Basic Parsing using strtok

 

C string.h library provides functionalities for parsing like strtok()

string tokenizer is a functionality which will tokenize the string using the delimiter
It basically replaces the delimiter string(char *) with '\0'
next time we do strtok we give NULL as input instead of char* token with delimiter string. 

char *strtok(char *token, char* delimiter); 

Usage of strtok in Computer Networks for IP Address Parsing

#include <string.h>

#include <stdio.h>

#include <stdlib.h>

int main()

{

  int val;

  char c[64]="192.168.0.0";  // be careful it should be character array not character pointer

  char *tok;

  tok=strtok(c,".");

  while(tok != NULL)

  {

     val = atoi(tok);

     printf("%s %d %x %o\n",tok,val,val,val);

     tok=strtok(NULL,".");

  }

}

 

Wide application of strtok can be used for questions like:-

"I LOVE MY COUNTRY"

"COUNTRY MY LOVE I"

 

#include <bits/stdc++.h>
#include <iostream>
#include <string>
#include <cstring>
using namespace std;

void PrintReverse( stack<string> st)
{
     while(!st.empty())
    {
         string temp = st.top();
         cout << temp << " ";
        st.pop();
    }
}

int main()
{
   stack<string> st;
   char c[] = "I LOVE MY COUNTRY";
   char *tok = strtok(c," ");
   while(tok != NULL)
   {
       string str = string(tok);
       st.push(str);
       tok = strtok(NULL, " ");
    }
      PrintReverse(st);
  return 0;
}