exercise 8.13.14

ch08/ex8.13.14/data/record.txt

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+morgan 2015552368 8625550123
+drew   9735550130
+lee    6095550132 2015550175 8005550000

ch08/ex8.13.14/main.cpp

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+/***************************************************************************
+*  @file       main.cpp
+*  @author     Queequeg
+*  @date       26  Nov 2014
+*  @remark     This code is for the exercises from C++ Primer 5th Edition
+*  @note
+***************************************************************************/
+//!
+//! Exercise 8.13
+//! Rewrite the phone number program from this section to read from a named 
+//! file rather than from cin.
+
+//!
+//! Exercise 8.14
+//! Why did we declare entry and nums as const auto &?
+//! We don't expect to modify the original data.
+
+#include<iostream>
+using std::cerr;
+using std::cout;
+using std::cin;
+using std::endl;
+using std::istream;
+using std::ostream;
+
+#include<fstream>
+using std::ifstream;
+using std::ofstream;
+
+#include<sstream>
+using std::istringstream;
+using std::ostringstream;
+
+#include<string>
+using std::string;
+
+#include<vector>
+using std::vector;
+
+struct PersonInfo {
+	string name;
+	vector<string> phones;
+};
+
+bool read_record(istream& is, vector<PersonInfo>& people);
+void format_record(ostream& os, const vector<PersonInfo>& people);
+
+//! fake functions that make the program compile
+bool valid(const string &num){ return true; }
+string format(const string &num){ return num; }
+
+int main()
+{
+	vector<PersonInfo> people;
+
+	string filename;
+	cout << "Please input a record file name: ";
+	cin >> filename;
+	cout << endl;
+	ifstream fin(filename);
+
+	if (read_record(fin, people))
+	{
+		ofstream fout("data\\result.txt", ofstream::trunc);
+		format_record(fout, people);
+	}
+	else
+	{
+		cout << "Fail to open file " << filename << endl;
+	}
+
+	return 0;
+}
+
+bool read_record(istream& is, vector<PersonInfo>& people)
+{
+	if (is)
+	{
+		string line, word; // will hold a line and word from input, respectively
+		// read the input a line at a time until cin hits end-of-file (or another error)
+		while (getline(is, line))
+		{
+			PersonInfo info; // create an object to hold this record's data
+			istringstream record(line); // bind record to the line we just read
+			record >> info.name; // read the name
+			while (record >> word) // read the phone numbers
+				info.phones.push_back(word); // and store them
+			people.push_back(info); // append this record to people
+		}
+		return true;
+	}
+	else
+		return false;
+}
+
+void format_record(ostream& os, const vector<PersonInfo>& people)
+{
+	for (const auto &entry : people) 
+	{
+		// for each entry in people
+		ostringstream formatted, badNums; // objects created on each loop
+		for (const auto &nums : entry.phones) 
+		{
+			// for each number
+			if (!valid(nums)) 
+			{
+				badNums << " " << nums; // string in badNums
+			}
+			else
+				// "writes" to formatted's string
+				formatted << " " << format(nums);
+		}
+		if (badNums.str().empty()) // there were no bad numbers
+			os << entry.name << " " // print the name
+			   << formatted.str() << endl; // and reformatted numbers
+		else // otherwise, print the name and bad numbers
+			cerr << "input error: " << entry.name
+			     << " invalid number(s) " << badNums.str() << endl;
+	}
+}