字符串问题
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <string>
using namespace std;
int main (int argc, char* argv[])
{
string filename, basename, extname, tmpname;
const string suffix("tmp");
/* for each command-line argument
* (which is an ordinary C-string)
*/
for (int i=1; i<argc; ++i) {
// process argument as file name
filename = argv[i];
// search period in file name
string::size_type idx = filename.find('.');
if (idx == string::npos) {
// file name does not contain any period
tmpname = filename + '.' + suffix;
}
else {
/* split file name into base name and extension
* - base name contains all characters before the period
* - extension contains all characters after the period
*/
basename = filename.substr(0, idx);
extname = filename.substr(idx+1);
if (extname.empty()) {
// contains period but no extension: append tmp
tmpname = filename;
tmpname += suffix;
}
else if (extname == suffix) {
// replace extension tmp with xxx
tmpname = filename;
tmpname.replace (idx+1, extname.size(), "xxx");
}
else {
// replace any extension with tmp
tmpname = filename;
tmpname.replace (idx+1, string::npos, suffix);
}
}
// print file name and temporary name
cout << filename << " => " << tmpname << endl;
}
}
这是c++ standard library 中字符串的第一个例子，我不明白main传的两个参数是用来做什么的？
后面的char* 因该是指向输入字符串的，前面的int是用来干吗的呢？
请教各位高手
