Dave Cheney recently posted another little Go pop quiz on Twitter,and as usual I learned something interesting from it. Let's startwith his tweet :

#golang pop quiz: what does this program print?

package main

import (    "crypto/sha1"    "fmt")func main() {    input := []byte("Hello, playground")    hash := sha1.Sum(input)[:5]    fmt.Println(hash)}

To my surprise, here is

If you have NFS filesystems with directories that are not worldaccessible, and people mount FUSE filesystems at spots under thosedirectories, you are probably going to have problems in modern Linuxkernels. Specifically, it is very difficult to unmount these FUSEmounts (even if the program providing the FUSE filesystem exits).

Here is what happens:

; ls -ld .; stat -f -c '%T' .drwx--S--- 108 cks itdirgrp 242 Sep 25 22

There are any number of programs and systems that store passwordsfor you, most prominently browsers with their remembered websitepasswords. It's very common for these programs to ask you to set amaster password that will secure the passwords they store and benecessary to unlock those passwords. One of my peculiarities isthat I refuse to set up such master passwords; this shows up mostoften in browsers, but I stick to it elsewhere as well. The fundamentalreason why I don't do this because I don'

Despite periodic qualms over Chrome extensions, I've been using Chrome for what is now along time . However, that's a bitmisleading of a statement, because I don't really use Chrome in aconventional way. Basically all of what I do with Chrome is useincognito mode as my 'just make this site work, I don't care' browser , with Javascript and so on all enabled in away that I don't normally do. For a long time this also had

When I wrote my entry on some differences between various versionsof ed(1) , I forgot to check the SingleUnix Specification to see if it has anything to say about ed . It turns out that itdoes, and ed ispart of the 'Shell & Utilities' section.

SUS ed is mostly the same as FreeBSD ed , which is kind of whatI think of as 'the baseline modern ed '. SUS ed requires that s support a bunch of flags for printing the results (only GNU ed

Today, the versions of ed(1) that people are most likely toencounter and experiment with are GNU ed on Linux,and FreeBSD ed and OpenBSD ed on their respectivesystems. GNU ed is a new implementation written from scratch, whileI believe that the *BSD ed is a descendant from the original V7ed by way of 4.x BSD ed, such as 4.4BSD ed .However, a great deal of what's said about ed(1) , especially instuff from

Over on Mastodon, I had a database opinion :

Obvious database hot take: your stored data always has a schema,unless your code neither reads nor writes it as anything except anopaque blob. What NoSQL changes is how many places that schema existsand how easy it is to have multiple schemas for your data.

(SQL allows multiple schemas too. You just change what fields mean inyour code, reuse them, extend them, etc etc.)

One schema that your data has is implicit in what data fields

One of the things that is frequently said about ed(1) is that it remains useful for non-interactive modificationsto files, for example as part of shell scripts. I even mentionedthis as a good use of ed today in my entry on why ed is nota good (interactive) editor today ,and I stand by that. But, well, there is a problem with using ed this way, and that problem is why I only very rarely actually use ed for scripted modifications to files.

The

Recently, HL left a comment on my entry about Ubuntu bug reportsbeing useless pointing out that part ofthe problem is Ubuntu's "Universe" repository.To quote HL:

The issue is of course that Universe is essentially a static snapshotof Debian unstable at the time of the relevant Ubuntu release. Someupdates do happen, generally if someone contributes them, but Ubuntudoes not consider the huge set of packages that only exist in Universeto actually be supported. [...] (In many cases it