ncurses | gittup.org's ncurses

Missing the module.lds file in the latest kernel. Apply the following source code as a patch in the kernel and build the image.

Erlang does not compile into binary files, you still need the erlang runtime to be able to run the application, yet your final docker image is a fresh alpine install that doesn't have erlang installed

Rather than addch for that special case, you can insert a character using insch:

These routines insert the character ch before the character under the cursor. All characters to the right of the cursor are moved one space to the right, with the possibility of the rightmost character on the line being lost. The insertion operation does not change the cursor position.

For instance, you could decide to use that when the current cell contains something other than a blank. You can read that character using inch (similar spelling, different meaning):

These routines return the character, of type chtype, at the current position in the named window. If any attributes are set for that position, their values are OR'ed into the value returned. Constants defined in can be used with the & (logical AND) operator to extract the character or attributes alone.

(as noted in the manual page, AND the return value with A_CHARTEXT to get just the character).

Your programs have several bugs, I have fixed them. The most serious is that your code cannot be compiled in C++. If it's intended to build it under C++, you need to fix the compile errors at first.

1. newPiece = malloc(sizeof(struct snake));, need a convertion here: newPiece = (snake *)malloc(sizeof(struct snake));, generally it's not recomended to use malloc in c++, it's more naturally to use new

2. first = addNewPiece("#"); Pass string literal as char argument, need to pass a character here.

3. mvwprintw(win, y, x, t);, you have misunderstand the API, should be fixed as mvwprintw(win, y, x, "%c", t->piece);, you need to see the document before use a library API to see what types of arguments it expects

4. You forget to refresh the screen after printing the screen!

5. You haven't increment the index in for loop, it's an infinite loop.

Your code is somewhat c style, if you are trying to write with C++, it needs to be refactored, some suggestions:

• use std::vector to store the snake body, then we don't need to manage the memory by hand. And avoid the error-prone linked list processing. Then most part of your code can be simplified.
• Use a logging library and print logs to help to debug

The fixed code should work, I get a vertical snake on my console.

I replicated this error with the continuumio/miniconda2:4.5.11 Docker image:

Some of the allocation sizes are incorrect:

• frontier = malloc(sizeof(frontier) * MAXHEIGHT * MAXWIDTH); should be

An array containing the six characters \u4e09 is an array containing six characters, just as an array containing a backslash followed by an n is an array of two characters, not a newline. The compiler converts escape sequence in literals. Nothing (except what you yourself write) does anything to character arrays.

So your array wcsarr is not a single wide character. It's a (null-terminated) wide string using six wchar_t values to encode six ascii characters. setcchar requires that its second argument contain only one spacing character (possibly followed by several non-spacing combining characters), and your program does not conform to this specification.

You could do something like this:

Some history first.

Traditionally, the ESC key value has been used as the prefix for escape sequences, which denote special sequences of characters that can be interpreted as a non-graphic character (e.g., an arrow key, a function key, etc.)

Due to (n)curses focus on portability (and telecommunication), out of the box it supports this notion of escape sequences, and as such pressing the ESC key can have some side effects. Notably, when keypad is enabled, there is an inbuilt delay as the program waits to decide if the user simply pressed ESC or if it needs to wait for some more information to complete the escape sequence. This timing can be adjusted via the ESCDELAY environment variable, or the set_escdelay function.

All this is important as you work forward, as given its a game you may want to enable the functionality of the keypad eventually, which will create some extra steps when using the ESC key.

And because of all this, there is no ESC or KEY_ESC macro for for the escape key. Instead, its raw code is 27 (or the octal 033).

Your use of the halfdelay function seems perfectly fine to me, just know that the argument is in tenths of a second, so 5 is half a second. Tenths of a second may not achieve the desired effect in a game, so consider using the timeout function instead, which allows for higher precision.

A simple, working example:

You never update your x position inside the loop, so you repeatedly move to one before the right edge of your window.

Assuming you do not use maxX elsewhere, simply pre-decrement it within the loop.