Merge bc767a0ad3 into dce54bd689

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1521 TILs and counting..._
+_1527 TILs and counting..._
 
 ---
 
@@ -402,6 +402,8 @@ _1521 TILs and counting..._
 - [Do Something N Times](go/do-something-n-times.md)
 - [Find Executables Installed By Go](go/find-executables-installed-by-go.md)
 - [Not So Random](go/not-so-random.md)
+- [Parse A String Into Individual Fields](go/parse-a-string-into-individual-fields.md)
+- [Parse Flags From CLI Arguments](go/parse-flags-from-cli-arguments.md)
 - [Replace The Current Process With An External Command](go/replace-the-current-process-with-an-external-command.md)
 - [Sleep For A Duration](go/sleep-for-a-duration.md)
 - [Upgrading From An Older Version On Mac](go/upgrading-from-an-older-version-on-mac.md)
@@ -457,6 +459,7 @@ _1521 TILs and counting..._
 - [Get Random Images From Unsplash](internet/get-random-images-from-unsplash.md)
 - [Search Tweets By Author](internet/search-tweets-by-author.md)
 - [Show All Pivotal Stories With Blockers](internet/show-all-pivotal-stories-with-blockers.md)
+- [Verify Site Ownership With DNS Record](internet/verify-site-ownership-with-dns-record.md)
 
 ### Java
 
@@ -573,6 +576,7 @@ _1521 TILs and counting..._
 ### jj
 
 - [Colocate jj And git Directories For Project](jj/colocate-jj-and-git-directories-for-project.md)
+- [Find System-wide Config File For User](jj/find-system-wide-config-file-for-user.md)
 
 ### jq
 
@@ -636,6 +640,7 @@ _1521 TILs and counting..._
 - [Specify App When Opening From Command Line](mac/specify-app-when-opening-from-command-line.md)
 - [Use Default Screenshot Shortcuts With CleanShot X](mac/use-default-screenshot-shortcuts-with-cleanshot-x.md)
 - [View All Windows Of The Current App](mac/view-all-windows-of-the-current-app.md)
+- [Write System Clipboard To A File](mac/write-system-clipboard-to-a-file.md)
 
 ### MongoDB
 
@@ -774,6 +779,7 @@ _1521 TILs and counting..._
 - [Escaping String Literals With Dollar Quoting](postgres/escaping-string-literals-with-dollar-quoting.md)
 - [Export Query Results To A CSV](postgres/export-query-results-to-a-csv.md)
 - [Extracting Nested JSON Data](postgres/extracting-nested-json-data.md)
+- [Fetch Specific Number Of Results](postgres/fetch-specific-number-of-results.md)
 - [Find Duplicate Records In Table Without Unique Id](postgres/find-duplicate-records-in-table-without-unique-id.md)
 - [Find Records That Contain Duplicate Values](postgres/find-records-that-contain-duplicate-values.md)
 - [Find Records That Have Multiple Associated Records](postgres/find-records-that-have-multiple-associated-records.md)

go/parse-a-string-into-individual-fields.md

@@ -0,0 +1,39 @@
+# Parse A String Into Individual Fields
+
+Let's say you're reading in data from a file or otherwise dealing with an
+arbitrary string of data. If that string has a series of values separated by
+whitespace, you can parse it into individual fields with
+[`strings.Fields`](https://pkg.go.dev/strings#Fields).
+
+```go
+import (
+	"fmt"
+	"strings"
+)
+
+func main() {
+	data := "3 5 2 6 7 1 9"
+	fields := strings.Fields(data)
+
+	fmt.Printf("Fields: %v", fields)
+	// [3 5 2 6 7 1 9]
+}
+```
+
+Here is another example where we can see that `strings.Fields` deals with
+multiple whitespace and surrounding whitespace:
+
+```go
+import (
+	"fmt"
+	"strings"
+)
+
+func main() {
+	data := "  go  java c++ rust "
+	fields := strings.Fields(data)
+
+	fmt.Printf("%v", fields)
+	// [go java c++ rust]
+}
+```

go/parse-flags-from-cli-arguments.md

@@ -0,0 +1,65 @@
+# Parse Flags From CLI Arguments
+
+Though we can grab the arguments to a Go program from `os.Args`, it requires
+some manual parsing. With the built-in `flag` package, we can declare specific
+flags our program accepts, by type. When we parse them, they will be separated
+out from the rest of the positional arguments.
+
+Here is an example of the program that accepts a boolean `debug` flag. This
+will work with either `-debug` or `--debug`.
+
+```go
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+)
+
+func main() {
+	var debug bool
+	flag.BoolVar(&debug, "debug", false, "turns on debug mode, extra logging")
+	flag.Parse()
+
+	positionalArgs := flag.Args()
+
+	if len(positionalArgs) < 1 {
+		fmt.Println("Please specify which part to run: 1 or 2")
+		os.Exit(1)
+	}
+
+	if debug {
+		fmt.Println("We are in debug mode...")
+		fmt.Println("Received the following argument:", positionalArgs[0])
+	}
+
+	// ...
+}
+```
+
+We can run the program in debug mode like so:
+
+```bash
+$ go run . --debug 123
+We are in debug mode...
+Received the following argument: 123
+```
+
+We can also take advantage of the `help` flag that we get for free:
+
+```bash
+$ go run . --help
+Usage of /var/folders/62/lx9pcjbs1zbd83zg6twwym2r0000gn/T/go-build3212087168/b001/exe/test:
+  -debug
+        turns on debug mode, extra logging
+```
+
+Note: any recognized flags need to come before any of the position arguments.
+The `debug` flag won't be picked up if we run the program like this:
+
+```bash
+$ go run . 123 --debug
+```
+
+[source](https://pkg.go.dev/flag)

internet/verify-site-ownership-with-dns-record.md

@@ -0,0 +1,28 @@
+# Verify Site Ownership With DNS Record
+
+To run your site through Google Search Console and get detailed reports, you
+need to verify that you own the site. There are several manual ways of doing
+this that involve sticking a value unique to your URL in a file or header tag.
+There is a better way though.
+
+By adding a TXT DNS record wherever you domain's DNS is managed, you can prove
+to Google that you own the domain. That verification applies to all paths and
+subdomains of that domain.
+
+Some providers like Cloudflare have a mostly-automated process for this that
+Google can hook into as long as you grant permission via OAuth.
+
+You can also manually create the TXT record if necessary.
+
+Either way, it will look something like:
+
+```bash
+$ dig -t TXT visualmode.dev
+
+;; ANSWER SECTION:
+visualmode.dev.         377     IN      TXT     "google-site-verification=MBZ2S2fhnh2gHRxFniRrYW-O6mdyimJDRFj-f
+vblwtk"
+```
+
+More details are provided in the [Google Search Console
+docs](https://support.google.com/webmasters/answer/9008080?hl=en#domain_name_verification).

jj/find-system-wide-config-file-for-user.md

@@ -0,0 +1,25 @@
+# Find System-wide Config File For User
+
+The `jj` CLI can be configured in a couple different places. When I recently
+ran a `jj config` command, I was curious where specifically it was getting set.
+Those changes didn't appear in the repo's config (`./.jj/repo/config.toml`).
+That makes sense since it would only apply to that repo. So, where is the
+system-wide config file?
+
+The following commond shows where on your machine it is located.
+
+```bash
+$ jj config path --user
+/Users/jbranchaud/Library/Application Support/jj/config.toml
+```
+
+Now, the next time I set a config like this:
+
+```bash
+$ jj config set --user ui.paginate never
+```
+
+or want to check what other config options are set to, I can visit that path
+and take a look.
+
+[source](https://github.com/martinvonz/jj/blob/main/docs/config.md)

mac/write-system-clipboard-to-a-file.md

@@ -0,0 +1,19 @@
+# Write System Clipboard To A File
+
+MacOS has two CLI utilities `pbcopy` and `pbpaste` which, respectively, copy
+_to_ and paste _from_ the system clipboard via the CLI.
+
+Let's say I've just copied a large block of text from somewhere onto my system
+clipboard. I now want to paste that into a new file. Instead of creating a new
+file, opening it up in my preferred editor, pasting all that text, and saving
+the file, I can run one small command from the CLI.
+
+```bash
+$ pbpaste > data.txt
+```
+
+This redirects the contents of `pbpaste` (which is the system clipboard) into
+the file `data.txt`. If that file doesn't already exist, then it will be
+created before the data is written to it.
+
+See `man pbpaste` for more details.

postgres/fetch-specific-number-of-results.md

@@ -0,0 +1,42 @@
+# Fetch Specific Number Of Results
+
+If you pull up just about any intro to PostgreSQL (or even SQL), one of the
+first things they are going to teach you is the `limit` clause. This is taught
+as _the_ way for limiting the result set to a specific number of rows.
+
+```sql
+> select title from books limit 4;
++-----------------------+
+| title                 |
+|-----------------------|
+| The Secret History    |
+| A Gentleman in Moscow |
+| Exhalation: Stores    |
+| Annihilation          |
++-----------------------+
+SELECT 4
+```
+
+You might be as surprised as I was to learn that `limit` is not part of the SQL
+standard. It is extremely common for this use case, but the SQL standard
+defines `fetch first N rows only` as the way to fetch a specific number of
+rows. As we can see, [it works identically to `limit
+N`](https://www.postgresql.org/docs/current/sql-select.html#SQL-LIMIT).
+
+```sql
+> select title from books fetch first 4 rows only;
++-----------------------+
+| title                 |
+|-----------------------|
+| The Secret History    |
+| A Gentleman in Moscow |
+| Exhalation: Stores    |
+| Annihilation          |
++-----------------------+
+SELECT 4
+```
+
+The `rows` and `row` keywords are interchangeable which makes statements more
+readable if, for instance, you're doing `... fetch first 1 row only`.
+
+[source](https://www.cybertec-postgresql.com/en/postgresql-limit-vs-fetch-first-rows-with-ties/)