From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 04 May 2005 08:26:25 GMT
Subject: Re: How to get bash to shut up about SIGPIPE?
Message-ID: <E1DTFD7-00063T-00@gondolin.me.apana.org.au>
In-Reply-To: <Pine.LNX.4.58.0505031947530.26698@ppc970.osdl.org>

Linus Torvalds <torvalds@osdl.org> wrote:
> 
> But putting the traps _inside_ the loops seems to help. So something like 
> the appended at least makes it somewhat useful

It's not the loop that's important, but the subshell where the
signal is caught.  Every time you enter a subshell all traps are
reset.  Since anything that comes (before or) after a pipe symbol
goes into a subshell...

> Index: cg-log
> ===================================================================
> --- aa6233be6d1b8bf42797c409a7c23b50593afc99/cg-log  (mode:100755 sha1:aa2abf370753117a350818dbc91991b14d30ec6b)
> +++ uncommitted/cg-log  (mode:100755)
> @@ -47,10 +47,12 @@
> fi
> 
> $revls | $revsort | while read time commit parents; do
> +       trap "exit 1" SIGPIPE
>        [ "$revfmt" = "git-rev-list" ] && commit="$time"
>        echo $colheader""commit ${commit%:*} $coldefault;
>        git-cat-file commit $commit | \
>                while read key rest; do
> +                       trap "exit 1" SIGPIPE
>                        case "$key" in
>                        "author"|"committer")
>                                if [ "$key" = "author" ]; then

You need it in both places because the signal may be received
in either place, depending on whether it's the echo or something
inside the loop that dies while writing output.

Cheers,
-- 
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Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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