Bug#34380: glibc-doc: info libc says open has O_SHLOCK, yet I cannot find it in /usr/include

[Zack Weinberg <zack@rabi.columbia.edu>]

>From libc.info:
> - Macro: int O_SHLOCK
>     Acquire a shared lock on the file, as with `flock'.  *Note File
>     Locks::.
>
>However, I cannot find O_SHLOCK in any include file. Looks like a 
>documentation bug (documenting a nonimplemented/misimplemented feature).

Look more closely and you'll see it's documented as a BSD extension.
Linux happens not to implement it.  This was reported last week to
upstream, and we've clarified the docs.

zw