 02:41 calestyo Note Added: 0007112 2025-03-13 16:12 geoffclare Note Added: 0007115 2025-03-13 17:48 calestyo Note Added: 0007117 2025-03-13 20:20 larryv Note Added: 0007119 2025-03-13 20:43 larryv Note Added: 0007120 2025-03-14 09:44 geoffclare Note Edited: 0007115 2025-03-18 12:30 geoffclare Note Added: 0007125 2025-03-20 14:49 geoffclare Note Edited: 0007115 2025-09-25 11:34 geoffclare Note Added: 0007277 2025-10-23 15:34 geoffclare Note Edited: 0007277 2025-10-23 15:36 geoffclare Note Edited: 0007277 2025-10-23 15:37 geoffclare Status New => Interpretation Required 2025-10-23 15:37 geoffclare Resolution Open => Accepted As Marked 2025-10-23 15:37 geoffclare Interp Status => Pending 2025-10-23 15:37 geoffclare Final Accepted Text => https://www.austingroupbugs.net/view.php?id=1913#c7277 2025-10-23 15:38 geoffclare Tag Attached: tc1-2024 2025-10-23 15:52 ajosey Interp Status Pending => Proposed 2025-10-23 15:52 ajosey Note Added: 0007289 2025-10-23 16:46 hvd Note Added: 0007291 2025-10-23 21:17 stephane Note Added: 0007292 2025-10-23 21:24 stephane Note Added: 0007293 2025-10-25 18:47 hvd Note Added: 0007294 2025-10-28 11:59 geoffclare Note Added: 0007295 2025-10-28 12:35 hvd Note Added: 0007296 2025-10-28 15:52 geoffclare Note Added: 0007297 2025-10-28 16:30 hvd Note Added: 0007298 2025-10-30 15:23 geoffclare Note Added: 0007299 ======================================================================
