re-organized source, added Makefile, better Readme, added manpage

tossing.c

@@ -0,0 +1,124 @@
+/*
+ *    This file is part of dicepwgen
+ *
+ *    Copyright (C) 2015 T.v.Dein.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    You can contact me by mail: <tom AT vondein DOT org>.
+ */
+
+#include "tossing.h"
+
+unsigned char *toss(int count) {
+  /*
+    toss <count> dices. if the global humandice is enabled (option -t),
+    then ask the human to toss dices and enter the numbers interactively.
+    otherwise generate tosses from /dev/random.
+   */
+  
+  FILE *RAND;
+  int i;
+  int pos = 0;
+  uint8_t onedice;
+  unsigned char *tosses = NULL;
+  unsigned char *rand = NULL;
+  size_t len;
+  ssize_t linelen;
+ 
+  if(humantoss) {
+    char *line = NULL;
+    char digit[2];
+    digit[1] = '\0';
+   
+  RETRY:
+    fprintf(stderr, "enter 5 digits, each between 1-6\n");
+    linelen = getline(&line, &len, stdin);
+    tosses = malloc((size_t)count);
+    
+    if(linelen < 6) /* 5 digits max allowed */
+      goto RETRY;
+
+    for(i=0; i<count; i++) { /* only digits allowed */
+      if(isdigit(line[i]) == 0)
+	goto RETRY;
+
+      digit[0] = line[i];
+      onedice = atoi(digit);
+
+      if (onedice < 1 || onedice > 6) /* no dice digit */
+	goto RETRY;
+
+      tosses[i] = onedice;
+    }
+    free(line);
+  }
+  else {
+    rand = malloc(RLEN);
+ 
+    if((RAND = fopen("/dev/urandom", "rb")) == NULL)
+      perror("Could not open /dev/urandom");
+
+    if(fread(rand, RLEN, 1, RAND) != 1)
+      perror("Could not read from /dev/urandom");
+    
+    fclose(RAND);
+
+    tosses = malloc((size_t)count);
+    
+    for(i=0; i<RLEN; i++) {
+      onedice = rand[i];
+      onedice &= 7; /* only use the last 3 bits, 0-7 */
+      onedice %= 6; /* 6 is the max */
+      if(onedice >= 1 && onedice <= 6) {
+	tosses[pos] = onedice;
+	pos++;
+      }
+      if(pos == count)
+	break;
+    }
+    free(rand);
+  }
+ 
+  return tosses;
+}
+
+int rand_lim(int limit) {
+  /*
+    return a random number in the range [0..limit)
+   */
+
+    int divisor = RAND_MAX/limit;
+    int retval;
+
+    do { 
+        retval = rand() / divisor;
+    } while (retval == limit);
+
+    return retval;
+}
+
+
+
+int get_dicenum(int *digits) {
+  /*
+    get the actual number of an array of dice digits
+  */
+  int i = 0;
+  int pos = 0;
+  for(i=0; i<5; i++)
+    pos += digits[i];
+
+  return pos;
+}