///////////////////////////////////////////////////////////////
//                                                           //
//  top.cpp   -   send first few file lines to output        //
//                                                           //
//  version:      1.2                                        //
//  Language:     Borland C++, ver 5.0                       //
//  Platform:     Dell Pentium 200, Windows NT 4.0           //
//  Application:  CSE687 Example                             //
//  Author:       Jim Fawcett                                //
//                CST 2-187, (315) 443-3948                  //
//                fawcett@neptune.syr.edu                    //
///////////////////////////////////////////////////////////////
/*


    usage: top [-15] file1.hpp file2.cpp ..


*/
///////////////////////////////////////////////////////////////
//  Build Process                                            //
//  -------------                                            //
//  Files required:                                          //
//  top.cpp, strs.hpp, strs.cpp                              //
//                                                           //
//  build command:                                           //
//  cl /GX top.cpp strs.cpp /link setargv.obj                //
//                                                           //
///////////////////////////////////////////////////////////////
/*

    Maintenance History
    -------------------
      ver 1.2 : 24 Jan 99
        - replaced Borland build process with Visual C++ build
      ver 1.1 : 09 Jan 98
        - cosmetic modifications to this page
      ver 1.0 : 24 Dec 95
        - first release

*/

//

#include <fstream.h>   // ifstream(), >>, <<, cout
#include <stdlib.h>    // atoi()
#include "strs.h"      // string definitions


static int dispLines = 10;
  // default number of lines to display, has file scope, e.g.,
  // defined in static memory and globally visible in this file only

//----< display top few lines of file >------------------------

void showTop(char *fileName) {

// open file
  ifstream in(fileName);
  if(!in.good()) {
    cerr << "can't open file " << fileName << endl;
    return;
  }
// announce file name to output
  cout << fileName << endl;

// read dispLines strings from the top of input file
// and send to standard output

  static str s;   // static local variable defined in static
                  // memory, exists for program lifetime
                  // has internal character memory allocated
                  // on heap (see strs.cpp, strAlloc() function

  int j;          // local variable, defined on showTop's stack
                  // frame and is redefined for each invocation
  for(j=0; j<dispLines; j++) {
    in >> s;
    if(!in.good())
      break;
    cout << s << endl;
  }
  cout << endl;
}


//----< process commands and display files >-------------------

void main(int argc, char *argv[]) {

  int i;         // defined on main's stack frame
  for(i=1; i<argc; i++) {

    if(argv[i][0] == '-') {             // commands start with '-'
      dispLines = atoi(&argv[i][1]);
      continue;
    }
    else
      showTop(argv[i]);
  }
}