History in batch operation
g1ul10
AFAIK presently the history function of gnuplot works exclusively in
an interactive session. Moreover if I use
gnuplot -
the input is interactive BUT I do not have history. Why is it so? I
think it would be nice to access history from batch script and,
surely, from an interactive session started with the special '-'
filename.
Looking at the code, I've notice that in plot.c the history set up
part is inside an if (interactive && term != 0){...} condition. Just
moving this part out of the 'if' gave me access to history from batch
(for instance gnuplot -e 'history 10' print the list of last 10
commands). I surely made horrible programming mistakes, BUT I think I
proved that the thing is feasible :-). I work in Linux. The patch
follows.
Giulio
Index: src/plot.c
===================================================================
RCS file: /cvsroot/gnuplot/gnuplot/src/plot.c,v
retrieving revision 1.104
diff -r1.104 plot.c
540d539
< if (interactive && term != 0) { /* not unknown */
569c568
<
---
> if (interactive && term != 0) { /* not unknown */
Hans-Bernhard Bröker
> Hi all,
> AFAIK presently the history function of gnuplot works exclusively in
> an interactive session. Moreover if I use
>
> gnuplot -
>
> the input is interactive BUT I do not have history. Why is it so?
Because gnuplot, in this case, is not in interactive mode of operation.
The '-' command-line argument is meant for use with programs
controlling gnuplot from the outside (after having loaded some scripts
first), not for actual interactive usage by people.
g1ul10
wrote:
Thank you for your reply. When I'm doing "data exploration" I like to
be able to plot directly
from the command line. For this purpose I wrote a little shell
function 'gbplot' that I use,
for example, in this way
program_that_generates_data | gbplot -i plot u 0:1 w lp
the script opens a terminal controlling a gnuplot session, displays
the plot, and enters
and interactive session in whcih I can change axes scale or set log or
whatever seems
interesting to do. The function code can be found here (it's a zsh
function; does not work
in bash) http://giulio.bottazzi.googlepages.com/zshrc This method is
more practical than
first opening a gnuplot session and then use
plot "< program_that_generates_data"
Essentially the script works by building two suitably defined
temporary files 'CMDFILE' and
'ENDFILE' and starts gnuplot with
gnuplot $CMDFILE - $ENDFILE
Everything works nicely (because gnuplot is a fantastic program) APART
being able to access
previous history. I miss this feature because being data exploration a
back and forth exercise, I
often find myself re-typing the same lines.
Sorry for the long post. I think it was useful to clarify why I think
this feature could be of some use.
Best,
G.
P.S.: By the way, gnuplot's help says:
To launch an interactive session after an initialization file
"header" and
followed by another command file "trailer":
gnuplot header - trailer