Re: Saving commands from a session

[Vin Shelton <acs@alumni.princeton.edu>]

On Mon, Jan 12, 2015 at 12:19 PM, Mikael Magnusson <mikachu@gmail.com> wrote:
> On Mon, Jan 12, 2015 at 6:01 PM, Vin Shelton <acs@alumni.princeton.edu> wrote:
>> In addition to saving commands in .zhistory, I like to save commands
>> by session, so I can save and later search the sequence of commands I
>> executed at a particular time.  In order to do this, in .zlogout I
>> compared all commands in history against the date and time of the
>> first command saved:
>>
>> # Get the date and time of the first command in the shell history.
>> fc -lin -$HISTCMD -$((HISTCMD-1)) | read d t cmd
>>
>> # Ignore all commands that have the same date and time.
>> # They were read in when the shell started.
>> fc -lin -$HISTCMD | grep -v "^$d $t" >> $outfile
>>
>> I was never terribly impressed by the elegance of this solution, but
>> it worked, more or less (I believe it could drop the first command or
>> two I entered if they happened to have the same date and time as the
>> start of the shell).
>>
>> However, I recently started using
>>
>> setopt EXTENDED_HISTORY
>>
>> and this has the effect of keeping the original date and time the
>> command was executed in .zhistory, so when the historical commands are
>> read into the shell, they no longer all have the same date and time.
>>
>> Is there a more elegant way to save only those commands that have been
>> executed in this instance of the shell?
>
> Maybe you want to write out each entry incrementally from
> zshaddhistory() instead? Zsh does track which history entries are
> "local" and which are imported from history, but I don't believe you
> can directly access this information.

Thanks, Mikael.  I followed your advice and am now using zshaddhistory().

Regards,
  Vin