Texplode KotH controller

Question

I am creating a KotH (King of the Hill) challenge for Programming Puzzles and Code Golf. Other site users will write programs that play Texplode (a version of this game on a square grid). The program works, but I don't think it's anywhere near perfect; I don't often publish C programs so I rarely get any critique on them.

Here is the code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
bool move(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize], int playernum, int movepos);
bool hascounters(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize], int playernum);
void writegrid(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize], int playernum, FILE *file);
bool readinput(FILE *file, int *movepos);
void printoutput(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize]);
int main(int argc, char *argv[]) {
 if (argc < 3) {
 printf("Texplode, by wizzwizz4.\n");
 printf("Based on Hexplode.\n");
 printf("The first argument is the board size.\n");
 printf("The second argument is the number of players.\n");
 printf("The 2n+1th argument is the nth player's input file.\n");
 printf("The 2n+2th argument is the nth player's output file.\n");
 printf("Human-readable ANSI art will be printed to STDOUT.\n");
 return 0;
 }
 int boardsize = atoi(argv[1]);
 int playercount = atoi(argv[2]);
 if (argc < (2 * playercount + 3)) {
 printf("You promised more players than you gave me.\n");
 }
 FILE *playerinv[playercount];
 FILE *playeroutv[playercount];
 for (int i = 0; i < playercount; i++) {
 playerinv[i] = fopen(argv[2 * i + 3], "r");
 playeroutv[i] = fopen(argv[2 * i + 4], "w");
 }
 int board[boardsize * boardsize];
 memset(board, 0, sizeof(board));
 int boardown[boardsize * boardsize];
 bool stillplaying[playercount];
 memset(stillplaying, true, sizeof(stillplaying));
 bool playoverride = true;
 int numplaying = playercount;
 while (1) {
 if (numplaying <= 1) {
 break;
 }
 for (int i = 0; i < playercount; i++) {
 if (stillplaying[i] || playoverride) {
 writegrid(boardsize, board, boardown, i, playeroutv[i]);
 int movepos = 0;
 if (!readinput(playerinv[i], &movepos)) {
 printf("Error! :-S\n");
 }
 move(boardsize, board, boardown, i, movepos);
 numplaying = 0;
 for (int j = 0; j < playercount; j++) {
 if (hascounters(boardsize, board, boardown, j)) {
 numplaying += 1;
 stillplaying[j] = true;
 } else {
 stillplaying[j] = false;
 }
 }
 }
 printoutput(boardsize, board, boardown);
 }
 playoverride = false;
 }
 printf("Game over.\n");
}
bool move(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize], int playernum, int movepos) {
 if (movepos >= boardsize * boardsize) {
 return false;
 }
 if (board[movepos] == 0) {
 board[movepos] = 1;
 boardown[movepos] = playernum;
 return true;
 }
 if (boardown[movepos] == playernum) {
 board[movepos] += 1;
 /* Cascade */
 bool notdone = true;
 while (notdone) {
 notdone = false;
 for (int i = 0; i < boardsize * boardsize; i++) {
 int neighbourcount = 4;
 unsigned int neighbours = 0xf;
 if (i / boardsize == 0) {
 neighbourcount -= 1;
 neighbours &= ~0x1;
 }
 if (i / boardsize == boardsize - 1) {
 neighbourcount -= 1;
 neighbours &= ~0x2;
 }
 if (i % boardsize == 0) {
 neighbourcount -= 1;
 neighbours &= ~0x4;
 }
 if (i % boardsize == boardsize - 1) {
 neighbourcount -= 1;
 neighbours &= ~0x8;
 }
 if (board[i] >= neighbourcount) {
 notdone = true;
 board[i] -= neighbourcount;
 boardown[i] = playernum;
 if (neighbours & 0x1) {
 board[i - boardsize] += 1;
 boardown[i - boardsize] = playernum;
 }
 if (neighbours & 0x2) {
 board[i + boardsize] += 1;
 boardown[i + boardsize] = playernum;
 }
 if (neighbours & 0x4) {
 board[i - 1] += 1;
 boardown[i - 1] = playernum;
 }
 if (neighbours & 0x8) {
 board[i + 1] += 1;
 boardown[i + 1] = playernum;
 }
 }
 }
 }
 return true;
 }
 return false;
}
bool hascounters(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize], int playernum) {
 for (int i = 0; i < boardsize * boardsize; i++) {
 if (board[i] && boardown[i] == playernum) {
 return true;
 }
 }
 return false;
}
void writegrid(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize], int playernum, FILE *file) {
 for (int i = 0; i < boardsize * boardsize; i++) {
 if (board[i] == 0) {
 putc('0', file);
 continue;
 }
 if (boardown[i] == playernum) {
 putc('3' + board[i], file);
 } else {
 putc('0' + board[i], file);
 }
 }
 putc(';', file);
 fflush(file);
}
bool readinput(FILE *file, int *movepos) {
 return (fscanf(file, "%d;", movepos) == 1); /* 1 "%d", one match. */
}
void printoutput(int boardsize, int board[boardsize * boardsize], int boardown[boardsize * boardsize]) {
 printf("\x1B[1;1H");
 for (int x = 0, i = 0; x < boardsize; x += 1) {
 for (; i < (x + 1) * boardsize; i++) {
 if (board[i]) {
 printf("\x1B[%dm%d", boardown[i] + 30, board[i]);
 } else {
 printf("\x1B[m ");
 }
 }
 printf("\n");
 }
}

I also have a basic UI program that I used for testing on Windows, where I don't have the luxury of using /dev/ttyn files. I know that this is not well-written, but I am providing it so that people have a way to test any changes that they make.

#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <string.h>
char * getline(void);
int main(int argc, char* argv[]) {
 /* "\\.\pipe\" pipename */
 HANDLE pipein = CreateNamedPipe(
 argv[1],
 PIPE_ACCESS_INBOUND,
 PIPE_TYPE_BYTE,
 PIPE_UNLIMITED_INSTANCES,
 0, /* Out buffer */
 256, /* In buffer */
 0, /* Default wait timeout */
 NULL
 );
 HANDLE pipeout = CreateNamedPipe(
 argv[2],
 PIPE_ACCESS_OUTBOUND,
 PIPE_TYPE_BYTE,
 PIPE_UNLIMITED_INSTANCES,
 256, /* Out buffer */
 0, /* In buffer */
 0, /* Default wait timeout */
 NULL
 );
 while (1) {
 if (_kbhit()) { /* Keyboard hit */
 char* input = getline();
 WriteFile(
 pipeout,
 input,
 strlen(input),
 NULL,
 NULL
 );
 free(input);
 }
 DWORD availbytes = 0;
 PeekNamedPipe(
 pipein,
 NULL,
 0,
 NULL,
 &availbytes,
 NULL
 );
 if (availbytes) {
 char byte;
 ReadFile(
 pipein,
 &byte,
 1,
 NULL,
 NULL
 );
 printf("%c", byte);
 }
 }
}
/* https://stackoverflow.com/a/314422/5223757 */
char * getline(void) {
 char * line = malloc(100), * linep = line;
 size_t lenmax = 100, len = lenmax;
 int c;
 if(line == NULL)
 return NULL;
 for(;;) {
 c = fgetc(stdin);
 if(c == EOF)
 break;
 if(--len == 0) {
 len = lenmax;
 char * linen = realloc(linep, lenmax *= 2);
 if(linen == NULL) {
 free(linep);
 return NULL;
 }
 line = linen + (line - linep);
 linep = linen;
 }
 if((*line++ = c) == '\n')
 break;
 }
 *line = '0円';
 return linep;
}

• mbomb007: You shouldn't assume that people here know what KotH stands for.