从输入文件逐行输入,并使用strtok()和输出到输出文件中进行tokenize
问题描述:
我想做的是输入一个文件LINE BY LINE和tokenize并输出到一个输出文件。我已经能够做的是输入文件的第一行,但我的问题是,我不能输入下一行tokenize,以便它可以保存为输出文件中的第二行,这是我可以做的输入文件中的第一行。
What I am trying to do is to input a file LINE BY LINE and tokenize and output into an output file.What I have been able to do is input the first line in the file but my problem is that i am unable to input the next line to tokenize so that it could be saved as a second line in the output file,this is what i could do so far fro inputing the first line in the file.
#include <iostream>
#include<string> //string library
#include<fstream> //I/O stream input and output library
using namespace std;
const int MAX=300; //intialization a constant called MAX for line length
int main()
{
ifstream in; //delcraing instream
ofstream out; //declaring outstream
char oneline[MAX]; //declaring character called oneline with a length MAX
in.open("infile.txt"); //open instream
out.open("outfile.txt"); //opens outstream
while(in)
{
in.getline(oneline,MAX); //get first line in instream
char *ptr; //Declaring a character pointer
ptr = strtok(oneline," ,");
//pointer scans first token in line and removes any delimiters
while(ptr!=NULL)
{
out<<ptr<<" "; //outputs file into copy file
ptr=strtok(NULL," ,");
//pointer moves to second token after first scan is over
}
}
in.close(); //closes in file
out.close(); //closes out file
return 0;
}
答
C++ String Toolkit Library(StrTk)对您的问题有以下解决方案:
The C++ String Toolkit Library (StrTk) has the following solution to your problem:
#include <iostream>
#include <string>
#include <deque>
#include "strtk.hpp"
int main()
{
std::deque<std::string> word_list;
strtk::for_each_line("data.txt",
[&word_list](const std::string& line)
{
const std::string delimiters = "\t\r\n ,,.;:'\""
"!@#$%^&*_-=+`~/\\"
"()[]{}<>";
strtk::parse(line,delimiters,word_list);
});
std::cout << strtk::join(" ",word_list) << std::endl;
return 0;
}
更多示例请参见此处