bug#6308: Preserve command exit code in timeout(3)

[Thomas Krennwallner]

Dear Jim, dear Pádraig,

preserving the command's exit code is useful for, e.g., running solver
competitions, where competition participants have an upper bound on the
runtime for finding solutions to very hard problems.

Imagine you want to run a command which is outputting (periodically or
on-request) solutions to optimization problems, where better and better
solutions will be printed over time, until the final solution is
obtained.

Now if the process gets interrupted by timeout's signal, the command
will return with an exit code different from the one that means "final
solution found".  If there was already an "interesting" solution found,
a particular exit code would be returned, and if no solution has been
found until the signal was received would result in yet another exit
code.

This way, one would easily obtain the status of the solution without
parsing the output.  For exit code 124 one would only know that there
was a timeout, but not if the computation has already revealed
"interesting" results.

I'm thus very interested into seeing timeout --exit-status.

Best,
TK

-- 
Thomas Krennwallner
University assistant
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TU Wien - Vienna University of Technology
Institute of Information Systems
Favoritenstrasse 9-11, 1040 Wien, Austria
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T: +43 1 58801 18469   F: +43 1 58801 918469
tkren AT kr DOT tuwien DOT ac DOT at
http://www.kr.tuwien.ac.at/staff/tkren/
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DVR: 0005886