First push

1 files changed, 801 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..30fe517
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,801 @@
+/* blabla */
+#include <stdio.h>
+#include <stdlib.h>
+#include "utils.h"
+#include "coordinates.h"
+#include "io.h"
+#include "moves.h"
+#include "solver.h"
+#include "string.h"
+
+char *commands[][10] = {
+  {"help", "[COMMAND]",
+   "Print this help, or a help page for COMMAND."},
+  {"save", "[MOVES|@ID|$ID]",
+   "Save or copy a scramble."},
+  {"change", "$ID1 [MOVES|$ID2|@ID2]",
+   "Change a memorized scramble."},
+  {"print", "[$ID|@ID]",
+   "Print memorized sequences."},
+  {"add", "[MOVES|$ID1|@ID1] $ID2",
+   "Add moves at the end of a memorized scramble."},
+  {"invert", "[MOVES|$ID|@ID]",
+   "Inverts the given sequence of moves."},
+  {"unniss", "[MOVES|$ID|@ID]}",
+   "Removes NISS: A (B) -> B\' A."},
+  {"pic",   "[MOVES|$ID|@ID]",
+   "Show a text description of the scrambled cube."},
+  {"solve", "[MOVES|$ID|@ID]",
+   "Solves a scramble."},
+  {"replace", "[MOVES|$ID|@ID]",
+   "Find non-optimal subsequences."},
+  {"eo", "[MOVES|$ID|@ID]",
+   "Solves EO."},
+  {"dr", "[MOVES|$ID|@ID]",
+   "Solves DR, either directly or from eo."},
+  {"htr", "[MOVES|$ID|@ID]",
+   "Solves HTR from DR."},
+  {"drfinish", "[MOVES|$ID|@ID]",
+   "Solves the cube after DR."},
+  {"htrfinish", "[MOVES|$ID|@ID]",
+   "Solves the cube using only half turns."},
+  {"drcorners", "[MOVES|$ID|@ID]",
+   "Solves corners after DR."},
+  {"exit", "",
+   "Exit nissy."},
+  {"quit", "",
+   "Exit nissy."},
+  {"", "", ""}
+};
+
+/* Saved sequences of moves */
+int scr_count=1, tmp_count=1, max_tmp=999;
+int scrambles[255][255], tmp[1000][255];
+
+int read_moves_from_variable(char *id, int *dst) {
+  char c = id[0];
+  if (c != '$' && c != '@')
+    return -1;
+  int n = atoi(id+1);
+  if (n <= 0 || n >= (c == '$' ? scr_count : tmp_count))
+    return -1;
+  copy_moves(c == '$' ? scrambles[n] : tmp[n], dst);
+  return n;
+}
+
+int read_moves_from_argument(int n, char tok[][100], int *dst) {
+  int r = read_moves_from_variable(tok[0], dst);
+  return  (r != -1) ? r : read_moves_from_tok(n, tok, dst);
+}
+
+void print_results(int n, int res[][21]) {
+  if (n == -1)
+    printf("Pre-conditions not satisfied (or other error).\n");
+
+  if (n == 0)
+    printf("No result found (try different bounds).\n");
+
+  if (n > 1)
+    printf("Found %d results.\n", n);
+  tmp_count = 1; /* Reset temporary count */
+  for (int i = 0; i < n; i++) {
+    if (i < max_tmp) {
+      copy_moves(res[i], tmp[tmp_count]);
+      printf("@%d:\t", tmp_count++);
+    } else {
+      printf("  \t");
+    }
+    print_moves(res[i]);
+    printf("(%d)\n", len(res[i]));
+  }
+}
+
+/* Removes extra white spaces from the input string */
+int parsecmd(char *cmd, char cmdtok[][100])  {
+  char *i = cmd, *j = cmd;
+  while (*j != '\n' && *j != EOF) {
+    *i = *j;
+    if (*i == ' ' || *i == '\t')
+      *i = ' ';
+    ++j;
+    if (*i == ' ' || *i == '\t')
+      while (*j == ' ' || *j == '\t')
+        ++j;
+    ++i;
+  }
+  if (*(i-1) == ' ')
+    *(i-1) = 0;
+  else
+    *i = 0;
+  
+  int n = 0;
+  char *s = strtok(cmd, " ");
+  while (s != NULL) {
+    strcpy(cmdtok[n++], s);
+    s = strtok(NULL, " ");
+  }
+  return n;
+}
+
+void help_cmd(int n, char cmdtok[][100]) {
+  if (n == 1) {
+    printf("\n");
+    for (int i = 0; commands[i][0][0]; i++)
+      printf("%-10s%-20s%s\n", commands[i][0], commands[i][1], commands[i][2]);
+    printf("\n");
+    printf("Type \'help\' followed by a command for a detailed help page.\n");
+    printf("Type \'help nissy\' for a general user guide.\n");
+  } else if (n == 2) {
+    char fname[255], line[255] = "";
+    FILE *file;
+    sprintf(fname, "docs/%s.txt", cmdtok[1]);
+    file = fopen(fname, "r");
+    if (file == NULL) {
+      printf("No help file for %s.\n", cmdtok[1]);
+      return;
+    }
+    while (fgets(line, 255, file) != NULL)
+      printf("%s", line);
+  } else {
+    printf("help: wrong syntax.\n");
+  }
+}
+
+void save_cmd(int n, char cmdtok[][100]) {
+  int scram[255];
+  if (n == 1) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("save: error reading moves. Not saved.\n");
+      return;
+    }
+  } else if (read_moves_from_argument(n-1, cmdtok+1, scram) == -1) {
+    printf("save: error reading moves or ID. Not saved.\n");
+    return;
+  }
+
+  copy_moves(scram, scrambles[scr_count]);
+
+  printf("$%d:\t", scr_count);
+  print_moves(scrambles[scr_count]);
+  printf("\n");
+  scr_count++;
+}
+
+void change_cmd(int n, char cmdtok[][100]) {
+  int id, scram[255];
+  if (n == 1) {
+    printf("change: you must specify an $ID.\n");
+    return;
+  } else if (cmdtok[1][0] != '$') {
+    printf("change: invalid $ID.\n");
+    return;
+  } else {
+    id = atoi(cmdtok[1]+1);
+    if (id <= 0 || id >= scr_count) {
+      printf("change: invalid $ID.\n");
+      return;
+    }
+    if (n == 2) {
+      if (read_moves_from_prompt(scram) == -1) {
+        printf("change: error reading moves.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-2, cmdtok+2, scram) == -1 ) {
+      printf("change: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  copy_moves(scram, scrambles[id]);
+
+  printf("$%d:\t", id);
+  print_moves(scrambles[id]);
+  printf("\n");
+}
+
+void print_cmd(int n, char cmdtok[][100]) {
+  if (n == 1) {
+    for (int i = 1; i < scr_count; i++) {
+      printf("$%d:\t", i);
+      print_moves(scrambles[i]);
+      printf("\n");
+    }
+  } else if (n == 2) {
+    int i = atoi(cmdtok[1]+1);
+    char sign = cmdtok[1][0];
+    if (sign != '$' && sign != '@') {
+      printf("print: invalid ID (must start with $ or @).\n");
+      return;
+    }
+    if (i > 0 && i < (sign == '$' ? scr_count : tmp_count)) {
+      printf("%c%d:\t", sign, i);
+      print_moves(sign == '$' ? scrambles[i] : tmp[i]);
+      printf("\n");
+    } else {
+      printf("print: invalid ID.\n");
+      return;
+    }
+  } else {
+    printf("print: wrong syntax.\n");
+  }
+}
+
+void add_cmd(int n, char cmdtok[][100]) {
+  int id, scram[255];
+  if (n == 1) {
+    printf("add: you must specify a destination $ID.\n");
+    return;
+  } else if (cmdtok[n-1][0] != '$') {
+    printf("add: invalid destination $ID.\n");
+    return;
+  } else {
+    id = atoi(cmdtok[n-1]+1);
+    if (id <= 0 || id >= scr_count) {
+      printf("add: invalid destination $ID.\n");
+      return;
+    }
+    if (n == 2) {
+      if (read_moves_from_prompt(scram) == -1) {
+        printf("add: error reading moves.\n");
+        return;
+      }
+    } else {
+      if (read_moves_from_argument(n-2, cmdtok+1, scram) == -1) {
+        printf("add: error reading moves or ID.\n");
+        return;
+      }
+    }
+  }
+
+  append_moves(scram, scrambles[id]);
+
+  printf("$%d:\t", id);
+  print_moves(scrambles[id]);
+  printf("\n");
+}
+
+void invert_cmd(int n, char cmdtok[][100]) {
+  int scram[255];
+  if (n == 1) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("invert: error reading moves.\n");
+      return;
+    }
+  } else if (read_moves_from_argument(n-1, cmdtok+1, scram) == -1) {
+    printf("invert: error reading moves or ID.\n");
+    return;
+  }
+
+  if (uses_niss(scram)) {
+    printf("invert: cannot invert NISS.\n");
+    return;
+  }
+
+  invert(scram, tmp[1]);
+  tmp_count = 2;
+
+  printf("@1:\t");
+  print_moves(tmp[1]);
+  printf("\n");
+}
+
+void unniss_cmd(int n, char cmdtok[][100]) {
+  int scram[255];
+  if (n == 1) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("unniss: error reading moves.\n");
+      return;
+    }
+  } else if (read_moves_from_argument(n-1, cmdtok+1, scram) == -1) {
+    printf("unniss: error reading moves or ID.\n");
+    return;
+  }
+  
+  unniss(scram, tmp[1]);
+  tmp_count = 2;
+
+  printf("@1:\t");
+  print_moves(tmp[1]);
+  printf("\n");
+}
+
+void pic_cmd(int n, char cmdtok[][100]) {
+  int scram[255];
+  if (n == 1) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("pic: error reading moves.\n");
+      return;
+    }
+  } else if (read_moves_from_argument(n-1, cmdtok+1, scram) == -1) {
+    printf("pic: error reading moves or ID.\n");
+    return;
+  }
+  print_cube_scram(scram);
+}
+
+void solve_cmd(int n, char cmdtok[][100]) {
+  int m = 1, b = 20, optimal = 0;
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("solve: bad option b.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+          printf("solve: bad option n.\n");
+        return;
+      }
+    } else if (!strcmp(cmdtok[i], "o")) {
+      optimal = 1;
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("solve: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("solve: error reading moves.\n");
+      return;
+    }
+  }
+
+  /* Call solver and print results */
+  unniss(scram, scram_unnissed);
+  int sol[m+2][21];
+  int s = solve_scram(scram_unnissed, sol, m, b, optimal);
+  print_results(s, sol);
+}
+
+void replace_cmd(int n, char cmdtok[][100]) {
+  int m = 10; /* max length */
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strncmp(cmdtok[i], "b=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+          printf("replace: bad option n.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("replace: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("replace: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+  int l = len(scram_unnissed);
+  int aux1[255], aux2[15][21], aux3[21];
+  for (int i = 0; i < l; i++) {
+    for (int j = 2; j <= m && i + j <= l; j++) {
+      copy_moves(scram_unnissed+i, aux1);
+      aux1[j] = 0;
+      int s = solve_scram(aux1, aux2, 10, j-1, 1);
+      for (int k = 0; k < s; k++) {
+        invert(aux2[k], aux3);
+        /* TODO: the following part should also chek for the case when
+         * the last moves are R L or similar. */
+        if (aux3[0] != aux1[0] && aux3[len(aux3)-1] != aux1[len(aux1)-1]) {
+          printf("Replace [ ");
+          print_moves(aux1);
+          printf("] (moves %d-%d) with: [ ", i+1, i+j);
+          print_moves(aux3);
+          printf("] (-%d+%d)\n", j, len(aux3));
+        }
+      }
+    }
+  }
+}     
+
+void eo_cmd(int n, char cmdtok[][100]) {
+  
+  /* Default values */
+  int m = 1, b = 20;
+  int niss = 0, hide = 1;
+  int fb = 1, rl = 1, ud = 1;
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+  
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strcmp(cmdtok[i], "h")) {
+      hide = 0;
+    } else if (!strcmp(cmdtok[i], "niss")) {
+      niss = 1;
+    } else if (!strncmp(cmdtok[i], "axis=", 5)) {
+      fb = rl = ud = 0;
+      if (strstr(cmdtok[i], "fb") != NULL)
+        fb = 1;
+      if (strstr(cmdtok[i], "rl") != NULL)
+        rl = 1;
+      if (strstr(cmdtok[i], "ud") != NULL)
+        ud = 1;
+      if (fb + rl + ud == 0) {
+        printf("eo: bad axis option.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+        printf("eo: bad option n.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("eo: bad option b.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("eo: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("eo: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+
+  /* Call solver and print results */
+  int eo_list[m+5][21];
+  int neo = eo_scram_spam(scram_unnissed, eo_list, fb, rl, ud, m, b, niss,
+                          hide);
+  print_results(neo, eo_list);
+}
+
+void dr_cmd(int n, char cmdtok[][100]) {
+  
+  /* Default values */
+  int m = 1, b = 20;
+  int niss = 0, hide = 1;
+  int from = 0; /* 0: direct dr; {1,2,3}: from {eofb,eorl,eoud} */
+  int fb = 1, rl = 1, ud = 1;
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+  
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strcmp(cmdtok[i], "h")) {
+      hide = 0;
+    } else if (!strcmp(cmdtok[i], "niss")) {
+      niss = 1;
+    } else if (!strncmp(cmdtok[i], "axis=", 5)) {
+      fb = rl = ud = 0;
+      if (strstr(cmdtok[i], "fb") != NULL)
+        fb = 1;
+      if (strstr(cmdtok[i], "rl") != NULL)
+        rl = 1;
+      if (strstr(cmdtok[i], "ud") != NULL)
+        ud = 1;
+      if (fb + rl + ud == 0) {
+        printf("dr: bad axis option.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+        printf("dr: bad option n.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("dr: bad option b.\n");
+        return;
+      }
+    } else if (!strcmp(cmdtok[i], "from")) {
+      i++;
+      char x[3][3] = {"fb", "rl", "ud"};
+      for (int j = 0; j < 3; j++)
+        if (!strcmp(cmdtok[i], x[j]))
+          from = j+1;
+      if (!from) {
+        printf("dr: bad from option.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("dr: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("dr: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+
+  /* Call solver */
+  int dr_list[m+5][21], ndr;
+  if (from) {
+    ndr = drfrom_scram_spam(scram_unnissed, dr_list, from, fb, rl, ud,
+                                m, b, niss, hide);
+    if (ndr == -1) {
+      printf("dr: from given, but EO not found (possibly other error).\n");
+      return;
+    }
+  } else {
+    if (niss)
+      printf("Warning: not using NISS for direct DR.\n");
+    ndr = dr_scram_spam(scram_unnissed, dr_list, fb, rl, ud, m, b, hide);
+  }
+  print_results(ndr, dr_list);
+}
+
+void htr_cmd(int n, char cmdtok[][100]) {
+
+  /* Default values */
+  int m = 1, b = 20;
+  int niss = 0, hide = 1;
+  int from = 0; /* 0: unspecified; {1,2,3}: from {ud,fb,rl} */
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strcmp(cmdtok[i], "h")) {
+      hide = 0;
+    } else if (!strcmp(cmdtok[i], "niss")) {
+      niss = 1;
+    } else if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+        printf("htr: bad option n.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("htr: bad option b.\n");
+        return;
+      }
+    } else if (!strcmp(cmdtok[i], "from")) {
+      i++;
+      char x[3][3] = {"ud", "fb", "rl"};
+      for (int j = 0; j < 3; j++)
+        if (!strcmp(cmdtok[i], x[j]))
+          from = j+1;
+      if (!from) {
+        printf("htr: bad from option.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("htr: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("htr: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+
+  /* Call solver */
+  int htr_list[m+5][21], nhtr;
+  nhtr = htr_scram_spam(scram_unnissed, htr_list, from, m, b, niss, hide);
+  print_results(nhtr, htr_list);
+}
+
+void drfinish_cmd(int n, char cmdtok[][100]) {
+  /* Default values */
+  int m = 1, b = 20;
+  int from = 0; /* 0: unspecified; {1,2,3}: from {ud,fb,rl} */
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+        printf("drfinish: bad option n.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("drfinish: bad option b.\n");
+        return;
+      }
+    } else if (!strcmp(cmdtok[i], "from")) {
+      i++;
+      char x[3][3] = {"ud", "fb", "rl"};
+      for (int j = 0; j < 3; j++)
+        if (!strcmp(cmdtok[i], x[j]))
+          from = j+1;
+      if (!from) {
+        printf("drfinish: bad from option.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("drfinish: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("drfinish: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+  
+  /* Call solver */
+  int c_list[m+5][21], nc;
+  nc = dr_finish_scram_spam(scram_unnissed, c_list, from, m, b);
+  print_results(nc, c_list);
+}
+
+void htrfinish_cmd(int n, char cmdtok[][100]) {
+  /* Default values */
+  int m = 1, b = 20;
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+        printf("htrfinish: bad option n.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("htrfinish: bad option b.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("htrfinish: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("htrfinish: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+  
+  /* Call solver */
+  int c_list[m+5][21], nc;
+  nc = htr_finish_scram_spam(scram_unnissed, c_list, m, b);
+  print_results(nc, c_list);
+}
+
+void drcorners_cmd(int n, char cmdtok[][100]) {
+  /* Default values */
+  int m = 1, b = 20, ignore=0;
+  int from = 0; /* 0: unspecified; {1,2,3}: from {ud,fb,rl} */
+  int scram[255] = {[0] = 0};
+  int scram_unnissed[255];
+
+  /* Parse options */
+  for (int i = 1; i < n && scram[0] == 0; i++) {
+    if (!strncmp(cmdtok[i], "n=", 2)) {
+      m = atoi(cmdtok[i]+2);
+      if (m <= 0) {
+        printf("drcorners: bad option n.\n");
+        return;
+      }
+    } else if (!strncmp(cmdtok[i], "b=", 2)) {
+      b = atoi(cmdtok[i]+2);
+      if (b <= 0) {
+        printf("drcorners: bad option b.\n");
+        return;
+      }
+    } else if (!strcmp(cmdtok[i], "i")) {
+      ignore = 1;
+    } else if (!strcmp(cmdtok[i], "from")) {
+      i++;
+      char x[3][3] = {"ud", "fb", "rl"};
+      for (int j = 0; j < 3; j++)
+        if (!strcmp(cmdtok[i], x[j]))
+          from = j+1;
+      if (!from) {
+        printf("drcorners: bad from option.\n");
+        return;
+      }
+    } else if (read_moves_from_argument(n-i, cmdtok+i, scram) == -1) {
+      printf("drcorners: error reading moves or ID.\n");
+      return;
+    }
+  }
+
+  if (scram[0] == 0) {
+    if (read_moves_from_prompt(scram) == -1) {
+      printf("drcorners: error reading moves.\n");
+      return;
+    }
+  }
+
+  unniss(scram, scram_unnissed);
+  
+  /* Call solver */
+  int c_list[m+5][21], nc;
+  nc = dr_corners_scram_spam(scram_unnissed, c_list, from, m, b, ignore);
+  print_results(nc, c_list);
+}
+
+
+void exit_quit_cmd(int n, char cmdtok[][100]) {
+  if (n == 1)
+    exit(0);
+  else
+    printf("%s: wrong synstax.\n", cmdtok[0]);
+}
+
+void (*cmd_list[])(int n, char cmdtok[][100]) = {
+  help_cmd, save_cmd, change_cmd, print_cmd,
+  add_cmd, invert_cmd, unniss_cmd, pic_cmd,
+  solve_cmd, replace_cmd,
+  eo_cmd, dr_cmd, htr_cmd,
+  drfinish_cmd, htrfinish_cmd, drcorners_cmd,
+  exit_quit_cmd, exit_quit_cmd, NULL
+};
+
+void execcmd(int n, char cmdtok[][100]) {
+  int i = 0;
+  while (strcmp(commands[i][0], cmdtok[0]) && strcmp(commands[i][0], ""))
+    i++;
+  if (strcmp(commands[i][0], ""))
+    (*cmd_list[i])(n, cmdtok);
+  else
+    printf("%s: not a command.\n", cmdtok[0]);
+}
+
+int main() {
+  init_transition_table();
+  init_possible_next();
+
+  printf("Type help for a list of commands.\n");
+
+  char cmd[1000] = "";
+  while (1) {
+    printf("nissy-# ");
+    if (fgets(cmd, 1000, stdin) == NULL)
+      break;
+    char cmdtok[100][100];
+    int n = parsecmd(cmd, cmdtok);
+    if (n == 0)
+      continue;
+    execcmd(n, cmdtok);
+  }
+
+  return 0;
+}