`simpio.h`

This file exports a set of functions that simplify input/output operations in C++ and provide some error-checking on user input.

Functions
getInteger(`prompt`)	Reads a complete line from user input and scans it as an integer.
getLine(`prompt`)	Reads a line of text from user input and returns that line as a string.
getReal(`prompt`)	Reads a complete line from user input and scans it as a floating-point number.
getYesOrNo(`prompt`)	Reads a complete line from user input and treats it as a yes-or-no answer to a question, returning a boolean value of `true` for yes and `false` for no.
promptUserForFilename(`prompt`)	Prompts user to enter the name of a file and returns it.

Function detail

int getInteger(string prompt = "", string reprompt = "");

Reads a complete line from user input and scans it as an integer. If supplied, the optional prompt string is printed before reading the value.

If the scan succeeds, the integer value is returned. If the argument is not a legal integer or if extraneous characters (other than whitespace) appear in the string, the user is given a chance to reenter the value. The optional reprompt message is displayed before asking the user to reenter an illegal value. If no reprompt argument is given, the message defaults to "Illegal integer format. Try again.".

Usage:

int age = getInteger("Please enter your age:");

double getReal(string prompt = "", string reprompt = "");

Reads a complete line from user input and scans it as a floating-point number. If supplied, the optional prompt string is printed before reading the value.

If the scan succeeds, the floating-point value is returned. If the input is not a legal number or if extraneous characters (other than whitespace) appear in the string, the user is given a chance to reenter the value. The optional reprompt message is displayed before asking the user to reenter an illegal value. If no reprompt argument is given, the message defaults to "Illegal numeric format. Try again.".

Usage:

double price = getReal("Enter the item price:");

string getLine(string prompt = "");

Reads a line of text from user input and returns that line as a string. The newline character that terminates the input is not stored as part of the return value. If the user only enters a newline, the return value is the empty string. If supplied, the optional prompt string is printed before reading the value.

Usage:

string line = getLine("What is your name?");

bool getYesOrNo(string prompt = "", string reprompt = "");

Reads a complete line from user input and treats it as a yes-or-no answer to a question. Returns true if the line typed begins with a 'y' or 'Y', and returns false if it begins with a 'n' or 'N'. If supplied, the optional prompt string is printed before reading the value.

If the user's input is not a valid Y or N response, they are asked to reenter. The optional reprompt message is displayed before asking the user to reenter an illegal value. If no reprompt argument is given, the message defaults to "Please type a word that starts with 'Y' or 'N'.".

Usage:

if (getYesOrNo("Do you want to play another round?")) { ...

string promptUserForFilename(string prompt = "", string reprompt = "");

Prompts the user to enter the name of a file, reads a complete line from user input and treats it as filename. If the named file does not exist, the user is given additional chances to enter a valid file name.

The optional prompt argument provides an input prompt for the user.

The also optional reprompt argument provides an output message displayed each time if the user types a file that is not found. If no value is passed it defaults to, "Unable to open that file. Try again.".

Usage:

string filename = promptUserForFilename("Enter a filename: ");