Why I am getting same string out put?

Question

I am not able to get the expected output for below function.

in.txt file

-rw-r--r--  1 air  staff  StructEx.cpp
-rw-r--r--  1 air  staff  Struct2ex.cpp
drwxr-xr-x  3 air  staff  app.dSYM
-rw-r--r--  1 air  staff  MyStruct.cpp

excepted - to print column 1 and column 4 contents from the above in.txt file. some thing like below

-rw-r--r--StructEx.cpp
-rw-r--r--Struct2ex.cpp
drwxr-xr-xapp.dSYM
-rw-r--r--MyStruct.cpp

actual output -

-rw-r--r--tructEx.cpp
-rw-r--r--tructEx.cpp
-rw-r--r--tructEx.cpp
-rw-r--r--tructEx.cpp

the above output is wrong, what I am missing in below string stream function.

  void readingFromFile2(){

      ifstream inputFile("in.txt");
      string line;
      stringstream entireLine;
      char s = ' ';
        string p1, p2, p3, p4, p5;

      while(!inputFile.fail()){
        getline(inputFile, line);
        entireLine << line;
        entireLine >> p1 >> s >> p2 >> s >> p3 >> s >> p4 >> s >> p5 ;
        cout << p1 << p4 << endl ;
      }

    }

edit from important comments, I think below function makes more sense, but still the same out put

void readingFromFile2(){

  ifstream inputFile("in.txt");
  string line;
  stringstream entireLine;
  char s = ' ';
    string p1, p2, p3, p4, p5;
    char n ='\n';

  while(getline(inputFile, line)){
    entireLine << line;
    entireLine >> p1  >> p2  >> p3  >> p4  >> p5 ;
    cout << p1 <<  p4  << endl ;
  }
}

Update - entire code

#include <iostream>
#include <fstream>
#include <sstream>

using namespace std;

void readingFromFile2();

int main(){
  readingFromFile2();
}

void readingFromFile2(){

  ifstream inputFile("in.txt");
  string line;
  stringstream entireLine;
  string p1, p2, p3, p4, p5;
  while(getline(inputFile, line)){
    entireLine << line;
    entireLine >> p1  >> p2  >> p3  >> p4  >> p5 ;
    cout << p1 << p2 << p3 << p3 << p4 << p5 << endl ;
  }
}

Now it is working, use stringstream entireLine(line); instead of entireLine << line;

Answer 1

While using >> for stream input you should use

  entireLine >> p1 >> p2 >> p3 >> p4 >> p5 ;

because spaces (' ', \t and \n) are ignored.

UPDATE:

Why "-rw-r--r-- 1 air staff StructEx.cpp" gives tructEx.cpp instead of staff when entireLine >> p1 >> s >> p2 >> s >> p3 >> s >> p4 >> s >> p5 ; is used?

Let's look step by step:

1) entireLine >> p1

string till the first space is read to p1: -rw-r--r-- goes to p1

2) entireLine >> s

skips the space and 1 goes to s

3) entireLine >> p2

skips the space and air goes to p2

4) entireLine >> s

skips the space and s (beginning of staff) goes to s

5) entireLine >> p3

just reads taff to p3

6) entireLine >> s

skips the space and S (beginning of StructEx.cpp) goes to s

7) entireLine >> p4

eventually we have value for p4 and this is tructEx.cpp, because S was taken at step 6) to s

UPDATE 2

Simplified demo:

#include <iostream>
#include <string>
#include <sstream>

using namespace std;

int main() {
    string line = "-rw-r--r--  1 air  staff  StructEx.cpp";
    stringstream entireLine;
    char s = ' '; // not required
    string p1, p2, p3, p4, p5;
    char n = '\n'; // not required

    entireLine << line;
    entireLine >> p1 >> p2 >> p3 >> p4 >> p5;
    cout << p1 << ", " << p2 << ", " << p3 << ", " << p4 << ", " << p5 << endl;

    return 0;
}

gives

But

#include <iostream>
#include <string>
#include <sstream>

using namespace std;

int main() {
    string line = "-rw-r--r--  1 air  staff  StructEx.cpp";
    stringstream entireLine;
    char s = ' '; // initialization has no sense
    string p1, p2, p3, p4, p5;
    char n = '\n'; // not required

    entireLine << line;
    entireLine >> p1 >> s >> p2 >> s >> p3 >> s >> p4 >> s >> p5; // HERE!!!
    cout << p1 << ", " << p2 << ", " << p3 << ", " << p4 << ", " << p5 << endl;

    return 0;
}

produces

FINAL UPDATE

void readingFromFile2(){

    ifstream inputFile("in.txt");
    string line;
    //stringstream entireLine;
    string p1, p2, p3, p4, p5;
    char str[51];
    while (getline(inputFile, line)){
        stringstream entireLine(line); //entireLine << line;
        entireLine >> p1 >> p2 >> p3 >> p4 >> p5;
        cout << p1 << p4 << endl;
    }
}