Subject: iconv and errno
To: None <tech-userlevel@netbsd.org>
From: James K. Lowden <jklowden@schemamania.org>
List: tech-userlevel
Date: 04/24/2005 08:09:19
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Having recently installed NetBSD 2.0, I was happy to start using our
native iconv instead of GNU's.  I think the error messages it produces,
though, are misleading.  

I prepared a patch (my first ever).  

Problems as I see them:

1.	$ echo 'hi' | iconv -t asdf -f ucs-2le
	iconv: iconv_open(asdf, ucs-2le): No such file or directory

Should say that 'asdf' is not a valid encoding name.

2.	$ echo 'hi' | iconv -t ascii -f ucs-2le
	iconv: iconv(): Invalid argument

Should say that '\n' at byte 3 is an incorrect or incomplete sequence for
ucs-2le.  

3.	$ iconv -t ascii -f ucs-2le nosuchfile
	iconv: iconv: nosuchfile:No such file or directory

Why no space after the last colon?  And, anyway, why "iconv:" twice?  

Unfortunately, it seems only some of the trouble is in /usr/bin/iconv. 
Some if it stems from iconv(3).  

Remedies:

1.  /usr/src/lib/libc/iconv/iconv.c::_iconv_open calls _citrus_iconv_open,
which apparently returns ENOENT if the 'in' or 'out' arguments don't
exist.  The function sets errno, which iconv(1) duly reports to the poor
user as "No such file or directory".  That contradicts both the iconv(3)
man page and, IMHO, good sense.  It should set errno to EINVAL.  

2.  __iconv() returns EINVAL, which is good.  But when iconv(1) calls errx
with EINVAL, it produces the above message.  If it called errx with
EILSEQ, you'd see "iconv: iconv(): Illegal byte sequence", which at least
points the user at the data, instead of the command-line arguments.  

3.  Easy enough, even for me, unless there's some policy I should know
about?  

Patch:

The attached patch exhibits the right behavior, but includes a hack to
workaround the iconv_open(3) problem.  Is it good enough to send-pr?  

--jkl







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