logging.php is a simple command-line program to demonstrate writing to a log, listing its entries, deleting it, interacting with sinks to export logs to Google Cloud Storage.

To use logging sinks, you will also need a Google Cloud Storage Bucket.

gsutil mb gs://[YOUR_PROJECT_ID]

You must add Cloud Logging as an owner to the bucket. To do so, add cloud-logs@google.com as an owner to the bucket. See the exportings logs docs for complete details.

Use the Cloud SDK to provide authentication:

gcloud beta auth application-default login

Run the samples:

```
php logging.php list # For getting sub command list
php logging.php help write # For showing help for write sub command `write`
```