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i want the user to enter an input without obligating him to press enter

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i want the user to enter an input without obligating him to press enter

 
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  #1
May 30th, 2004
hi , i am doing a project with c++ visual studio 6 and i really want this facility, which is ..
the user will enter a single character or a an integer ,so the compiler will take the input he entered (int or char) without waiting from him to press enter.
i need this facility to make the user browse between pages in my project, so he can use the cursor (" the numbers at right of the keybord")
plzz answer me today
the last day to give our dr the project is tommorow

thnx
bye
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Re: i want the user to enter an input outhout obligating him to press enter

 
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May 30th, 2004
getch(), mvgetch(), mvwgetch(), ungetch(), wgetch()
get (or push back) characters from curses terminal keyboard
Curses Function
SYNOPSIS DESCRIPTION Function Keys RETURN VALUES NOTES PORTABILITY AVAILABILITY SEE ALSO

--------------------------------------------------------------------------------

SYNOPSIS
#include <curses.h>

int getch(void);

int wgetch(WINDOW *win);

int mvgetch(int y, int x);

int mvwgetch(WINDOW *win, int y, int x);

int ungetch(int ch);

int has_key(int ch);


--------------------------------------------------------------------------------

DESCRIPTION
The
C++ Syntax (Toggle Plain Text) 
  1. getch(), wgetch(), mvgetch() and mvwgetch(),
routines read a character from the window. In no-delay mode, if no input is waiting, the value ERR is returned. In delay mode, the program waits until the system passes text through to the program. Depending on the setting of
C++ Syntax (Toggle Plain Text) 
  1. cbreak()
, this is after one character (cbreak mode), or after the first newline (nocbreak mode). In half-delay mode, the program waits until a character is typed or the specified timeout has been reached.

If
C++ Syntax (Toggle Plain Text) 
  1. noecho()
has been set, then the character will also be echoed into the designated window according to the following rules: If the character is the current erase character, left arrow, or backspace, the cursor is moved one space to the left and that screen position is erased as if
C++ Syntax (Toggle Plain Text) 
  1. delch()
had been called. If the character value is any other
C++ Syntax (Toggle Plain Text) 
  1. KEY_ define
, the user is alerted with a
C++ Syntax (Toggle Plain Text) 
  1. beep()
call. Otherwise the character is simply output to the screen.

If the window is not a pad, and it has been moved or modified since the last call to
C++ Syntax (Toggle Plain Text) 
  1. wrefresh(), wrefresh()
will be called before another character is read.

If keypad() is TRUE, and a function key is pressed, the token for that function key is returned instead of the raw characters. Possible function keys are defined in <curses.h> as macros with values outside the range of 8-bit characters whose names begin with KEY_. Thus, a variable intended to hold the return value of a function key must be of short size or larger.

When a character that could be the beginning of a function key is received (which, on modern terminals, means an escape character), curses sets a timer. If the remainder of the sequence does not come in within the designated time, the character is passed through; otherwise, the function key value is returned. For this reason, many terminals experience a delay between the time a user presses the escape key and the escape is returned to the program.

The ungetch() routine places ch back onto the input queue to be returned by the next call to wgetch(). Note that there is, in effect, just one input queue for all windows.

Function Keys
The following function keys, defined in <curses.h>, might be returned by getch() if keypad() has been enabled. Note that not all of these are necessarily supported on any particular terminal.
C++ Syntax (Toggle Plain Text) 
  1.        Name                    Key name
  2.        ------------------------------------------------------------------
  3.        KEY_BREAK            Break key
  4.        KEY_DOWN             The four arrow keys ...
  5.        KEY_UP
  6.        KEY_LEFT
  7.        KEY_RIGHT
  8.        KEY_HOME             Home key (upward+left arrow)
  9.        KEY_BACKSPACE        Backspace
  10.        KEY_F0               Function keys; space for 64 keys is reserved.
  11.        KEY_F(n)             For 0<n < 63
  12.        KEY_DL               Delete line
  13.        KEY_IL               Insert line
  14.        KEY_DC               Delete character
  15.        KEY_IC               Insert char or enter insert mode
  16.        KEY_EIC              Exit insert char mode
  17.        KEY_CLEAR            Clear screen
  18.        KEY_EOS              Clear to end of screen
  19.        KEY_EOL              Clear to end of line
  20.        KEY_SF               Scroll 1 line forward
  21.        KEY_SR               Scroll 1 line backward (reverse)
  22.        KEY_NPAGE            Next page
  23.        KEY_PPAGE            Previous page
  24.        KEY_STAB             Set tab
  25.        KEY_CTAB             Clear tab
  26.        KEY_CATAB            Clear all tabs
  27.        KEY_ENTER            Enter or send
  28.        KEY_SRESET           Soft (partial) reset
  29.        KEY_RESET            Reset or hard reset
  30.        KEY_PRINT            Print or copy
  31.        KEY_LL               Home down or bottom (lower left).  Keypad is
  32.                             arranged like this:
  33.                                  A1       up       A3
  34.                                  left     B2       right
  35.                                  C1       down     C3
  36.        KEY_A1               Upper left of keypad
  37.        KEY_A3               Upper right of keypad
  38.        KEY_B2               Center of keypad
  39.        KEY_C1               Lower left of keypad
  40.        KEY_C3               Lower right of keypad
  41.        KEY_BTAB             Back tab key
  42.        KEY_BEG              Beg(inning) key
  43.        KEY_CANCEL           Cancel key
  44.        KEY_CLOSE            Close key
  45.        KEY_COMMAND          Cmd (command) key
  46.        KEY_COPY             Copy key
  47.        KEY_CREATE           Create key
  48.        KEY_END              End key
  49.        KEY_EXIT             Exit key
  50.        KEY_FIND             Find key
  51.        KEY_HELP             Help key
  52.        KEY_MARK             Mark key
  53.        KEY_MESSAGE          Message key
  54.        KEY_MOVE             Move key
  55.        KEY_NEXT             Next object key
  56.        KEY_OPEN             Open key
  57.        KEY_OPTIONS          Options key
  58.        KEY_PREVIOUS         Previous object key
  59.        KEY_REDO             Redo key
  60.        KEY_REFERENCE        Ref(erence) key
  61.        KEY_REFRESH          Refresh key
  62.        KEY_REPLACE          Replace key
  63.        KEY_RESTART          Restart key
  64.        KEY_RESUME           Resume key
  65.        KEY_SAVE             Save key
  66.        KEY_SBEG             Shifted beginning key
  67.        KEY_SCANCEL          Shifted cancel key
  68.        KEY_SCOMMAND         Shifted command key
  69.        KEY_SCOPY            Shifted copy key
  70.        KEY_SCREATE          Shifted create key
  71.        KEY_SDC              Shifted delete char key
  72.        KEY_SDL              Shifted delete line key
  73.        KEY_SELECT           Select key
  74.        KEY_SEND             Shifted end key
  75.        KEY_SEOL             Shifted clear line key
  76.        KEY_SEXIT            Shifted exit key
  77.        KEY_SFIND            Shifted find key
  78.        KEY_SHELP            Shifted help key
  79.        KEY_SHOME            Shifted home key
  80.        KEY_SIC              Shifted input key
  81.        KEY_SLEFT            Shifted left arrow key
  82.        KEY_SMESSAGE         Shifted message key
  83.        KEY_SMOVE            Shifted move key
  84.        KEY_SNEXT            Shifted next key
  85.        KEY_SOPTIONS         Shifted options key
  86.        KEY_SPREVIOUS        Shifted prev key
  87.        KEY_SPRINT           Shifted print key
  88.        KEY_SREDO            Shifted redo key
  89.        KEY_SREPLACE         Shifted replace key
  90.        KEY_SRIGHT           Shifted right arrow
  91.        KEY_SRSUME           Shifted resume key
  92.        KEY_SSAVE            Shifted save key
  93.        KEY_SSUSPEND         Shifted suspend key
  94.        KEY_SUNDO            Shifted undo key
  95.        KEY_SUSPEND          Suspend key
  96.        KEY_UNDO             Undo key
The has_key() routine takes a key value from the above list, and returns TRUE or FALSE according as the current terminal type recognizes a key with that value.


--------------------------------------------------------------------------------

RETURN VALUES
All routines return the integer ERR upon failure and an integer value other than ERR (OK in the case of ungetch()) upon successful completion.


--------------------------------------------------------------------------

NOTES
Use of the escape key by a programmer for a single character function is discouraged, as it will cause a delay of up to one second while the keypad code looks for a following function-key sequence.

When using getch(), wgetch(), mvgetch(), or mvwgetch(), nocbreak mode (nocbreak()) and echo mode (echo()) should not be used at the same time. Depending on the state of the tty driver when each character is typed, the program may produce undesirable results.

Note that getch(), mvgetch(), and mvwgetch() may be macros.

Historically, the set of keypad macros was largely defined by the extremely function-key-rich keyboard of the AT&T 7300, aka 3B1, aka Safari 4. Modern personal computers usually have only a small subset of these. IBM PC-style consoles typically support little more than KEY_UP, KEY_DOWN, KEY_LEFT, KEY_RIGHT, KEY_HOME, KEY_END, KEY_NPAGE, KEY_PPAGE, and function keys 1 through 12. The Ins key is usually mapped to KEY_IC().


--------------------------------------------------------------------------------

PORTABILITY
The get* functions are described in the XSI Curses standard, Issue 4. They read single-byte characters only. The standard specifies that they return ERR on failure, but specifies no error conditions.

The echo behavior of these chars on input of KEY_ or backspace characters was not specified in the SVr4 documentation. This description is adopted from the XSI Curses standard.

The behavior of getch() and friends in the presence of handled signals is unspecified in the SVr4 and XSI Curses documentation. Under historical curses implementations, it varied depending on whether the operating system's implementation of handled signal receipt interrupts a read() call in progress or not, and also (in some implementations) depending on whether an input timeout or nonblocking mode hsd been set. Programmers concerned about portability should be prepared for either of two cases: (a) signal receipt does not interrupt getch(); (b) signal receipt interrupts getch() and causes it to return ERR with errno set to EINTR. Under the ncurses implementation, handled signals never interrupt getch().

The has_key() function is unique to ncurses. We recommend that any code using it be conditionalized on the NCURSES feature macro.


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Re: i want the user to enter an input without obligating him to press enter

 
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  #3
Jun 2nd, 2004
could you give us an example of code that when you press the up arrow it says up, then ends the line and the same for the other three arrows? i just want to see an example really... thanx
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Re: i want the user to enter an input without obligating him to press enter

 
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  #4
Jun 2nd, 2004
If you have conio.h...
C++ Syntax (Toggle Plain Text) 
  1. #include <stdio.h>
  2. #include <conio.h>
  3. #include <ctype.h>
  4.  
  5. #define ESC   27
  6. #define UP	72
  7. #define LEFT  75
  8. #define RIGHT 77
  9. #define DOWN  80
  10.  
  11. void foo(const char *prompt)
  12. {
  13.    puts(prompt);
  14.    for ( ;; )
  15.    {
  16. 	  int ch = getch();
  17. 	  switch(ch)
  18. 	  {
  19. 	  case EOF: 
  20. 	  case ESC:   return;
  21. 	  case UP:	puts("UP");	break;
  22. 	  case LEFT:  puts("LEFT");  break;
  23. 	  case RIGHT: puts("RIGHT"); break;
  24. 	  case DOWN:  puts("DOWN");  break;
  25. 	  default:	if(isprint(ch)) putchar(ch); break;
  26. 	  }
  27.    }
  28. }
  29.  
  30. int main(void)
  31. {
  32.    foo("press a key to test, <esc> to exit");
  33.    return 0;
  34. }
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Re: i want the user to enter an input without obligating him to press enter

 
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  #5
Jun 4th, 2004
is it possible you could paste the code for conio.h so i can make the header for it. im working with code warrior and it doesnt have it because it sucks... if you could, thanks...
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Re: i want the user to enter an input without obligating him to press enter

 
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  #6
Jun 4th, 2004
A header buys you nothing if you don't have the library it describes.
"One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand
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Re: i want the user to enter an input without obligating him to press enter

 
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  #7
Jun 5th, 2004
Here an example if u want to learn more tell me
C++ Syntax (Toggle Plain Text) 
  1.  
  2.    #include <ocurses.h>
  3.  
  4.    main()
  5.    {
  6.       int ch;
  7.  
  8.       initscr();
  9.       cbreak();
  10.           /* Explained later in the section "Input Options" */
  11.       addstr("Press any character:  ");
  12.       refresh();
  13.       ch = getch();
  14.       printw("\n\n\nThe character entered was a '%c'.\n", ch);
  15.       refresh();
  16.       endwin();
  17.    }
  18.  
  19. The output from this program follows. The first refresh sends the addstr character string from stdscr to the terminal: 
  20.  
  21.    Press any character:  []
  22.  
  23.  
  24.  
  25. Now assume that a w is typed at the keyboard. getch accepts the character and assigns it to ch. Finally, the second refresh is called and the screen appears as follows: 
  26.  
  27.    Press any character:  w
  28.  
  29.  
  30.    The character entered was a 'w'.
  31.  
  32.  
  33.    $[]
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Re: i want the user to enter an input without obligating him to press enter

 
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  #8
Jun 7th, 2004
Nevermind, I got it to work perfectly but thank you for the examples...
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