Chapter 12: An I/O Project: Building a Command Line Program
Accepting Command Line Arguments
Reading the Argument Values
Saving the Argument Values in Variables
Reading a File
Refactoring to Improve Modularity and Error Handling
Separation of Concerns for Binary Projects
Fixing the Error Handling
Extracting Logic from main
Splitting Code into a Library Crate
Developing the Library’s Functionality with Test-Driven Development
Writing a Failing Test
Writing Code to Pass the Test
Working with Environment Variables
Writing a Failing Test for the Case-Insensitive Search Function
Implementing the search_case_insensitive Function
Writing Error Messages to Standard Error Instead of Standard Output
Checking Where Errors Are Written
Printing Errors to Standard Error