Nushell

My website is implemented through Hugo, with content sources in Markdown. Metadata is added through a so-called "front matter" header within Markdown files. I noticed date metadata (front matter) was missing on content pages and consequently had 2001 on RSS feeds.

I used Nushell to en-mass add page dates after-the-fact, with date values determined through Git.

# Determine pages with missing date front matter (may be missing pages that have `date = ` as content)
glob **/*.md | where {|x| $x | open | not ($in | str contains 'date = ') } | save missing.json

# Determine content creation dates through Git add authoring date
open missing.json | wrap path | upsert date {|x| git log '--follow' '--diff-filter=A' '--format=%ad' '--date=iso' '--' $x.path | into datetime } | save dates.json

# Prepend date TOML front matter to closing fence
open dates.json | each {|x| $x.path | open --raw | str replace "\r\n+++\r\n" $"\r\ndate = \"($x.date | format date '%Y-%m-%d %H:%M:%S')\"\r\n+++\r\n" | collect | save -f $x.path }

Example [inline] result/fixup:

date = "2022-08-07 18:31:18"
+++

Some work details and manual cleanup (e.g. pages with resource front matter where the date declaration must be placed before them) omitted.

I added two solutions to the Rosetta Code FizBuzz page in Nu.

The one that was already there was quite confusing/non-intuitive to me; with string determination, and by index value fixups.

I like the match solution because it's structurally obvious and demonstrates the record-field-value match and logical case matching:

1..100 | each {
  { x: $in, mod3: ($in mod 3), mod5: ($in mod 5), }
  | match $in {
    { mod3: 0, mod5: 0, } => 'FizzBuz',
    { mod3: 0, mod5: _, } => 'Fizz',
    { mod3: _, mod5: 0, } => 'Buzz',
                        _ => $in.x
  }
} | str join "\n"

Do you have alternative suggestions or improvements?

Nushell is a powerful shell and scripting language with strong typing, querying, and piping functionalities.

This release adds runtime pipeline input type checking, several new commands and operators, and various other miscellaneous improvements.

I track and version my Nushell environment and configuration in a public repository.

I added a GitHub Actions workflow that tests these files. That will ensure a more defined environment and prerequisites/assumptions, given that they have to be set up in the workflow configuration. Given that I mostly work on Windows, but set up the CI to run on Linux/Ubuntu, it will also ensure platform neutrality.

Since Nushell version 0.101.0, there's no need for a default, base env.nu or config.nu, and the nu binary can be called with only the custom, minimal env and config files.

The nu binary offers --env-config and --config parameters.

I noticed that when using them, errors do not lead to error exist codes; nu will continue execution and report success despite env or config not loading [correctly]. (Bug Ticket #14745)

Do you version your environment configuration? Only locally, or with a hosted repository as a backup or to share? Do you run automated tests on it?

• Simplified Startup Configuration
• path self
• chunk-by
• term query
• merge deep
• WASM support (again)
• sys net inclueds new columns mac and ip
• raw string pattern matching
• dates can now be added to durations
• additional explore keybinds
• version in startup banner
• input --default
• PowerShell script invocation on Windows
• new introspection tools

Breaking Changes:

• ++ operator, stricter command signature parsing (resolves silent parse errors)
• group-by now supports "groupers" (multiple criteria)
• timeit
• sys cpu
• from csv and from tsv
• std/iter scan
• completion sorting in custom completers, import module naming with normalization
• display_output hook
• du flag changes
• Code specific environment variables updated during source

Command dl opus to download highest quality audio as or into an opus file through yt-dlp.

Add to config.nu:

# Download highest quality Opus audio as/into .opus file
def "dl opus" [url: string] {
    yt-dlp --extract-audio --audio-quality 0 --audio-format opus $"($url)"
}

Usage:

dl opus <url>

I have set up dl as an alias for yt-dlp via alias dl = yt-dlp. The def above adds an overlaying sub-command.