Re: add line number as prompt option to psql - Mailing list pgsql-hackers

On Tue, Aug 26, 2014 at 10:23 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> On 2014-08-21 11:43:48 +0900, Sawada Masahiko wrote:
>> On Wed, Aug 20, 2014 at 9:00 PM, Jeevan Chalke
>> <jeevan.chalke@enterprisedb.com> wrote:
>> > Hi,
>> >
>> > I have reviewed this:
>> >
>> > I have initialize cur_lineno to UINTMAX - 2. And then observed following
>> > behaviour to check wrap-around.
>> >
>> > postgres=# \set PROMPT1 '%/[%l]%R%# '
>> > postgres[18446744073709551613]=# \set PROMPT2 '%/[%l]%R%# '
>> > postgres[18446744073709551613]=# select
>> > postgres[18446744073709551614]-# a
>> > postgres[18446744073709551615]-# ,
>> > postgres[0]-# b
>> > postgres[1]-# from
>> > postgres[2]-# dual;
>> >
>> > It is wrapping to 0, where as line number always start with 1. Any issues?
>> >
>> > I would like to ignore this as UINTMAX lines are too much for a input
>> > buffer to hold. It is almost NIL chances to hit this.
>> >
>> >
>> > However, I think you need to use UINT64_FORMAT while printing uint64
>> > number. Currently it is %u which wrap-around at UINT_MAX.
>> > See how pset.lineno is displayed.
>> >
>> > Apart from this, I didn't see any issues in my testing.
>> >
>> > Patch applies cleanly. make/make install/initdb/make check all are well.
>> >
>>
>> Thank you for reviewing the patch!
>> Attached patch is latest version patch.
>> I modified the output format of cur_lineno.
>
> I like the feature - and I wanted to commit it, but enough stuff turned
> up that I needed to fix that it warrants some new testing.
>
> Stuff I've changed:
> * removed include of limits.h - that probably was a rememnant from a
>   previous version
> * removed a trailing whitespace
> * expanded the documentation about %l. "The current line number" isn't
>   very clear. Of a file? Of all lines ever entered in psql? It's now
>   "The line number inside the current statement, starting from
>   <literal>1</>."
> * Correspondingly I've changed the variable's name to stmt_lineno.
> * COPY FROM ... STDIN/PROMPT3 was broken because a) the promp was only generated
>   once b) the lineno wasn't incremented.
> * CTRL-C didn't reset the line number.
> *  Unfortunately I've notice here that the prompting is broken in some
> common cases:
>
> postgres[1]=# SELECT 1,
> postgres[2]-# '2
> postgres[2]'# 2b
> postgres[2]'# 2c
> postgres[2]'# 2d',
> postgres[3]-# 3;
> ┌──────────┬──────────┬──────────┐
> │ ?column? │ ?column? │ ?column? │
> ├──────────┼──────────┼──────────┤
> │        1 │ 2       ↵│        3 │
> │          │ 2b      ↵│          │
> │          │ 2c      ↵│          │
> │          │ 2d       │          │
> └──────────┴──────────┴──────────┘
> (1 row)
>
> postgres[1]=# SELECT 1,
> '2
> 2b
> 2c
> 2d',
> 3
> postgres[7]-#
>
> That's rather inconsistent...
>
>
> I've attached my version of the patch. Note that I've got rid of all the
> PSCAN_INCOMPLETE checks... Please test!
>

Thank you for review comment and improving the patch!
I tested it.
Your patch always increment line number even if there is no input line
as follows.

postgres[1]=#
postgres[2]=# select
postgres[3]-# ,
postgres[4]-# from
postgres[5]-# hoge;
ERROR:  syntax error at or near "," at character 8
STATEMENT:  select
,
from
hoge;
ERROR:  syntax error at or near ","
LINE 2: ,
        ^
Actually error syntax is in line 2 as postgres reported.
But it is inconsistent.
Attached patch is resolve above behavior based on your version patch.

Regards,

-------
Sawada Masahiko