Re: [gawk-stable] bug: fatal error when getline from directory

[Eric Blake]

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According to Paolo on 1/4/2009 4:30 PM:
> please define 'human-readable'.
> POSIX 'text file' is any sequence of chars except for '\0', in 1+ lines
> shorter than LINE_MAX, which is OS/implementation-specific.

And one more requirement - the file must end in a newline.  Ending in any
other byte makes the file non-text.

> So you may well
> have a 'text file' which isn't that 'human-readable' at all.

Yes, that is true.

> 
> *I* might agree that dirs aren't "text" nor "binary" files, yet you can 
> open(2)+read(2) a dir without a glitch - you get an EOF.

Not necessarily.  That is the behavior on some OS, but not all.  Some
platforms don't even allow open(2) on directories (think mingw), although
that violates POSIX; within the realm of POSIX, you also have the three
behaviors after the open(2) succeeds: the read(2) fails with EISDIR (think
Linux), it succeeds with 0 bytes (your report of EOF, think BSD), or it
succeeds with non-zero bytes (raw reading which can generally be overlaid
to a struct dirent; think BeOS or older Unix).

> But that's not the point.

Exactly.  The point is that the only portable choice that we can implement
and document across all platforms is to fail on attempts to read a
directory, even if the OS would otherwise allow it.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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