Re: Question about Ctrl-C and less

From: "Sean Utt" <sean(at)strateja(dot)com>
To: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Question about Ctrl-C and less
Date: 2005-10-22 21:48:53
Message-ID: 012401c5d752$6512fb00$0201a8c0@randomnoise
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> It won't work properly that way. SIGINT gets sent to all the members
> of the process group, not just the child. Psql isn't responsible for
> sending ctrl-c through to the child.

Except that if I am in less, and I do CONTROL-C, it doesn't do anything at
all.

It doesn't exit.

If I send a kill -2 to the process, it doesn't exit. less ignores SIGINT
completely.

So, whether or not they are working together in cooperation, the result we
have been seeing when typing CONTROL-C is completely under the control of
psql.

I do realize that the problem is one of when and how to cancel the query if
CONTROL-C is pressed.
If the query is still building and the output hasn't, or won't be, sent to
the pager, cancel the query.
If we are in the pager, don't respond to CONTROL-C, and instead output a
helpful hint telling people to use q to quit, which will do what they really
wanted anyway.
In theory, we already deal gracefully with q being pressed in the pager.

Sean

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