PracticeDev/study_cpp/cpp_primer_source_code/Chapter 17/count.cpp

40 lines
1.1 KiB
C++
Raw Normal View History

2022-12-20 17:31:11 +08:00
// count.cpp -- counting characters in a list of files
#include <iostream>
#include <fstream>
#include <cstdlib> // or stdlib.h
int main(int argc, char * argv[])
{
using namespace std;
if (argc == 1) // quit if no arguments
{
cerr << "Usage: " << argv[0] << " filename[s]\n";
exit(EXIT_FAILURE);
}
ifstream fin; // open stream
long count;
long total = 0;
char ch;
for (int file = 1; file < argc; file++)
{
fin.open(argv[file]); // connect stream to argv[file]
if (!fin.is_open())
{
cerr << "Could not open " << argv[file] << endl;
fin.clear();
continue;
}
count = 0;
while (fin.get(ch))
count++;
cout << count << " characters in " << argv[file] << endl;
total += count;
fin.clear(); // needed for some implementations
fin.close(); // disconnect file
}
cout << total << " characters in all files\n";
return 0;
}