Thanks for the clarifcation. So can I assume that the earlier behaviour was
somehow unintended
and the current behaviour is the right one. i.e the syntax error thrown is
valid.
The reason I'm asking is there are some old scripts with this syntax which
used to work in ksh2011,
so if this is not a bug, I guess I'll need to fix those scripts rather than
waiting for ksh to be fixed.
On Tue, May 19, 2015 at 9:35 PM, Terrence J. Doyle <
terrence.j.doyle+...@gmail.com> wrote:
>
> Actually, I'm surprised this ever worked. The quotes on line 5 of
> your
> script should be escaped, like this:
>
> FS = \"[()]\"
>
> Without the escapes ksh matches the double-quote after A= with the first
> one on line 5. So, the characters, [()], are unquoted (in both ksh and
> awk). Then, quoting is re-initiated with the second double-quote on line 5.
>
> However, I did try your script with ksh version: Version M
> 1993-12-28
> s+. It did indeed succeed without the escaped double-quotes. Then, I
> reran the script with line 5 modified like this:
>
> FS = "()"
>
> With that the older version of ksh failed with the error:
>
> line 2: syntax error at line 5: `(' unexpected
>
> With line 5 modified as:
>
> FS = \"()\"
>
> The script once again succeeded (albeit with a different answer because
> awk's FS had a different value).
>
> These variations seem to indicate that in older versions of ksh
> square
> brackets could be used as a quasi-quoting mechanism. But, as far as I
> know this /feature/ was not documented and should not have been
> relied-upon. Escaping the double-quotes on line 5 is the way to go.
>
> Terrence Doyle
>
> On 5/17/15 4:23 PM, lijo george wrote:
> > I observed a syntax error with a script in ksh versions starting from
> > 2012-08-01.
> > A minimal test case is given below.
> > Basically if the pattern "[()]" is used as field separator in awk, it
> > throws a syntax error.
> >
> > # ksh --version
> > version sh (AT&T Research) 93u+ 2012-08-01
> > # cat test-simple.ksh
> > NAWK=/usr/bin/nawk
> > TEST="abc(def)g)"
> > A="`echo $TEST | $NAWK '
> > BEGIN{
> > FS = "[()]"
> > }
> > /^a/ {
> > print $1
> > }
> > END{
> > #print $2
> > }'`"
> > print $A
> > # ksh test-simple.ksh
> > test-simple.ksh: line 2: syntax error at line 5: `(' unexpected
> >
> >
> > This used to work in the 2011-02-08 version.
> > Is this a bug or expected behaviour.
> >
> > From the sh_lex function in the lex.c file, I can see that there is a
> > check added for the pattern "[(" given below.
> > case S_EPAT:
> > epat:
> > if(fcgetc(n)==LPAREN && c!='[')
> >
> > But in the earlier version(2011-02-08), the corresponding check was
> >
> > case S_EPAT:
> > epat:
> > if(fcgetc(n)==LPAREN)
> >
> >
> > So I guess the extra check was added for some specific reason. In that
> > case, could someone please let me know the reason why this was added and
> > the syntax error is thrown.
> >
> > Thanks,
> > Lijo
> >
> >
> > _______________________________________________
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