In Bash, you can check if a file exists using the test command or the equivalent [ command. The most common way to check if a file does not exist is by using the -e option, which tests whether a file exists. To check if a file does not exist, you can negate this option using !

In Bash, you can use the IFS (Internal Field Separator) variable to specify the delimiter and the read command to split a string into tokens based on that delimiter.

A package.json file must contain Name and Versoin fields inside the json. The name field consists with package's name, and must be in lowercase and one word and may contain hyphens and underscores. The version field must be in x.x.x and and see the guidelines below,

By default the Python language providers in-built function to display alphabets letters. You can see the code here,

First, we have to understand what is the Fibonacci sequence, which forms a sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1.

The Carriage Return character is \r (0x0D), the CR character moves the cursor to the beginning of the line without advancing to the next line.

In this post how to replace and remove one or more lines in a file using sed command with example.