Re: Printing non-printable characters

From:

Saeed Amrollahi <amrollahi.saeed@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 18 May 2011 03:20:04 -0700 (PDT)

Message-ID:

<2362521c-1a5a-4df8-99c9-9341fa22079f@p13g2000yqh.googlegroups.com>

On May 18, 10:55 am, Alex Vinokur <alex.vino...@gmail.com> wrote:

Hi,

// --------------------
#include <iostream>
#include <iomanip>

int main()
{
        char data[5];
  data[0] = 'a';
  data[1] = 5;
  data[2] = 'b';
  data[3] = 10;
  data[4] = 0;

  for (std::size_t i = 0; i < sizeof(data); i++)
  {
        char ch = data[i];

        if (isprint(static_cast<int>(ch)) != 0)
        {
                        std::cout << ch;
                }
                else
        {
                std::cout << "\\" << std::oct << static_c=

ast<int>(ch) << std::dec;

    }
  }
  std::cout << std::endl;

  return 0;

}

// ------------------

Output:
a\5b\12\0

Is it possible to get the same or similar output without loop in the
program?

Thanks,

Alex

Hi Alex
One typical solution is, to define a
function object and wrap the if-else statement in
overloaded function call operator, then use for_each
algorithm instead of for loop. Something like this:

#include <algorithm>
#include <iostream>
#include <iomanip>

struct Send2Output {
  std::ostream& os;
  Send2Output() : os(std::cout) {}
  void operator()(const char ch)
  {
    if (isprint(static_cast<int>(ch)) != 0)
      os << ch;
    else
      os << "\\" << std::oct << static_cast<int>(ch) << std::dec;
  }
};

int main()
{
  using namespace std;
  char data[5] = { 'a', 5, 'b', 10, 0 };
  Send2Output S2O;
  for_each(data, data + 5, S2O);
  return 0;
}

HTH
  -- Saeed Amrollahi