Override Chrome policy in Linux

If you happen to have Google Chrome settings managed by your network administration, on Linux, the fixed settings are stored into JSON files in the folder:

/etc/opt/chrome/policies/

If you have write permissions, you can change the settings you want. You don’t even need to restart Chrome to the changes start working. This has been tested in Chrome 77.

Let Go website generate your documentation

When trying to figure out how go doc command works, I just found out that I don’t need to use it.

There’s an incredible feature of Go documentation website: it can generate and display the documentation of all your project, straight from GitHub – and other websites too. The generated HTML is very polished.

To use it, append your GitHub user name and repo to their URL, such as:

https://godoc.org/github.com/username/reponame

Even more interesting: all types and Go built-in types are automatically linked. And it also provides direct links to GitHub source files. On top of all that, it’s very fast. Written in Go, I suppose.

Being a C language admirer, the more I work with Go, the more I like its simplicity.

Using Go modules in separated local directories

Suppose I have a Go project, “foo”, which writes to the console. In this project, I have some .go files which have all the functions that actually write to the console.

Now I want to make these writing routines a separated module: “writer”, in another directory. I want two sibling directories: “foo” and “writer”. The “writer” will be used as a dependency within “foo”.

Within “writers” folder, run go mod init writer to create the go.mod file. Back in “foo”, edit its go.mod adding the new dependency:

module Foo

go 1.13.1

require (
  shoutergo v0.0.0
)

replace (
  shoutergo => ../shoutergo
)

The replace line will inform Go where to look for the module. Without it, Go will search in the internet, that’s why GitHub URLs work right away.

The version of the dependency, as far as I could find, is a Git tag, and to local modules it’s completely irrelevant, although necessary.

Now, in “foo”, we can import “writer” just like any other package:

import (
  "writer"
)

func main() {
  writer.SomeFunc()
}

As I keep learning Go and exploring the limits of the language, although I’m not entirely satisfied – lack of enums and namespaces –, I’m very pleased with its design choices with opted for simplicity. Feels like a better C.

How Go caches downloaded packages

Here I intend to summarize how the Go package cache system works, after spending half of my afternoon running tests and figuring out this weird thing.

First off, to create a new Go project outside the awful GOPATH directory, you run:

mkdir my-project
cd my-project
go mod init my-project

This will create a go.mod file.

To add a dependency from GitHub, you run:

go get github.com/username/reponame

This will create a go.sum file, which contains the dependency tree. The package files themselves will be downloaded and buried within ~/go/pkg/mod directory, so they are effectively cached at global, machine-wide scope.

To list the packages inside my-project, run:

go list ./...

This won’t list globally downloaded, cached dependencies installed with go get.

To list the packages installed (not the cached ones) globally, run:

go list ...

Downloaded dependencies will be listed if you are in my-project folder, and if they have been downloaded already. If you run the command above from within a project directory, it will download and install any missing packages for current project, and then they will be listed.

So, if you’re outside my-project directory, there’s no way to list globally cached packages.

There’s no way to remove a globally cached package from cache individually. All you can do is delete the whole cache, with:

go clean -cache -modcache -i -r

CSS grid with column flow, with a nested grid

This month I was trying to layout a very complex form in two columns, and I ended up with this CSS sorcery. It’s important to notice that the number of columns and rows must be tightly controlled via their widths and heights.