I have a Probclem with functions keys in curses.h.
I have this littel programm seen on different websites/tutorials
#include <ncurses.h>
int main()
{ int ch;
initscr(); /* Start curses mode */
raw(); /* Line buffering disabled */
keypad(stdscr, TRUE); /* We get F1, F2 etc.. */
noecho(); /* Don't echo() while we do getch */
printw("Type any character to see it in bold\n");
ch = getch();
while (ch != KEY_F(1))
{
if(ch == KEY_F(1))
printw("F1 Key pressed: Ending program.\n");
else
{ printw("The pressed key is ");
attron(A_BOLD);
printw("%c\n", ch);
attroff(A_BOLD);
}
refresh();
ch = getch();
}
printw("end\n");
endwin(); /* End curses mode */
return 0;
}
The keys F6-F12 works fine and the code which is returned is also fine (for example: 270 if F6 ist pressed). But if I press F5 not 269 is returned, like it would be supposed to be, instead the following is happening (only by pressing F5 once):
Type any character to see it in bold
The pressed key is ^[
27
The pressed key is [
91
The pressed key is 1
49
The pressed key is 5
53
The pressed key is ~
126
So I think the whole Escape Sequence ist returned. I read on the internet about this problem and two times there was a hint which describes to change the TERM variable to xterm or vt100. So I tried to change TERM to vt 220 and also xterm, but nothing change. When i changed it to vt100 also F6-F12 didn't work.
Can anybody help me how I can recognize if the user presses F1-F5? Keys like enter, Backspace, up, down, etc. are recognized fine.
best regards
Sounds like a disagreement between what terminfo says your terminal sends and what it actually does. May be the result of an incorrect terminfo file on the target machine, or the wrong $TERM setting, or any number of things.
I'd start by comparing what
$ infocmp -L
says on the target machine, as compared what the terminal actually sends when running, say, cat.
If you are running xterm, maybe you have a ~/.Xresources file translating your function keys. VMS users often would remap F1 - F5 keys that way. Also many terminal emulators (like Putty) have options to remap these keys.
Related
I derived my own control from CEdit and it behaves as I intend:
#define IsSHIFTpressed() ( (GetKeyState(VK_SHIFT) & (1 << (sizeof(SHORT)*8-1))) != 0 )
void CEditEx::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)
{
if (IsCTRLpressed() && nChar == 2)
{
// Do something
return;
}
if (IsCTRLpressed() && nChar == 9)
{
// Do something
return;
}
CEdit::OnChar(nChar, nRepCnt, nFlags);
}
However, I have two questions about how I am detecting the key press:
Is it possible to detect CTRL being pressed from inside OnChar without the need to use GetKeyState?
Are there any constants for comparing against "b" (2) and "i" (9)? I only knew I needed to use those numeric values from when I debugged into the handler.
As you have noted, the value of the nChar argument to OnChar for keyboard entries of Ctrl + "a letter" (independent of the case) will be the ASCII "control-key" values, 1 (for "a") thru 26 (for "z").
To answer your second point: a search through the <WinUser.h> header file shows no VK_xxx tokens for these; however, be aware that some of these control codes are used (by convention) for other actions: Ctrl+M (decimal 13) is equivalent to Return or Enter, and the header has #define VK_RETURN 0x0D; further, for one of your specific cases, Ctrl+I (9) is the ASCII TAB character, and the header, accordingly, has the #define VK_TAB 0x09 definition.
Although the Ctrl+B ASCII code (0x02) is much less used these days (STX, or "Start of Text"), that value is used by Windows for the right mouse button (#define VK_RBUTTON 0x02).
So, to answer your first point: Yes, you will need to make the GetKeyState(VK_CONTROL) check! Without that, a right-click will likely give you a false Ctrl+B and the Tab key will give a false Ctrl+I.
Furthermore, though I have no 'hard evidence' other than your own investigations, I think that a right-click while the Control key is down will generate a different value for nChar (i.e. not 2), and Ctrl+Tab will generate an nChar different from that for Tab alone.
What is the proper way of catching a control+key in ncurses?
current im doing it defining control like this:
#define ctl(x) ((x) & 0x1f)
it works ok, but the problem is that i cannot catch C-j and ENTER at the same time, and this is because:
j = 106 = 1101010
0x1f = 31 = 0011111
1101010 & 0011111 = 0001010 = 10 = ENTER key..
So.. how shall I catch it?
Thanks!
--
Edit:
If i try the code below,
I am not able to catch the enter key correctly, not even in the numeric keyboard. Enter gets catched as ctrl-j.
#include <stdio.h>
#include <ncurses.h>
#define ctrl(x) ((x) & 0x1f)
int main(void) {
initscr();
int c = getch();
nonl();
switch (c) {
case KEY_ENTER:
printw("key: %c", c);
break;
case ctrl('j'):
printw("key: ctrl j");
break;
}
getch();
endwin();
return;
}
New code:
#include <stdio.h>
#include <ncurses.h>
#define ctrl(x) ((x) & 0x1f)
int main(void) {
initscr();
int l = -1;
int c = getch();
cbreak();
noecho();
nonl();
keypad(stdscr, TRUE);
switch (c) {
case KEY_ENTER:
printw("key: %c", c);
break;
case ctrl('j'):
printw("key: ctrl j");
break;
}
printw("\nnow press a key to end");
getch();
endwin();
return;
}
Try nonl:
The nl and nonl routines control whether the underlying display device
translates the return key into newline on input, and whether it translates newline into return and line-feed on output (in either case, the
call addch('\n') does the equivalent of return and line feed on the
virtual screen). Initially, these translations do occur. If you disable them using nonl, curses will be able to make better use of the
line-feed capability, resulting in faster cursor motion. Also, curses
will then be able to detect the return key.
Further reading: the Notes section of the getch manual page:
Generally, KEY_ENTER denotes the character(s) sent by the Enter key on
the numeric keypad:
the terminal description lists the most useful keys,
the Enter key on the regular keyboard is already handled by the
standard ASCII characters for carriage-return and line-feed,
depending on whether nl or nonl was called, pressing "Enter" on the
regular keyboard may return either a carriage-return or line-feed,
and finally
"Enter or send" is the standard description for this key.
That addresses the question about newline/carriage-return translation. A followup comment is a reminder to point out that the manual page gives basic advice in the Initialization section:
To get character-at-a-time input without echoing (most interactive,
screen oriented programs want this), the following sequence should be
used:
initscr(); cbreak(); noecho();
and that OP's sample program did not use cbreak (or raw). The manual page for cbreak says
Normally, the tty driver buffers typed characters until a newline or
carriage return is typed. The cbreak routine disables line buffering
and erase/kill character-processing (interrupt and flow control characters are unaffected), making characters typed by the user immediately
available to the program. The nocbreak routine returns the terminal to
normal (cooked) mode.
Initially the terminal may or may not be in cbreak mode, as the mode is
inherited; therefore, a program should call cbreak or nocbreak explicitly. Most interactive programs using curses set the cbreak mode.
Note that cbreak overrides raw. (See curs_getch(3x) for a discussion
of how these routines interact with echo and noecho.)
Also, in curs_getch you may read
If keypad is TRUE, and a function key is pressed, the token for that
function key is returned instead of the raw characters:
The predefined function keys are listed in <curses.h> as macros
with values outside the range of 8-bit characters. Their names begin with KEY_.
That is, curses will only return KEY_ENTER if the program calls keypad:
keypad(stdscr, TRUE);
For the sake of discussion, here is an example fixing some of the problems with your sample program as of May 17:
#include <stdio.h>
#include <ncurses.h>
#define ctrl(x) ((x) & 0x1f)
int
main(void)
{
int c;
initscr();
keypad(stdscr, TRUE);
cbreak();
noecho();
nonl();
c = getch();
switch (c) {
case KEY_ENTER:
printw("\nkey_enter: %d", c);
break;
case ctrl('j'):
printw("\nkey: ctrl j");
break;
default:
printw("\nkeyname: %d = %s\n", c, keyname(c));
break;
}
printw("\nnow press a key to end");
getch();
endwin();
return 0;
}
That is, you have to call keypad before getch, and the value returned for KEY_ENTER is not a character (it cannot be printed with %c).
Running on the Linux console with the usual terminal description, you will see only carriage return for the numeric keypad Enter, because that description does not use application mode. Linux console does support application mode, and a corresponding description could be written. As a quick check (there are differences...) you could set TERM=vt100 to see the KEY_ENTER.
I wrote a program that i used ncurses library, i used, keys menu windows and other its facilities.
I run my program without any error.
After quit program, i can't see any input data (certainly same you run passwd command and wanna input new password), for example if you run ls, i can see output of ls(list of current dir) , but i can't see ls word.
How i solve this problem?
piece of my code:
WINDOW *menu_win,*qmenu_win,*amenu_win,*smenu_win;
char *query;
char *fields;
WriteFile *writePtr = new WriteFile();
ReadFile *readPtr = new ReadFile();
int highlight = 1;
int choice = 0;
int c;
initscr();
clear();
noecho();
cbreak(); /* Line buffering disabled. pass on everything */
startx = (80 - WIDTH) / 2;
starty = (24 - HEIGHT) / 2;
menu_win = newwin(HEIGHT, WIDTH, starty, startx);
keypad(menu_win, TRUE);
mvprintw(0, 0, "Use arrow keys to go up and down, Press enter to select a choice");
refresh();
print_menu(menu_win, highlight);
while (true)
Make sure your program calls endwin() before exiting. Otherwise, the state of the terminal may not be restored.
When this happens, type reset at your prompt.
Also be aware that problems may be due to your terminal program itself. If it does not properly emulate the terminal it claims to emulate, you will run into problems.
Or it could be a bug with your program: maybe you need to replace noecho with echo?
I am using a custom keymap using langmap option in vimrc.
I am trying to use snipmate but I am running into trouble. When I type a word and hit tab it allows me to edit the parameter. The problem is that the first character is the remapped one, while I want it to be the actual key.
For instance, I'll type this:
for
and hit tab to expand the snippet:
for (i = 0; i < COUNT; ++i)
The i is highlighted which means I can edit it. I type "aaa":
for (baa = 0; i < COUNT; ++i)
It comes out baa even though I typed aaa. This is because I remapped a and b.
How can I fix this?
Here is my keymapping:
set langmap=nj,N},ek,E{,il,IL,{^,}$,lb,LB,uw,UW,ye,YE,jg,JG,\\;z,f\\.,F\\,,zu,ZU,.?,\\,/,/v,? V,ta,TA,si,SI,ro,RO,ac,AC,wr,WR,xx,XX,dd,DD,bs,BS,gf,GF,pt,PT,kn,KN,cy,CY,vp,VP,o\\;
It won't make much sense to others, and I haven't finalized how I want it to look.
From your :set langmap I understand that you mapped a to c so, by typing aaa, did you expect to obtain ccc?
From what I understand (:help langmap), your custom substitutions are not available in INSERT mode for actually inserting stuff and I don't see a mention of the SELECT mode you are in when overwriting SnipMate's placeholders.
If I do this
:set langmap+=ac,bs
and I type aaa in SELECT mode, I obtain caa.
That's because langmap applies to the first a (:help Select-mode) and, therefore inserts c. But, after this first character I am in INSERT mode for all subsequent characters. Since langmap doesn't apply in INSERT mode, aa is inserted as is.
What is not clear to me is why you obtain baa instead of caa. Your langmap seems to be pretty clear about your intention: you want a to insert c and b to insert s. Typing a shouldn't insert b.
I smell a risk of mistyping in your .vimrc. Try this: reset your set langmap and start adding your mappings one by one.
May I ask you what is the purpose of such a massive remapping?
C program which outputs mappings similar behavior to langmap but not for select:
/* input:
lhs rhs optional-descripton
lhs rhs ...
*/
#include <stdlib.h>
#include <stdio.h>
int main() {
FILE *fi = fopen("in.txt", "r");
FILE *fo = fopen("out.txt", "w");
char lc[8], rc[8];
while (fscanf(fi, "\n%s %s", lc, rc) != EOF) {
fprintf(fo, "nnoremap %s %s\n", lc, rc);
fprintf(fo, "xnoremap %s %s\n", lc, rc);
fprintf(fo, "onoremap %s %s\n", lc, rc);
while (fgetc(fi) != '\n');
}
fclose(fo);
fclose(fi);
}
It doesn't work identically to langmap and so it might break other bindings.
This has now been fixed in vim 7.4.1150. See
https://github.com/vim/vim/issues/572
for details.
I have a problem here and need your help. I've been trying to capture keyboard strokes using cvWaitKey() function.
cvWaitKey(10) should return the keyboard stroke pressed every 10ms.
But in my case, I'm getting every 18 seconds, all the keys that I've pressed during this period of 18 seconds, at once.
And the window that should normally close when I press 'esc' (see the code) is still open.
In console I get this:
VIDIOC_QUERYMENU:Invalid argument
VIDIOC_QUERYMENU:Invalid argument
VIDIOC_QUERYMENU:Invalid argument
-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-11536870939-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-111536870939-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1
With:
1536870939 corresponds to when I pressed 'esc'
-1 correspond to when no key was pressed
Thanks for help.
#include "opencv/cv.h"
#include "opencv/highgui.h"
#include "iostream"
using namespace std;
int main()
{
IplImage *src=cvCreateImage(cvSize(640,480), 8, 3);
CvCapture* capture =cvCaptureFromCAM(CV_CAP_ANY);
int key;
while(1){
src = cvRetrieveFrame( capture );
cvNamedWindow( "out", CV_WINDOW_AUTOSIZE );
cvShowImage( "out", src );
key = cvWaitKey(10);
cout<<key;
if( key == 1536870939 ) break; //if 'esc' is pressed (in ubuntu 10.04)
cvGrabFrame( capture );
}
cvDestroyAllWindows();
cvReleaseCapture( &capture );
return 0;
}
I'm using: Opencv 2.2.0 , ubuntu 10.04 LTS , CodeBlocks 8.02
try using a 0xff mask to return 27 on an ESC key press:
if( (cvWaitKey(10)&0xff) == 27 ) break;
Alternatively, you can cast to a character:
if( (char)cvWaitKey(10) == 27 ) break;
The cause of the problem is the way cout works: it buffers characters and only sends them to the console if you send a newline character or if you explicitly ask it to do so. (Third case: the buffer gets full... but that's what you have to wait 18 seconds for.)
So put either cout << '\n'; or cout.flush(); after your current cout statement.
(By the way: VIDIOC_QUERYMENU:Invalid argument is from the v4l (webcam) driver... and I have no idea where 1536870939 comes from, ESC should be 27 :))