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Jeremy Olexa wrote: |
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>> Please consider a new PROPERTIES=interactive setting that allows an |
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>> ebuild to indicate that it uses stdin and stdout for user |
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> |
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> I don't think anyone will disagree with this one. The one problem that I |
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> see is that if the ebuild still doesn't have this value in it, portage |
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> will *look* like it has hung itself out to dry. I have no idea if this |
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> is easy to fix or not. If it is easy, then I still would like to propose |
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> that it gets sent to the foreground when in background mode. |
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|
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We can use standard job control functions such as tcsetpgrp() to put |
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processes in the background and then detect when they're sent a |
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SIGTTIN signal in order to know that they've attempted to read from |
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stdin. |
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|
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However, it's still useful to have PROPERTIES=interactive as a means |
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have knowledge of this behavior in advance, in case the user would |
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like to mask such ebuilds. |
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|
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It also simplifies implementation details a bit if the package |
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manager can just grant exclusive stdio access in advance rather than |
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having to detect it when it happens and then having to update the |
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display from a saved output buffer or telling the application to |
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redraw itself (like dtach [1] does with Ctrl+L code) or whatnot. |
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|
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> What will |
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> portage's behavior be when the user asks to be in background mode and |
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> there is an ebuild in the depgraph that has PROPERTIES=interactive? |
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I was planning to add some option for masking those, like |
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- --exclude-property=interactive or something like that. That would |
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mask the package so that it wouldn't be be included in the depgraph |
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unless it happens to be installed already. |
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|
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> If |
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> it bails out, then the problem described above is moot (only if |
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> maintainers are diligent). |
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|
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Like Alec said, I don't think this is a difficult thing to get right |
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and even if the maintainer doesn't get it right initially then it's |
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not something that's very difficult to spot and fix. More elusive |
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bugs certainly do exist. That said, I still would like to make use |
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of the standard job control functions to detect and handle cases |
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like that. However, that does not entirely preclude the usefulness |
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of the knowledge that PROPERTIES=interactive is intended to provide. |
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|
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> -Jeremy |
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> |
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> |
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|
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[1] |
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http://www.opengroup.org/onlinepubs/009695399/functions/tcsetpgrp.html |
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[2] http://dtach.sourceforge.net/ |
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