[9fans] p9p mk(1) syntax

[9fans] p9p mk(1) syntax

[dexen deVries]

in p9p mk, this works as expected:
foo = `{echo bar}

but the following does not -- rc(1) indicates syntax error:
foo = `{echo `{echo bar}}


strace indicates that mk(1) passes input to rc(1) with no closing braces at 
all.


i'm using MKSHELL = rc.

-- 
dexen deVries

[[[↓][→]]]

Take care of the luxuries and the necessities will take care of themselves.
                -- L. Long

Re: [9fans] p9p mk(1) syntax

[Friedrich Psiorz]

I don't think that the behavior is really unexpected ... the `{...} part
is interpreted by mk, but not the text between the braces. You probably
need to quote it if it contains braces itself.

Am 06.09.2013 13:03, schrieb dexen deVries:
> in p9p mk, this works as expected:
> foo = `{echo bar}
>
> but the following does not -- rc(1) indicates syntax error:
> foo = `{echo `{echo bar}}
>
>
> strace indicates that mk(1) passes input to rc(1) with no closing braces at
> all.
>
>
> i'm using MKSHELL = rc.
>

Re: [9fans] p9p mk(1) syntax

[erik quanstrom]

On Sat Sep  7 04:23:05 EDT 2013, f.psiorz@gmx.de wrote:
> I don't think that the behavior is really unexpected ... the `{...} part
> is interpreted by mk, but not the text between the braces. You probably
> need to quote it if it contains braces itself.
>

after looking at the code, it appears to me that this is an oversight,
that does not effect bourne-shell compatabiles.  we simply need to
count the `{s and subtract the }s, and when the count reachs 0
we're done.

(it appears that ' quoting is incorrect for bourne shell compatables,
and the interpretation of \ is incorrect for rc.)

- erik

; diffy -c lex.c
/n/dump/2013/0907/sys/src/cmd/mk/lex.c:67,73 - lex.c:67,73
  static int
  bquote(Biobuf *bp, Bufblock *buf)
  {
- 	int c, line, term;
+ 	int c, line, term, depth;
  	int start;

  	line = mkinline;
/n/dump/2013/0907/sys/src/cmd/mk/lex.c:79,88 - lex.c:79,91
  			;
  	} else
  		term = '`';		/* sh style */
+ 	depth = 1;

  	start = buf->current-buf->start;
  	for(;c > 0; c = nextrune(bp, 0)){
- 		if(c == term){
+ 		if(term == '}' && c == '`')
+ 			depth++;
+ 		if(c == term && --depth == 0){
  			insert(buf, '\n');
  			insert(buf,0);
  			buf->current = buf->start+start;

Re: [9fans] p9p mk(1) syntax

[cinap_lenrek]

why not this?

+ 		if(term == '}' && c == '{')
+ 			depth++;

--
cinap

Re: [9fans] p9p mk(1) syntax

[dexen deVries]

thanks to you both.

http://github.com/dexen/plan9port-custom/commit/6a67d4d8c97bc682737ae1cf59544fb4c969a105.patch

cinap's version also supports rc block statements; tested with:

MKSHELL = rc

foo = `{ echo aaa; { date; }; pwd; }
bar = `{ echo zzz `{ date } zzz }

test:VQ:
    echo foo $foo
    echo bar $bar

On Sat, Sep 7, 2013 at 5:05 PM,  <cinap_lenrek@gmx.de> wrote:
> why not this?
>
> +               if(term == '}' && c == '{')
> +                       depth++;
>
> --
> cinap
>

Re: [9fans] p9p mk(1) syntax

[erik quanstrom]

On Sat Sep  7 11:07:06 EDT 2013, cinap_lenrek@gmx.de wrote:
> why not this?
>
> + 		if(term == '}' && c == '{')
> + 			depth++;

this is a better idea, since it would properly deal with
z=`{x=y {echo $x}}

- erik

Re: [9fans] p9p mk(1) syntax

[arisawa]

single quotes are escaped?

On 2013/09/08, at 1:21, erik quanstrom <quanstro@quanstro.net> wrote:

> On Sat Sep  7 11:07:06 EDT 2013, cinap_lenrek@gmx.de wrote:
>> why not this?
>>
>> + 		if(term == '}' && c == '{')
>> + 			depth++;
>
> this is a better idea, since it would properly deal with
> z=`{x=y {echo $x}}
>
> - erik
>

Re: [9fans] p9p mk(1) syntax

[erik quanstrom]

> single quotes are escaped?

yes.

- erik

[9fans] p9p mk(1) syntax

[dexen deVries]

in p9p mk, this works as expected:
foo = `{echo bar}

but the following does not -- rc(1) indicates syntax error:
foo = `{echo `{echo bar}}


strace indicates that mk(1) passes input to rc(1) with no closing braces at 
all.


i'm using MKSHELL = rc.

-- 
dexen deVries

[[[↓][→]]]