Re: TODO item: add \# which lists line numbers, and allows command execution

On 9/8/07, Sibte Abbas <sibtay(at)gmail(dot)com> wrote:
>
>
> Hi all,
>
> Realizing that the mentioned TODO item discussed at http://archives.postgresql.org/pgsql-hackers/2006-12/msg00255.php
> <http://archives.postgresql.org/pgsql-hackers/2006-12/msg00255.php> can be
> useful for myself and others as well, I would like to go ahead and implement
> it.
>
> Synopsis:
> ======
>
> Sticking to the syntax and semantics which Joshua already mentioned in the
> thread:
>
> \#: displays the command history. Like \s but prefixes the lines with line
> numbers
>
> \# <line_no>: executes the command(if any) executed at the line specified
> by line_no
>
>
> Display the history contents:
> =================
>
> Well the answer to this pretty much lies in the \s (without any filename)
> implementation. However \s simply writes the contents of the history to the
> TTY while \# would prefix all the history lines with their respective line
> numbers.
>
> Because of this difference, we'll have to employ a more flexible approach
> rather than simply using the write_history() function.
>
> A solution to this is to use history_list() function to get a list of
> HIST_ENTRY structures and simply display them as per our needs i.e. to
> prefix each line with incrementing numbers in our case.
>
> Execute a line based on line number:
> ======================
>
> For this we can simply use the history_get(int offset) function of the gnu
> history api to return a HIST_ENTRY structure corresponding to the given
> offset.
>
> The returned HIST_ENTRY can then be used to access the command that was
> executed at that specific line number.
>
> Comments are welcomed.
>
> regards,
> --
> Sibte Abbas
>

Patch submitted to pgsql-patches.

regards,
--
Sibte Abbas