The following issue has been SUBMITTED.
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https://austingroupbugs.net/view.php?id=1600
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Reported By: geoffclare
Assigned To:
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Project: 1003.1(2016/18)/Issue7+TC2
Issue ID: 1600
Category: Rationale
Type: Error
Severity: Comment
Priority: normal
Status: New
Name: Geoff Clare
Organization: The Open Group
User Reference:
Section: C.1.7 Built-In Utilities
Page Number: 3716
Line Number: 127366
Interp Status: ---
Final Accepted Text:
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Date Submitted: 2022-08-23 09:28 UTC
Last Modified: 2022-08-23 09:28 UTC
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Summary: Problems with the suggested single-line shell
script: $0 "$@"
Description:
On the mailing list, Jakub Wilk reported a problem with the rationale in
C.1.7 that talks about implementing the 16 (sic) regular built-ins as a
single-line shell script:<pre>$0 "$@"</pre>
As he pointed out, "This wouldn't actually work: $0 is the absolute path,
so the script would recurse indefinitely."
Another problem is that these external utilities are supposed to be
exec-able using "the exec family of functions", which means all six
functions not just execlp() and execvp(), so the script needs a #! line
(and can only meet the requirements on systems that support #!).
Finally, the number 16 is out of date, as there are now 20 utilities in the
table in XCU 1.7.
Desired Action:
Change:<blockquote>However, it has been pointed out that all 16 utilities
in the table can be provided with 16 links to a single-line shell
script:<pre>$0 "$@" </pre></blockquote>to:<blockquote>However, it has been
pointed out that, on systems that support the (non-standard but ubiquitous)
"#!" mechanism to make scripts executable by the <i>exec</i> family of
functions, all of the utilities in the table can be provided as links to a
two-line shell script:<pre>#! /path/to/sh
${0##*/} "$@"</pre></blockquote>
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Issue History
Date Modified Username Field Change
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2022-08-23 09:28 geoffclare New Issue
2022-08-23 09:28 geoffclare Name => Geoff Clare
2022-08-23 09:28 geoffclare Organization => The Open Group
2022-08-23 09:28 geoffclare Section => C.1.7 Built-In
Utilities
2022-08-23 09:28 geoffclare Page Number => 3716
2022-08-23 09:28 geoffclare Line Number => 127366
2022-08-23 09:28 geoffclare Interp Status => ---
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