一般来说，创建一个类，
会想到库
类的声明在头文件 .h中定义
类的成员函数的实现 在 .cpp中建立
文件有特殊的要求
一个特殊的编码标准
头文件的预处理语句避免类的重复声明
//: C04:Cppcheck.cpp
// From "Thinking in C++, Volume 2", by Bruce Eckel & Chuck Allison.
// (c) 1995-2004 MindView, Inc. All Rights Reserved.
// See source code use permissions stated in the file 'License.txt',
// distributed with the code package available at www.MindView.net.
// Configures .h & .cpp files to conform to style
// standard. Tests existing files for conformance.
#include <fstream>
#include <sstream>
#include <string>
#include <cstddef>
#include "../require.h"
using namespace std;
bool startsWith(const string& base, const string& key) {
return base.compare(0, key.size(), key) == 0;
}
void cppCheck(string fileName) {
enum bufs { BASE, HEADER, IMPLEMENT, HLINE1, GUARD1,
GUARD2, GUARD3, CPPLINE1, INCLUDE, BUFNUM };
string part[BUFNUM];
part[BASE] = fileName;
// Find any '.' in the string:
size_t loc = part[BASE].find('.');
if(loc != string::npos)
part[BASE].erase(loc); // Strip extension
// Force to upper case:
for(size_t i = 0; i < part[BASE].size(); i++)
part[BASE][i] = toupper(part[BASE][i]);
// Create file names and internal lines:
part[HEADER] = part[BASE] + ".h";
part[IMPLEMENT] = part[BASE] + ".cpp";
part[HLINE1] = "//" ": " + part[HEADER];
part[GUARD1] = "#ifndef " + part[BASE] + "_H";
part[GUARD2] = "#define " + part[BASE] + "_H";
part[GUARD3] = "#endif // " + part[BASE] +"_H";
part[CPPLINE1] = string("//") + ": " + part[IMPLEMENT];
part[INCLUDE] = "#include \"" + part[HEADER] + "\"";
// First, try to open existing files:
ifstream existh(part[HEADER].c_str()),
existcpp(part[IMPLEMENT].c_str());
if(!existh) { // Doesn't exist; create it
ofstream newheader(part[HEADER].c_str());
assure(newheader, part[HEADER].c_str());
newheader << part[HLINE1] << endl
<< part[GUARD1] << endl
<< part[GUARD2] << endl << endl
<< part[GUARD3] << endl;
} else { // Already exists; verify it
stringstream hfile; // Write & read
ostringstream newheader; // Write
hfile << existh.rdbuf();
// Check that first three lines conform:
bool changed = false;
string s;
hfile.seekg(0);
getline(hfile, s);
bool lineUsed = false;
// The call to good() is for Microsoft (later too):
for(int line = HLINE1; hfile.good() && line <= GUARD2;
++line) {
if(startsWith(s, part[line])) {
newheader << s << endl;
lineUsed = true;
if(getline(hfile, s))
lineUsed = false;
} else {
newheader << part[line] << endl;
changed = true;
lineUsed = false;
}
}
// Copy rest of file
if(!lineUsed)
newheader << s << endl;
newheader << hfile.rdbuf();
// Check for GUARD3
string head = hfile.str();
if(head.find(part[GUARD3]) == string::npos) {
newheader << part[GUARD3] << endl;
changed = true;
}
// If there were changes, overwrite file:
if(changed) {
existh.close();
ofstream newH(part[HEADER].c_str());
assure(newH, part[HEADER].c_str());
newH << "//@//\n" // Change marker
<< newheader.str();
}
}
if(!existcpp) { // Create cpp file
ofstream newcpp(part[IMPLEMENT].c_str());
assure(newcpp, part[IMPLEMENT].c_str());
newcpp << part[CPPLINE1] << endl
<< part[INCLUDE] << endl;
} else { // Already exists; verify it
stringstream cppfile;
ostringstream newcpp;
cppfile << existcpp.rdbuf();
// Check that first two lines conform:
bool changed = false;
string s;
cppfile.seekg(0);
getline(cppfile, s);
bool lineUsed = false;
for(int line = CPPLINE1;
cppfile.good() && line <= INCLUDE; ++line) {
if(startsWith(s, part[line])) {
newcpp << s << endl;
lineUsed = true;
if(getline(cppfile, s))
lineUsed = false;
} else {
newcpp << part[line] << endl;
changed = true;
lineUsed = false;
}
}
// Copy rest of file
if(!lineUsed)
newcpp << s << endl;
newcpp << cppfile.rdbuf();
// If there were changes, overwrite file:
if(changed) {
existcpp.close();
ofstream newCPP(part[IMPLEMENT].c_str());
assure(newCPP, part[IMPLEMENT].c_str());
newCPP << "//@//\n" // Change marker
<< newcpp.str();
}
}
}
int main(int argc, char* argv[]) {
if(argc > 1)
cppCheck(argv[1]);
else
cppCheck("cppCheckTest.h");
getchar();
} ///:~有用的函数startsWith()
这个函数的名字说明了它的功能
如果函数的第1个字符串参数的内容以第2个字符串参数的内容开始
即第2个参数为第1个参数的前缀
返回true如果程序不带参数
会创建下面两个文件
//: CPPCHECKTEST.h
#ifndef CPPCHECKTEST_H
#define CPPCHECKTEST_H
#endif // CPPCHECKTEST_H
//: CPPCHECKTEST.cpp
#include "CPPCHECKTEST.h"删掉第一行 CPPCHECKTEST.h CPPCHECKTEST.cpp
//@//
//: CPPCHECKTEST.h
#ifndef CPPCHECKTEST_H
#define CPPCHECKTEST_H
#ifndef CPPCHECKTEST_H
#define CPPCHECKTEST_H
#endif // CPPCHECKTEST_H//@//
//: CPPCHECKTEST.cpp
#include "CPPCHECKTEST.h"
#include "CPPCHECKTEST.h"在文件中删除行重新执行程序
可以对程序完成的功能测试
看到每次执行程序后被删除的行会被写回文件
文件被修改后，在文件的第1行会加入字符串
让读者注意文件的变化