Re: Relocated Header Directories

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From	Kushal Kumaran <kushal@locationd.net>
Newsgroups	linux.debian.user
Subject	Re: Relocated Header Directories
Date	Mon, 21 Aug 2017 16:10:03 +0200
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Dutch Ingraham <stoa@gmx.us> writes:

> Hi everyone -
>
> It seems Debian has moved some header directories, like /usr/include/bits (and
> sys, and asm, etc.) from /usr/include/ to, e.g., /usr/include/i386-linux-gnu/bits/
> (arch-specific).
>
> My first question is:  Why?
>

This is so that headers that are architecture independent are separated
from headers with are architecture dependent.  Specifically, that they
are available at different paths.  This lets you install the headers
(and libraries) for different architectures simultaneously, which is
essential for debian's multiarch support.

> My second question is: How does this work?  There are no symlinks, yet a file
> like /usr/include/signal.h, has the standard "#include <bits/sigset.h>", yet
> that path does not exist with the change noted above.  So how is this file
> included?
>
> Any enlightenment is appreciated.

There are several directories configured for searching header files.
The command "gcc -xc -E -v - < /dev/null" will print those paths out.
For my system, the directories are:

 /usr/lib/gcc/x86_64-linux-gnu/6/include
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/6/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include

The list will be different for you because you appear to be running
i386.

-- 
regards,
kushal

Thread

Relocated Header Directories Dutch Ingraham <stoa@gmx.us> - 2017-08-21 15:40 +0200
  Re: Relocated Header Directories Kushal Kumaran <kushal@locationd.net> - 2017-08-21 16:10 +0200
    Re: Relocated Header Directories <tomas@tuxteam.de> - 2017-08-21 16:20 +0200
    Re: Relocated Header Directories Dutch Ingraham <stoa@gmx.us> - 2017-08-21 21:20 +0200
      Re: Relocated Header Directories <tomas@tuxteam.de> - 2017-08-21 22:00 +0200
        Re: Relocated Header Directories Dutch Ingraham <stoa@gmx.us> - 2017-08-21 22:10 +0200
      Re: Relocated Header Directories Christian Seiler <christian@iwakd.de> - 2017-08-22 07:10 +0200
        Re: Relocated Header Directories Mario Castelán Castro <marioxcc.MT@yandex.com> - 2017-08-22 16:50 +0200
          Re: Relocated Header Directories Christian Seiler <christian@iwakd.de> - 2017-08-22 17:00 +0200
            Re: Relocated Header Directories Mario Castelán Castro <marioxcc.MT@yandex.com> - 2017-08-22 17:00 +0200
  Re: Relocated Header Directories <tomas@tuxteam.de> - 2017-08-21 16:10 +0200
    Re: Relocated Header Directories Dutch Ingraham <stoa@gmx.us> - 2017-08-21 21:00 +0200

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