6 ms·

I wonder what he was using the up arrow key for in the shell.

Fr3ck 5y ago
Doesn’t the up arrow key show the last command executed?
dekhn 5y ago
In those days people mainly used ! expansion. https://en.wikipedia.org/wiki/C_shell#History https://en.wikipedia.org/wiki/C_shell#History. I know many people who are incredibly good at using ! expansion to edit previous commands ("change that command 5 lines ago to rm -rf this other folder") but it's a bit of a footgun.
- jolmg 5y ago
  Right, but the up arrow didn't get in their way, right? So why get mad? I imagine that how it worked for them before is that the up arrow would move the cursor to the previous line into the output of the previous command, while feeding the arrow key escape sequences to the shell prompt as part of the command. IOW, a pretty useless and annoying key right? Why even press it? How did they notice readline?
  - dekhn 5y ago
    from what I can tell he was looking hard for problems. He also noticed that if you ran 9 "yes" commands on a 8 core machine, the CPU wasn't allocated in 8/9ths units (one process always got a lot less CPU). he was used to much more predictible CPU scheduler on multiprocessor systems (spoilt by TruCluster). Linux later adopted a better scheduler (fair share) so imho he was right on that one, even if "yes" is a terribly performance metric.
    - fragmede 5y ago
      It seems the lesson here is that changing things out from under someone isn't a good look. What would have been the cost in not changing users' shells for them?
      - tedunangst 5y ago
        Everybody else has a worse shell.
- vermaden 5y ago
  Depends how you use it. If you just want to execute it then it is a footgun - using only the !command syntax. If you use the !command:p syntax then you are just printing what command has been executed instead of invoking it. Example. % uname FreeBSD % !uname uname FreeBSD % !uname:p uname %
  - deleted 5y ago
    [deleted]
azinman2 5y ago
How do you know he was a he?
- dekhn 5y ago
  without certainty, prior probabilities suggest a technically inclined research leader would be male.
  - azinman2 5y ago
    And perpetuating these biases is what makes it feel lonely and not welcoming to be a woman in engineering.
    - guilhas 5y ago
      A woman in engineering should know that just because things have been probable in the past does not mean they will in the future For a guy growing around computers it has also been pretty lonely, more girls would have been welcome at any stage...
      - cassonmars 5y ago
        Speaking from the other side of that perspective — being one of a few women in a CS program can be a very uncomfortable experience, especially a decade or two ago.
      - wolverine876 5y ago
        > A woman in engineering should know that just because things have been probable in the past does not mean they will in the future I don't think I would tell someone what they "should" know. That 'knowledge' seems like an unlikely possibility: I think it probable that significant discrimination against women in tech will (very unfortunately) continue for another generation, at least. One signal to me is that many reject it in every way: Denial, anger, etc.
        5y ago

Doesn’t the up arrow key show the last command executed?

In those days people mainly used ! expansion. https://en.wikipedia.org/wiki/C_shell#History https://en.wikipedia.org/wiki/C_shell#History. I know many people who are incredibly good at using ! expansion to edit previous commands ("change that command 5 lines ago to rm -rf this other folder") but it's a bit of a footgun.

jolmg 5y ago
Right, but the up arrow didn't get in their way, right? So why get mad? I imagine that how it worked for them before is that the up arrow would move the cursor to the previous line into the output of the previous command, while feeding the arrow key escape sequences to the shell prompt as part of the command. IOW, a pretty useless and annoying key right? Why even press it? How did they notice readline?
- dekhn 5y ago
  from what I can tell he was looking hard for problems. He also noticed that if you ran 9 "yes" commands on a 8 core machine, the CPU wasn't allocated in 8/9ths units (one process always got a lot less CPU). he was used to much more predictible CPU scheduler on multiprocessor systems (spoilt by TruCluster). Linux later adopted a better scheduler (fair share) so imho he was right on that one, even if "yes" is a terribly performance metric.
  - fragmede 5y ago
    It seems the lesson here is that changing things out from under someone isn't a good look. What would have been the cost in not changing users' shells for them?
    - tedunangst 5y ago
      Everybody else has a worse shell.
vermaden 5y ago
Depends how you use it. If you just want to execute it then it is a footgun - using only the !command syntax. If you use the !command:p syntax then you are just printing what command has been executed instead of invoking it. Example. % uname FreeBSD % !uname uname FreeBSD % !uname:p uname %
- deleted 5y ago
  [deleted]

azinman2 5y ago

How do you know he was a he?

dekhn 5y ago
without certainty, prior probabilities suggest a technically inclined research leader would be male.
- azinman2 5y ago
  And perpetuating these biases is what makes it feel lonely and not welcoming to be a woman in engineering.
  - guilhas 5y ago
    A woman in engineering should know that just because things have been probable in the past does not mean they will in the future For a guy growing around computers it has also been pretty lonely, more girls would have been welcome at any stage...
    - cassonmars 5y ago
      Speaking from the other side of that perspective — being one of a few women in a CS program can be a very uncomfortable experience, especially a decade or two ago.
    - wolverine876 5y ago
      > A woman in engineering should know that just because things have been probable in the past does not mean they will in the future I don't think I would tell someone what they "should" know. That 'knowledge' seems like an unlikely possibility: I think it probable that significant discrimination against women in tech will (very unfortunately) continue for another generation, at least. One signal to me is that many reject it in every way: Denial, anger, etc.
      - 5y ago