Temperature converter – Software Engineering

Exercise: Temperature converter

Build a temperature converter CLI tool in Go using structs and pointers

Objective:

Create a command-line interface (CLI) tool in Go that converts temperatures between Celsius and Fahrenheit. The idea is to build a tool that can be embedded as a call in a script or similar. See the example outputs below.

Try and use structs and pointers to acomplish this.

Requirements:

Use a Temperature struct
- Create a Temperature struct that contains:
  - A Value field representing the numerical temperature.
  - A Unit field representing the unit of the temperature ("C" for Celsius or "F" for Fahrenheit).
Implement conversion functions using pointers
- Write two functions:
  - celsiusToFahrenheit
  - fahrenheitToCelsius
- Each function should:
  - Accept a pointer to a Temperature struct.
  - Perform the appropriate conversion using the temperature value from the given struct.
  - Return a pointer to a new Temperature struct containing the converted temperature value and the new unit.
Accept arguments from command-line
- The program should accept two command-line arguments when executed:
  - The temperature value (e.g., "100")
  - The unit of the temperature ("C" or "F")
- Example usage:
```
<binary> 230 F
```
  The <binary> placeholder represents the name of the compiled binary file.
Perform conversion based on input
- In the main function, create a pointer to a Temperature struct using the input arguments.
- Determine the unit provided and call the appropriate conversion function.
  
  Hint: Consider which control structure could be used to determine this.
- Output the converted temperature value and unit to the console.
- Format the output to display the temperature value without decimal places.
  
  Hint: Use fmt.Printf with format specifiers to control the number type and number of decimal places displayed.
- Example output:
```
110 C
```

Expected outputs:

We use tempconverter as an example for the binary and $ indicates the command prompt.

Converting Fahrenheit to Celsius:
```
$ tempconverter 230 F
110 C
```
Converting Celsius to Fahrenheit:
```
$ tempconverter 100 C
212 F
```

Hints

Use the os package to access command-line arguments.
os.Args[0] // binary name
os.Args[1] // first argument
os.Args[2] // second argument

Use the strconv package to convert string arguments to numerical values. Like for example converting a string to a float64.
value, err := strconv.ParseFloat(os.Args[1], 64)

Force an exit if an error occurs with the os.Exit function. You can also use panic, but os.Exit is more appropriate for CLI tools.
os.Exit(1)

Extra (optional) — Implement additional error handling

Handle invalid input of value.

$ tempconverter abc F
Invalid temperature value. Please enter a numeric value.

Handle invalid input of unit.

$ tempconverter 100 K
Invalid unit. Please provide 'C' for Celsius or 'F' for Fahrenheit.

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