[Toybox] FreeBSD porting, removing bashisms

[Ed Maste]

On 29 March 2016 at 23:54, Rob Landley <rob at landley.net> wrote:
>
> There are also a number of places where we know what the Linux
> information is, and use that. For example, in ifconfig:
>
>       // Is this an SIOCSI entry?
>       if ((off|0xff) == 0x89ff) {

Yes, I suspect tools like ifconfig and ps would need completely
separate implementations for non-Linux systems, but I believe many of
the will have no portability troubles. At first I'd be happy to just
avoid building the Linux-specific ones.

> Why is expecting /usr/bin/env to be at a specific absolute path less
> constraining than expecting bash to be at a specific absolute path?
>
> I've never understood that one...

Because /usr/bin/env is universally available on relevant UNIX-like
systems (POSIX requires it), and /bin/bash is not.

>> 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, but it hasn't been adopted widely elsewhere
as I thought (OS X has it though). It examines not more than the given
number of characters in the search string.

basename_r is:
/usr/include/libgen.h:char      *basename_r(const char *, char *);
Where a buffer is passed in to store the result. I see bionic
implements a similar basename_r but they sensibly pass a size_t for
the buffer length as well; FreeBSD just requires that the provided
buffer is at least MAXPATHLEN bytes.

> That said, we have lib/portability.c and lib/portability.h to paper over
> that sort of issue.

Thanks, I'll see what's being done for other systems already.

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