I think the issue is that history is a shell built-in and not an actual program (ie. external command) and it typically only works in an interactive shell session.
A workaround could be to access the $HISTFILE directly:
{cat $HISTFILE | grep ...
Of course, you can use also just do:
{grep -e ... $HISTFILE | ...}
if you are opposed to the cat at the beginning.
I tried using cat but I got the same result. I must admit I wasn't aware that history is a shell built in and not a program. Given that is the case, would it not be very difficult to get the contents of history int o a temporary file from a shell script as I am attempting to do? Here is the new line which I attempted:
{cat $HISTFILE | grep -e 'pacman -S\s' -e 'pacman -R\s' -e 'yay -S\s' -e 'yay -R\s' | tail -n 50} > ~/history_installed
An alternative to making a shell script is to make an alias or a function instead. That way, it runs in your current shell session and you can access the history command.
Additionally, you could always dump the output of the history command outside the shell script and then run the shell script on that file after you have dumped it.
I managed to get it working with an alias, not sure how it didn't come to me before! I am however still curious if it is possible to achieve the same result through a script, and if so how that would be done, so if its alright I'll leave this unmarked as solved for a short while longer in the hope a solution is given by someone. Thank you!
I don't know zsh, but the curly brackets like that are not correct in posix sh. { commands; } is correct. { history | grep -e 'pacman -S\s' -e 'pacman -R\s' -e 'yay -S\s' -e 'yay -R\s' | tail -n 50; } > ~/history_installed I think that fixes it. Also check out shellcheck if you don't have already.
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