從命令列讀取一個檔案的檔名，輸出文字有多少個字元

#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
using namespace std;
int count_words(char *filename){
    int nb_of_chars = 0;
    char ch;
    ifstream inFile;
    inFile.open(filename);
    if(!inFile.is_open()){
        printf(
 
"%s cannot open\n", filename);
        exit(EXIT_FAILURE);
    }
    inFile >> noskipws;
    inFile >> ch;
    while(inFile.good()){
        nb_of_chars++;
        inFile >> ch;
    }
    return nb_of_chars;
}
int main(int args, char *argv[]){
    int res;
    res = count_words(argv[1
 
]);
    printf("%s\t%d\n", argv[1], res);
}

要注意的是C++的ifstream建立的inFile會預設跳過空白字元，因此noskipws是一個必要的引數