Re: sed --posix does not catch incomplete arguments

[Ralf Wildenhues]

Hello,

* Paolo Bonzini wrote on Mon, Jul 05, 2010 at 12:18:24PM CEST:
> On Sun, Jul 4, 2010 at 18:36, Bruno Haible <address@hidden> wrote:
> > So, I'm asking: Can GNU 'sed' be changed so that in --posix mode it rejects
> > either all incomplete fragments, or at least those that currently represent
> > a real portability problem (namely, those which end in a backslash)? [1][2]
> 
> The latter can be done.

Create a file F containing the two characters a\ without a final newline.
If I understand Posix correctly, then the following things should fail:

echo a | sed --posix -f F
echo a | sed --posix 'a\'
echo a | sed --posix 'c\'
echo a | sed --posix 'i\'
echo a | sed --posix -e 'a\' -e x
echo a | sed --posix -e 'c\' -e x
echo a | sed --posix -e 'i\' -e x

And removing --posix, the respective commands should pass, no matter
what the setting of POSIXLY_CORRECT.

Further, the following should still pass:

echo a | sed --posix -e \{ -e \}
echo a | sed --posix -e 't x' -e :x

The attached patch implements this behavior.

Posix also specifies that the text after a c i commands as having one or
more lines.  The patch does not enforce this.  Since the sed script need
not have a final newline, I guess that requirement means that there is a
newline after the 'a\', which then really means the above requirement.

Cheers,
Ralf

patch
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