diff --git a/README.md b/README.md index 077b1c0..08d2dd7 100644 --- a/README.md +++ b/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). -_1334 TILs and counting..._ +_1335 TILs and counting..._ --- @@ -1322,6 +1322,7 @@ _1334 TILs and counting..._ - [Print Milliseconds In Human-Readable Format](unix/print-milliseconds-in-human-readable-format.md) - [Print Out Files In Reverse](unix/print-out-files-in-reverse.md) - [Print The Current Date In Human-Readable Format](unix/print-the-current-date-in-human-readable-format.md) +- [Produce A Lowercase V4 UUID](unix/produce-a-lowercase-v4-uuid.md) - [Provide A Fallback Value For Unset Parameter](unix/provide-a-fallback-value-for-unset-parameter.md) - [Remove A Directory Called `-p`](unix/remove-a-directory-called-dash-p.md) - [Repeat Yourself](unix/repeat-yourself.md) diff --git a/unix/produce-a-lowercase-v4-uuid.md b/unix/produce-a-lowercase-v4-uuid.md new file mode 100644 index 0000000..31a25a6 --- /dev/null +++ b/unix/produce-a-lowercase-v4-uuid.md @@ -0,0 +1,26 @@ +# Produce A Lowercase V4 UUID + +There are [a variety of ways to produce a v4 +UUID](different-ways-to-generate-a-v4-uuid.md) on Unix-based machines. Of the +options I listed in that post, my favorite is the `uuidgen` command. My only +gripe with it is that it produces an all uppercase UUID. + +```bash +$ uuidgen +B7918C26-12AE-4093-B6DA-0D7D41C59FB6 +``` + +Often when I need a UUID, it is to plug in as the ID value for some test data +in a system that is using lowercase UUIDs. For the sake of consistency, I'd +like it to be lowercase as well. + +The `tr` command comes in handy for this because I can _tr_anslate the +uppercase characters to lowercase ones. + +```bash +$ uuidgen | tr '[:upper:]' '[:lower:]' +ed817cf3-8f70-4838-82bc-8e5b328c0b93 +``` + +So now anytime I need a lowercase UUID, I hit `ctrl-r` and search back for +either `uuid` or `lower` and find this command pretty quickly.