Re: Re: Handling of shell builtins in make(1)

From: Harti Brandt (hartmut.brandt_at_dlr.de)
Date: 05/24/05

  • Next message: Sergey Babkin: "Re: Re: Re: Handling of shell builtins in make(1)" 
    Date: Tue, 24 May 2005 14:19:17 +0200 (CEST)
To: Sergey Babkin <babkin@verizon.net>

    On Tue, 24 May 2005, Sergey Babkin wrote:

    SB>>From: Harti Brandt <hartmut.brandt@dlr.de>
    SB>
    SB>>On Mon, 23 May 2005, Scott Long wrote:
    SB>>
    SB>
    SB>>SL>> Opinions?
    SB>>SL>>
    SB>>SL>> harti
    SB>>SL>
    SB>>SL>4. Separate /bin/sh into a front end and back end (libsh) and include libsh
    SB>>SL>into make.
    SB>>SL>
    SB>>SL>(running and hiding as I hit the 'send' key)
    SB>>
    SB>>Would there be other uses for this?
    SB>
    SB>Yes, I think it could be useful for many programs.

    Hmm. What program is executing shell lines?

    SB>Or one more option: add a flag to shell that
    SB>will make it exit after any command returning non-0
    SB>status (at the ";" point, as opposed to "&&",
    SB>"||" and such). Then make could just pass all
    SB>the commands to the shell in one go. And it would

    There is the -e flag which does exactly this. Well, the description in the
    Posix page is a little bit convoluted, but basically it exits when a
    program whose exit status is not expclicitely tested exits with a non-zero
    status (this is not entirely correct, but almost).

    And currently we actually use sh -ec to execute commands. The problem with
    this is, that Posix wants sh -c. No -e! I think NetBSD has changed this
    (and there is a PR with a patch), but I'm somewhat reluctant to do it,
    because it may break things in unexpected ways. My current plan is to make
    the default -e normally and without -e in Posix mode.

    SB>be very useful for all kinds of sysadmin scripts
    SB>as well where explicitly checking for the results
    SB>of every command is a pain. Even with make it
    SB>would be a big improvement, since in the current
    SB>format a command failing inside a "for" loop
    SB>won't cause make to stop unless explicitly programmed
    SB>so, like:
    SB>
    SB>target: dependencies
    SB> for ... ;\
    SB> do \
    SB> cmd || exit 1; \
    SB> done

    This is the canonical way to write this. Our make, however doesn't need
    it.

    harti
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  • Next message: Sergey Babkin: "Re: Re: Re: Handling of shell builtins in make(1)"

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