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
>
>
> _______________________________________________
> ast-developers mailing list
> ast-developers@lists.research.att.com
> http://lists.research.att.com/mailman/listinfo/ast-developers
_______________________________________________
ast-developers mailing list
ast-developers@lists.research.att.com
http://lists.research.att.com/mailman/listinfo/ast-developers
