In Linux, single quotes ('), double quotes ("), and backquotes (`) serve different purposes. The easiest way to understand their differences is by using the DATE variable, the "date" string, and the date command.
Important:
' ... Single quotes
" ... Double quotes
In macOS Sonoma, a new method has been introduced to enable Touch ID when running sudo commands, making it more persistent across system updates. Previously, editing the /etc/pam.d/sudo file was necessary, but these changes would often revert after an update, requiring reconfiguration. With Sonoma, the settings can be added to a separate file /etc/pam.d/sudo_local, which isn't overwritten during updates, allowing Touch ID to remain enabled for sudo commands consistently.
In YAML, the | and > characters are used to denote different styles of multi-line strings. Here's a brief explanation of each:
The | character is used to preserve the exact formatting of the multi-line string, including line breaks and leading spaces. It's useful when you want to maintain the formatting of the text exactly as it is.
Example:
example_literal: |
This is a literal block scalar.
It preserves line breaks and
This Gist demonstrates how to use the aws-sdk-go package to upload and download objects from AWS S3 using Go. It utilizes the s3manager package to simplify these operations.
Before running the code, install the AWS SDK for Go using the following command:
$ go get github.com/aws/aws-sdk-go
This Gist demonstrates how to gzip compress and decompress files using the compress/gzip package in Go.
This Go program compresses a file named hello.txt into a gzip file named hello.txt.gz using the best compression level available.
package main
This guide introduces how to use AWS Lambda to retrieve data from DynamoDB. The data acquisition flow is as follows: API Gateway → Lambda → DynamoDB. This example focuses on the Lambda to DynamoDB part, omitting the details of invoking Lambda from the screen.
Here is an example of retrieving data using userId as a condition.
const { DynamoDBClient } = require('@aws-sdk/client-dynamodb');
You can use the describe-table command to easily get an approximation of the number of items from the metadata of a DynamoDB table. This saves time and money because you don't have to scan the entire table.
aws dynamodb describe-table --table-name TableName --profile ProfileName --region RegionName
In this short note, we'll explore various techniques to achieve concurrency in shell scripts. Concurrency allows for executing multiple operations in parallel, which can dramatically reduce the processing time by handling tasks simultaneously. We'll cover several methods, from basic background execution to more sophisticated tools like GNU Parallel.
Concurrency in shell scripting is facilitated by executing multiple processes simultaneously. This parallel processing allows a script to initiate subsequent tasks without waiting for the previous tasks to complete.
When using LIMIT in DynamoDB queries, the order of evaluation can differ from SQL queries, potentially leading to unexpected results depending on the search criteria used.
SQL queries follow a specific order of evaluation:
FROM -> ON -> JOIN -> WHERE -> GROUP BY -> HAVING -> SELECT -> DISTINCT -> ORDER BY -> LIMIT