Can I retrieve the full history of commands from a Perl pdl2 shell (like history in bash)?

I am using pdl2 shell, how can 开发者_C百科I list all my commands history?

You can find your history in $HOME/.perldl_hist

This may or may not be dependent on having Term::ReadLine::Gnu installed (which I have by default).

If you want access to your history within pdl, then just use the up arrow key for the previous commands, or type ^R (control-r) then a text that you want to search back for (hitting ^r repeatedly for matches further back).

$ pdl
perlDL shell v1.354
...blah blah blah...
pdl> print 1+1
2
pdl> print 2+2
4
pdl> quit

$ cat ~/.perldl_hist 
print 1+1
print 2+2
$ 

EDIT: To find the history from within pdl, do the following:

$ pdl
pdl> print join "\n", $PERLDL::TERM->GetHistory

The $PERLDL::TERM->GetHistory returns an array of the current history. It's just a regular array, so you can do whatever you like with it. For example, to find all of your recent histogram operations involving a piddle named mypdl, you could do:

pdl> print join "\n", grep { /histogram/ && /mypdl/ } $PERLDL::TERM->GetHistory

From the PDL documentation (i.e., pdldoc perldl):

History mechanism
  If you have the perl modules ReadLines and ReadKeys installed, then
  perldl supports a history and line-editing mechanism using editing keys
  similar to emacs. The last 500 commands are always stored in the file
  .perldl_hist in your home directory between sessions. Set
  $PERLDL::HISTFILESIZE to change the number of lines saved. The command
  "l [number]" shows you the last "number" commands you typed where
  "number" defaults to 20.

The l command lists your history if you have a suitable readline installed.