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Comment by helsinkiandrew | Hacker News Reader

If any one has tried this, can you confirm whether it copes with having multiple shells overwriting the history files

There is nothing more disappointing than not being able to find the cool command line I used a week ago because the shell I opened briefly and forgot about has overwritten it - maybe that's my poor setup though

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I use this in my bash profile:

  export HISTSIZE=65535
  shopt -s histappend
  PROMPT_COMMAND="history -a;$PROMPT_COMMAND"

I miss it though on other computers and suffer until I set it up on new ones.

> 65535

Why limit yourself to 16bit?

Just a big enough number and I punish myself as I would like to create my own shell/terminal thing and use that instead.

I hope you get to it eventually, but if you do, consider 32 bits instead.

Computers are fast, memory is cheap and 16 bits is not that big. My .bash_history is clocking at 55814 now with dedup on. Granted, it's beeing going for years, but still, no reason to punish yourself.

>>>55814 now with dedup on. Granted, it's beeing going for years

As you can see, Mr. Anderson, we've been keeping our eye on you for some time now

I wish

Important! My history file on my laptop is up to 200,342.

With dedup on? That’s some serious typing.

Dedup off, since I use my history to reconstruct things I've done and for that I want the full sequence of commands.

Checking now it's 104,545 unique commands. It goes back to April 2012.

Note that this is just my laptop; things I've run on my work computer or when ssh'd somewhere else aren't included.

The last time I attempted this, it caused going back through the history in a separate shell to show entries from all other existing shells in order. Since I use each shell as separate workspaces, the clashing was unbearable. Now, I do:

    # Undocumented feature which sets the size to "unlimited".
    # http://stackoverflow.com/questions/9457233/unlimited-bash-history
    export HISTFILESIZE=
    export HISTSIZE=

and just depend on exiting my shells to store data long term.

If you're using bash 4.3 (released 2014) or higher you could convert this from using an "undocumented feature" to use the documented feature that does the same...

> "Numeric values less than zero result in every command being saved on the history list (there is no limit)."

  export HISTFILESIZE=-1
  export HISTSIZE=-1

Yes, mcfly can handle that.

I've been using it for the last couple of years. My history file has around a quarter million entries so far.

JFC

If you use bash I'm assuming you don't have ...

export HISTCONTROL=ignoreboth:erasedups

Somewhere in your rc files.

If you do, ehe, that's some serious variety of work on the CLI !

I didn't mean the bash history file but the mcfly internal one.

mcfly doesn't remove dups and also stores additional info about the executed commands like pwd, timestamp and return code.

Now I'm wondering if I overuse / abuse my CLI. I don't find this to be a surprising number of deduped entries in the least.

This is my least favourite thing about shell history as well. It fails at being shell history log, because it's dropping more than it retains.

I hate that too but it’s worth noting that this is a bashism. It’s not a problem with some other alternative shells.

Yep, zsh, and most likely fish and other shells manage to keep all your commands in the history, no matter how many sessions you open.

I find this can be a bit messy because VS code runs lots of commands in the background that pollute the history with extremely verbose commands.

Why does it run them in interactive shells? Not surpising given it’s Microsoft, but still worth reporting an issue.

I can’t speak for VSC specifically (I don’t like their terminal emulator so don’t have enough experience using it) but I do know some other applications “paste” (for want a better word) commands into the script interactive shell because they purpose of the shell being open is to provide a REPL and the GUI application just provides a few useful graphical hooks to it.

Regarding the history problem, there’s likely a flag VSC can pass to Zsh to disable writing to history for that session.

Edit: looks like there are several ways: https://unix.stackexchange.com/questions/692913/temporarily-...

Bash was written when disks were a few megabytes. It’s trivial to tell it to keep an infinite log, as others have commented.

The issue isn’t the length of the history. It’s that the history is written to at the end of the bash session. So if you have multiple sessions open then one session with overwrite another session log.

Even if your point was right though, I’d argue that because Bash is still being maintained, any defaults originating from the 80s should be updated. Yes, I know there are low footprint environments out there that still have writable storage in the region of a few megabytes (or even less), but we have other shells for those use cases.

Changing defaults can have unexpected consequences, especially ones that have storage implication and especially in programs that are so tied to scripting.

I agree that the default is unfortunate but the points above seem more important.

Changing bash history retention wouldn’t affect scripts. Scripts don’t write to the history log.

And bash has already changed numerous features over the years.

shopt -s histappend together with HISTSIZE=99999 and HISTFILESIZE=99999 into your .bashrc should do the trick.

    promptFunc() {
        echo "$(date +%Y-%m-%d--%H-%M-%S) $(hostname) $PWD $(history 1)" \
          >> ~/.full_history
    }
    PROMPT_COMMAND=promptFunc

Or, in zsh:

    precmd() {
        echo "$(date +%Y-%m-%d--%H-%M-%S) $(hostname) $PWD $(history -1)" \
          >> ~/.full_history
    }

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