Programming and Graphics

142 Introduction to C++ Programming and Graphics

Print a file

In a more advanced application, we generate a binary executable named
pfilethat displays the content of a file with a specified namefilenamein response
to the command:

pfile filenme

This is accomplished by the following code contained in the filepfile.cc:

#include <fstream>

#include <iostream>

using namespace std;

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

{

ifstream dev1(argv[1])

if(dev1.isopen() )

{

char x;

while (dev1.get(x))

cout<< x;

}

else

{

cout<<"Unable to open the file" << endl;

}

return 0;

}

The Boolean variabledev1.get(x)is false if the end of the filedev1has been
reached, and true otherwise.

Problems

5.4.1.Add to the programpfile.cca check that issues a warning if no file name,
or more than one file name, is specified.

5.4.2.Write an application that concatenates two files – that is, it creates a
new file consisting of the union of two input files.

5.5 Pointers to functions.........................

Pointers to user-defined functions are employed to concisely represent the func-
tions. Like pointers of regular data types, function pointers can be included in
the arguments of functions to give compound functions.