读取文本文件

#include <iostream>
#include <stdlib.h>
#include <unistd.h>
#include <fstream>

using namespace std;

void dofile(char *filename)
{
    FILE *f;long len;char *data;

    f=fopen(filename,"rb");
    fseek(f,0,SEEK_END);
    len=ftell(f);
    fseek(f,0,SEEK_SET);
    data=(char*)malloc(len+1);
    fread(data,1,len,f);
    fclose(f);

    cout << data << endl;
    free(data);
}

void dofile2(char *filename)
{
    ifstream input(filename);
    if(!input){
        cout << "open file error" << endl;
    }
#if 1
    string s;
    string str;
    while(input >> s)
        str += s;

    cout << str << endl;
#else
    char buf[1024];
    char c;
    int n = 0;
    while(input >> c){
        sprintf(buf+n,"%c",c);
        ++n;
    }

    cout << buf << endl;
#endif
}

int main()
{
    cout << "Hello World!" << endl;


//    dofile("./test1.txt");
//    dofile2("./test1.txt");

//    dofile("./test2.json");
//    dofile2("./test2.json");
//    dofile2("./test3.json");
    dofile2("./test4");



    return 0;
}