Re: killed by signal

[Atom Smasher <atom@xxxxxxxxxxx>]

On Tue, 7 Apr 2009, Atom Smasher wrote:

> but if a command is suspended (TSTP; 20 on linux, 18 on freebsd) precmd 
> will see a return status <128, which could be a "legal" value for a 
> command to return indicating a particular failure. i'd like precmd to 
> distinguish between a command that returns 18 or 20 (freebsd or linux, 
> respectively), and a command that is suspended with ^Z.
>
> specific example... on freebsd i can get a return status of 18 either by 
> suspending a job with ^Z, or running:
> 	zip -MM foo.zip no-such-file
>  so the question is: how can the shell (can the shell?) tell that one of 
> those was suspended with a signal (^Z, TSTP), and zip which is 
> indicating a specific failure (zip: "File not found").
=========================

here's a hack.... after a command is suspended, $? is updated but 
$pipestatus isn't. so if
	[[ ${?} != ${${=pipestatus}[-1]} ]]
 then the preceding command must have been suspended.

but it doesn't work all the time: if a command returns with an exit status 
equal to a suspend signal (which is probably rare), and the next command 
is suspended with that signal, that would result in a false negative; 
failing to detect that a command was suspended... but most of the time it 
should work, and i don't think it's possible to get a false positive.

if anyone has a better way to do it...


--
        ...atom

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