standards/165155: [PATCH][bin][standards] xargs does not print diagnostic information on utility termination via signal, or utility exit 255

[Matthew Story]

>Number:         165155
>Category:       standards
>Synopsis:       [PATCH][bin][standards] xargs does not print diagnostic information on utility termination via signal, or utility exit 255
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-standards
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Feb 14 22:10:05 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Matthew Story
>Release:        9.0
>Organization:
>Environment:
FreeBSD matt9fromouterspace 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan  3 07:15:25 UTC 2012     root at obrian.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
Per POSIX (IEEE Std 1003.1-2008):

If a command line meeting the specified requirements cannot be assembled, the utility cannot be invoked, an invocation of the utility is terminated by a signal, or an invocation of the utility exits with exit status 255, the xargs utility shall write a diagnostic message and exit without processing any remaining input.
(via: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/xargs.html)

FreeBSD xargs does exit without processing any remaining input if an invocation of utility terminates as a result of a signal, or if an invocation of utility exits with exit status 255, but it does not write a diagnostic message as required by the spec.
>How-To-Repeat:
$ jot - 1 10 | xargs -n1 sh -c 'kill $$'
$ # note no output
$ jot - 1 10 | xargs -n1 sh -c 'exit 255;'
$ # note no output
>Fix:
apply patch, result is:

$ jot - 1 10 | xargs -n1 sh -c 'kill $$'
xargs: sh: terminated with signal 15, aborting
$ jot - 1 10 | xargs -n1 sh -c 'exit 255'
xargs: sh: exited with status 255, aborting



Patch attached with submission follows:

diff -u a/usr.bin/xargs/xargs.c b/usr.bin/xargs/xargs.c
--- a/usr.bin/xargs/xargs.c	2012-01-02 22:23:44.000000000 -0500
+++ b/usr.bin/xargs/xargs.c	2012-02-14 16:39:20.000000000 -0500
@@ -608,8 +608,11 @@
 		 * If utility signaled or exited with a value of 255,
 		 * exit 1-125.
 		 */
-		if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255)
-			exit(1);
+		if (WIFSIGNALED(status))
+			errx(1, "%s: terminated with signal %d, aborting",
+				name, WTERMSIG(status));
+		if (WEXITSTATUS(status) == 255)
+			errx(1, "%s: exited with status 255, aborting", name);
 		if (WEXITSTATUS(status))
 			rval = 1;
 	}


>Release-Note:
>Audit-Trail:
>Unformatted: