/* Filename:  readtext.cpp

   Author:  Br. David Carlson

   Date:  February 1, 1998

   Revised:  June 9, 1998

   Revised:  July 12, 2000 to use modern headers.

   This program prompts the user for the name of a text file to read.
   It then displays the file's contents on the screen.
*/

#include <iostream>
#include <fstream>   // needed for files
using namespace std;


const int MaxString = 120;

typedef char StringType[MaxString];


/* Given:  InStream     An input file stream already open for reading.
           StringMax    The maximum number of characters that can be put
                        into String, including the NULL that marks the
                        end of the string.
   Task:   To read up to StringMax - 1 characters from InStream, storing
           them in String, but stopping if a newline is read or end of
           file or an error condition is reached.
   Return: String       The string just read, with a NULL appended to
                        mark the end of the string.  If a newline was
                        read, it is not stored in String.
           The number of characters read into String (not counting the NULL)
           is returned in the function name.
*/
int MyGetLine(istream & InStream, char * String, int StringMax)
   {
   char Ch;
   int Count, Last;

   Count = 0;
   Last = StringMax - 1;
   Ch = InStream.get();

   while ((Ch != '\n') && (! InStream.fail()))
      {
      if (Count < Last)
         String[Count++] = Ch;
      Ch = InStream.get();
      }

   String[Count] = NULL;
   return Count;
   }


/* Given:   InFile   A file stream already opened for input.
   Assumes: That InFile is associated with a text file.
   Task:    To display on screen the contents of the file.
   Return:  InFile   The modified file stream.
*/
void DisplayFile(fstream & InFile)
   {
   StringType Line;
   int CharCount;
   int LineCount = 0;

   CharCount = MyGetLine(InFile, Line, MaxString);

   while ((CharCount > 0) || (! InFile.fail()))
      {
      cout << Line << endl;
      LineCount++;
      if (LineCount == 22)
         {
         LineCount = 0;
         cout << "   Press ENTER to go on...";
         cin.get();
         }
      CharCount = MyGetLine(InFile, Line, MaxString);
      }

   if (LineCount != 0)
      {
      cout << "   Press ENTER to go on...";
      cin.get();
      }
   }


int main(void)
   {
   StringType FileName;
   fstream InFile;

   cout << "Enter the name of the text file to be read: ";
   MyGetLine(cin, FileName, MaxString);

   InFile.open(FileName, ios::in);
   if (InFile.fail())
      {
      cerr << "Could not open file " << FileName << endl;
      exit(1);
      }

   DisplayFile(InFile);
   InFile.close();
   return 0;
   }