A programoz¢ ‚let£tja

Az al bbi p‚ld kon nyomon k”vethetjk a programoz¢ szakmai fejl“d‚s‚nek
 llom sait. L ssuk teh t, hogyan k‚sz”ti el a klasszikus "Hello Word"
programot, ‚let‚nek kl”nb”z“ szakaszaiban:

Gimnazista

     10 PRINT "HELLO WORLD"
     20 END

Els“s egyetemista

     program Hello(input, output)
       begin
         writeln('Hello World')
       end.

Utols¢‚ves egyetemista

     (defun hello
       (print
         (cons 'Hello (list 'World))))

Kezd“ profi

     #include <stdio.h>
     void main(void)
     { char *message[] = {"Hello ", "World"};
       int i;
        for(i = 0; i< 2; ++i)
        printf("%s", message[i]);
        printf("\n");
  }

Rafin lt profi

     #include <iostream.h>
     #include <string.h>

      class string
      {
      private:
        int size;
        char *ptr;

      public:
        string() : size(0), ptr(new char('\0')) {}

        string(const string &s) : size(s.size)
        {
          ptr = new char[size + 1];
          strcpy(ptr, s.ptr);
        }

        ~string()
        {
          delete [] ptr;
        }

        friend ostream &operator <<(ostream &, const string &);
        string &operator=(const char *);
      };

      ostream &operator<<(ostream &stream, const string &s)
      {
        return(stream << s.ptr);
      }

      string &string::operator=(const char *chrs)
      {
        if (this != &chrs)
        {
          delete [] ptr;
         size = strlen(chrs);
          ptr = new char[size + 1];
          strcpy(ptr, chrs);
        }
        return(*this);
      }

      int main()
      {
        string str;

        str = "Hello World";
        cout << str << endl;

        return(0);
      }

Mesterprogramoz¢

      [
      uuid(2573F8F4-CFEE-101A-9A9F-00AA00342820)
      ]
      library LHello
      {
          // bring in the master library
          importlib("actimp.tlb");
          importlib("actexp.tlb");

          // bring in my interfaces
          #include "pshlo.idl"

          [
          uuid(2573F8F5-CFEE-101A-9A9F-00AA00342820)
          ]
          cotype THello
       {
       interface IHello;
       interface IPersistFile;
       };
      };

      [
      exe,
      uuid(2573F890-CFEE-101A-9A9F-00AA00342820)
      ]
      module CHelloLib
      {

          // some code related header files
          importheader(
Kezd“ buher tor

    #!/usr/local/bin/perl
      $msg="Hello, world.\n";
      if ($#ARGV = 0) {
        while(defined($arg=shift(@ARGV))) {
          $outfilename = $arg;
          open(FILE, "" . $outfilename) ³³ die "Can't write $arg: $!\n";
          print (FILE $msg);
          close(FILE) ³³ die "Can't close $arg: $!\n";
        }
      } else {
        print ($msg);
      }
      1;

Tapasztalt buher tor


      #include

Rafin lt buher tor

     % cc -o a.out ~/src/misc/hw/hw.c
     % a.out

Nagymester buher tor

     % cat
       Hello, world.
       ^D

Ujdonslt menedzser

     10 PRINT "HELLO WORLD"
     20 END

K”z‚pvezet“ menedzser

     mail -s "Hello, world." bob@b12
     Bob, tudnal nekem holnapra irni egy programot,
     ami kiirja a kepernyore, hogy "Hello word"?
     Koszi!
     ^D

Vezet“ menedzser

     % zmail jim
       Delutanra szuksegem van egy "Hello Word" programra.

Vez‚rigazgat¢

% letter
  letter: Command not found.
% mail To: ^X
^F ^C
% help mail
help: Command not found.
% faszom!
!: Event unrecognized
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