[Toybox] FreeBSD porting, removing bashisms

[Ed Maste]

On 30 March 2016 at 05:21, Rob Landley <rob at landley.net> wrote:
> On 03/29/2016 07:37 PM, Ed Maste wrote:
>>
>> Because /usr/bin/env is universally available on relevant UNIX-like
>> systems (POSIX requires it), and /bin/bash is not.
>
> Posix requires "batch", "compress", and "pax" too, none of which are
> currently on my system. (There's a lot of other stuff in the standard it
> expects ala qdel, sccs, ed, fort77, uucp. And stuff like cpio and cc
> that the standard _dropped_ but which linux requires. And then show me
> the posix spec for "init" or "mount"...)
>
> But ok, let's assume it does expect it there. Where does it say it
> should be in /usr/bin instead of in /bin? Why is expecting THAT to be at
> a specific location ok, but not expecting bash to be at a specific
> location (next to /bin/sh) to avoid having to launch two binaries to
> interpret one file?

Perhaps I should have left the parenthetical comment out -- I just
meant POSIX requires 'env'. The more relevant point is that Linuxes,
*BSD, OS X, Solaris, Illumos and derivatives all have /usr/bin/env.

>>>> Another error shows up in a few spots due to conflicts between a
>>>> couple of toybox functions and libc:
>>>>
>>>> ./lib/lib.h:204:7: error: conflicting types for 'strnstr'
>>>> char *strnstr(char *line, char *str);
>>>> ./lib/lib.h:289:7: error: conflicting types for 'basename_r'
>>>> char *basename_r(char *name);
>>>
>>> In neither case did you say what the conflicting definition was. What
>>> header they came from, how they're defining those prototypes...
>>
>> strnstr is:
>> /usr/include/string.h:char      *strnstr(const char *, const char *,
>> size_t) __pure;
>> It originated in FreeBSD,
>
> I'd never heard of it, I just combined "strnchr" and "strstr" in the
> obvious way. Apparently what I'm missing is const, which toybox
> functions never have. (Some global read-only arrays have it, that's
> about it, one of the links in http://landley.net/toybox/cleanup.html
> explains why.)

The reference I found for strnchr claimed it's used to "Find a
character in a length limited string."

It looks like toybox's strnstr is what FreeBSD and glibc call
strcasestr: "The strcasestr() function is like strstr(), but ignores
the case of both arguments."

> Then again the WORST such name clash was way back when I wrote a BBS
> that had a DOS direct screen write function that updated the buffer at
> 0xb8000000 directly, using a function called "throw()". Switching from
> borland C++ 1.0 to borland C++ 2.0 made that program very unhappy...

Yeah, I can't imagine that went well.

The most annoying case of this for me is qsort_r, where BSDs and glibc
have implementations with arguments in a different order.

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