#include <search.h>
    #include <stdlib.h>
    #include <stdio.h>
    #include <errno.h>
    
    void *root=NULL;
    
    typedef struct
    {
      char symbol[8];
      char u;
      char e[3];
      char u13;
      char base[8];
      char plus;
      char displacement[8];
      char u31;
      char t;
      char p;
      char d[3];
      char u37;
      char source[4];
      char u42;
      char a;
      char r;
      char description[28];
      int reladdr;
      #define REL_MASK 0x0003ffff
      short nda;
      short resp_cnt;
      char reserved1[3];
      char status;
      #define ACTIVE 0x80
      #define COLLISION 0x08
      int reserved2;
    } DATAPOOL;

    int format=0;
    #define SAVE 1
    #define LOG  2
    char dp_file[128]="MAIN";
    FILE * dp_file_p;

    void *xmalloc(unsigned n)
    {
      void *p;
      p = malloc(n);
      if(p) return p;
      fprintf(stderr, "insufficient memory\n");
      exit(1);
      memset((char *) p, '\0',n);
    }
    
    int compare(const void *pa, const void *pb)
    {
      DATAPOOL *node1 = (DATAPOOL *) pa;
      DATAPOOL *node2 = (DATAPOOL *) pb;
//      fprintf(stderr, "compare: %8.8s|%8.8s\n",node1->symbol, node2->symbol);
      return (memcmp(node1->symbol, node2->symbol,sizeof(node1->symbol)));
    }
    
    void action(const void *nodep, const VISIT which, const int depth)
    {
      DATAPOOL *datap;
      void *val;
      int bytes_written;
    
      switch(which)
        {
        case preorder:
          break;
        case postorder:
          datap = *(DATAPOOL **)nodep;
          if (format==LOG)
            printf("         LOG     %72.72s              %6X %7d %2d\n",
                   (char *)&datap->symbol, datap->reladdr, datap->resp_cnt, 0);
          else if (format==SAVE) {
            if (96!= (bytes_written=fwrite((char *)datap, 1, 96, dp_file_p))) 
              perror("SAVE");
          }
          break;
        case endorder:
          datap = *(DATAPOOL **)nodep;
//          (void)tdelete(datap, &root, compare);
//          free(datap);
          break;
        case leaf:
          datap = *(DATAPOOL **)nodep;
          if (format==LOG)
            printf("         LOG     %72.72s              %6X %7d %2d\n",
                   (char *)&datap->symbol, datap->reladdr, datap->resp_cnt, 0);
          else if (format==SAVE) {
            if (96!= (bytes_written=fwrite((char *)datap, 1, 96, dp_file_p))) 
              perror("SAVE");
          }
//          val = tdelete(datap, &root, compare);
//          free(datap);
          break;
        }
      return;
    }
    
    int main()
    {
      int i;
      int bytes_read=0;
      int records_read=0;
      int rel_addr=-1;
      int disp=-1;
      int base_addr=-1;
      int dim=-1;
      void *val;
      DATAPOOL dp_record, *ptr;
      DATAPOOL base_record, *base_ptr;
      DATAPOOL old_record, *old_ptr, *del_ptr;
      char read_buffer[128];
    
      for (records_read=0;;records_read++)
        {
//          bytes_read=read(0, &read_buffer, 81);
//          if (0==bytes_read) break;
            if (NULL==fgets(read_buffer, 82, stdin)) break;
            bytes_read=strlen(read_buffer);
            for (i=bytes_read-1;i<81;i++) read_buffer[i]=' ';
            read_buffer[80]='\0';
//          if ((73 > bytes_read)||(81 < bytes_read)) {
//             perror("DPEDIT: read");
//             break;
//          }
          if (read_buffer[0]=='/') {
            //process DPEDIT directives
            if (0==strncmp(&read_buffer[1],"DPD",3)) {
              for (i=4;i<72 && read_buffer[i]==' ';i++);
              strncpy(dp_file, (char *)&read_buffer[i], 17);
              if (NULL==(dp_file_p=fopen(dp_file, "rb"))) {
                perror("DPD open failed");
                exit(1);
              } else {
                // read in existing datapool file
                do {
                  ptr = (DATAPOOL *)xmalloc(sizeof(dp_record));
                  bytes_read=fread(&read_buffer, 1, 96, dp_file_p);
                  memcpy((char *)ptr, &read_buffer, 96);
                  val = tsearch((void *)ptr, &root, compare);
                  if(val == NULL) {
                    fprintf(stderr, "DPEDIT: out of space to insert symbol %8.8s\n", read_buffer);
                    exit(1);
                  } 
                } while (96==bytes_read);
                fclose(dp_file_p);
              }
            } else if (0==strncmp(&read_buffer[1],"ENTER",5)) {
            }
            else if (0==strncmp(&read_buffer[1],"LOG",3)) {
              for (i=4;i<72 && read_buffer[i]==' ';i++) {
                if (0==strncmp(&read_buffer[i],"REL",3)) {
                } else if (0==strncmp(&read_buffer[i],"ALPHA",5)) {
                  printf("DPD: %s\n",dp_file);
printf(" ERROR   FUNCTION SYMBOL U E    BASE     DISP   TP D   SC  AR                   DESCRIPTION          RELATIVE    RESP CM\n");
printf(" CODE                          SYMBOL                                                                ADDRESS     CNT    \n");

                  
                  format=LOG;
                  twalk(root, action);
                } else {
                }
              }
            }
            else if (0==strncmp(&read_buffer[1],"REMAP",5)) {
              fprintf(stderr,"REMAP not implemented\n");
            }
            else if (0==strncmp(&read_buffer[1],"SAVE",4)) {
              if (NULL==(dp_file_p=fopen(dp_file, "wb"))) {
                perror("SAVE open failed");
                exit(1);
              } else {
                // write out internal tree to existing datapool file
                format=SAVE;
                twalk(root, action);
                fclose(dp_file_p);
              }
            }
            else if (0==strncmp(&read_buffer[1],"VERIFY",6)) {
              fprintf(stderr,"VERIFY not implemented\n");
            }
            else {
              fprintf(stderr,"Unknown DPEDIT directive %s16.16\n",read_buffer);
            }
          } else {
            //process DATAPOOL statements
            ptr = (DATAPOOL *)xmalloc(sizeof(dp_record));
            memcpy((char *)ptr, &read_buffer, 72);
            // If Change then merge fields as indicated
            if (ptr->u == '*') {
                memcpy(&old_record, (char*)ptr->base,8);
                old_ptr = *(DATAPOOL**) tfind((void *)&old_record, &root, compare);
                if(old_ptr == NULL) {
                  fprintf(stderr, "DPEDIT: old symbol not found");
                  exit(1);
                }
                // Update base field
                for (i=0;i<8;i++) {
                  if (ptr->base[i]==' ') ptr->base[i] = old_ptr->base[i];
                  else if (ptr->base[i]=='#') {
                    if (old_ptr->resp_cnt ) {
                      fprintf(stderr,"Can\'t change base\n");
                    }
                    else ptr->base[i] = ' ';
                  } else if (old_ptr->resp_cnt ) {
                      fprintf(stderr,"Can\'t change base\n");
                  }
                }
                // Update displacement field
                if (old_ptr->resp_cnt  && ptr->plus=='+') fprintf(stderr,"Can\'t change displacement\n");
                else {
                  for (i=0;i<8;i++) {
                    if (ptr->displacement[i]==' ') ptr->displacement[i] = old_ptr->displacement[i];
                    else if (ptr->displacement[i]=='#') ptr->displacement[i] = ' ';
                  }
                }
                // Update all other fields
                if (ptr->t==' ') ptr->t = old_ptr->t;
                else if (ptr->t=='#') ptr->t = ' ';
                if (ptr->p==' ') ptr->p = old_ptr->p;
                else if (ptr->p=='#') ptr->p = ' ';
                for (i=0;i<3;i++) {
                  if (ptr->d[i]==' ') ptr->d[i] = old_ptr->d[i];
                  else if (ptr->d[i]=='#') ptr->d[i] = ' ';
                }
                for (i=0;i<4;i++) {
                  if (ptr->source[i]==' ') ptr->source[i] = old_ptr->source[i];
                  else if (ptr->source[i]=='#') ptr->source[i] = ' ';
                }
                if (ptr->a==' ') ptr->a = old_ptr->a;
                else if (ptr->a=='#') ptr->a = ' ';
                if (ptr->r==' ') ptr->r = old_ptr->r;
                else if (ptr->r=='#') ptr->r = ' ';
                for (i=0;i<28;i++) {
                  if (ptr->description[i]==' ') ptr->description[i] = old_ptr->description[i];
                  else if (ptr->description[i]=='#') ptr->description[i] = ' ';
                }
            }
            // If Delete or Change then delete old record
            if ((ptr->u == '-') || (ptr->u == '*')) {
              memcpy(&base_record, (char*)ptr->base,8);
              base_ptr = *(DATAPOOL**) tfind((void *)&base_record, &root, compare);
              if(base_ptr != NULL) {
                fprintf(stderr, "DPEDIT: cannot delete base symbol");
                exit(1);
              } else {
                del_ptr = tdelete((void *)ptr, &root, compare);
                if(del_ptr == NULL) {
                  fprintf(stderr, "DPEDIT: symbol not found");
                  exit(1);
                }
              }
              if (ptr->u == '-') free(ptr);
            }
            // If Add or Change then insert new record
            if ((ptr->u == ' ') || (ptr->u == '*')) {
              if (ptr->base[0] == '$') {
                rel_addr=0;
              } else {
                memcpy(&base_record, (char*)ptr->base,8);
                base_ptr = *(DATAPOOL**) tfind((void *)&base_record, &root, compare);
                if(base_ptr == NULL) {
                  fprintf(stderr, "DPEDIT: base symbol not found");
                  exit(1);
                } else {
                  base_ptr->resp_cnt++;
                  base_addr = base_ptr->reladdr;
                  if ((ptr->plus==' ') && (ptr->displacement[0]==' ')) disp=0;
                  else if ((ptr->displacement[0] == 'X') && (ptr->displacement[1] == '\''))
                    sscanf(&(ptr->displacement[2]), "%x", &disp);
                  else {
                    sscanf(&(ptr->displacement[0]), "%d", &disp);
                    for (i=0;i<8 && isdigit(ptr->displacement[i]);i++);
                    if (i<8 && ptr->displacement[i]=='B') disp*=1;
                    else if (i<8 && ptr->displacement[i]=='H') disp*=2;
                    else if (i<8 && ptr->displacement[i]=='W') disp*=4;
                    else if (i<8 && ptr->displacement[i]=='D') disp*=8;
                  }
                rel_addr=base_addr+disp;
                }
              }
              ptr->reladdr= rel_addr;
              val = tsearch((void *)ptr, &root, compare);
              if(val == NULL) {
                fprintf(stderr, "DPEDIT: out of space to insert symbol %8.8s\n", ptr->symbol);
                exit(1);
              } 
            }
          }
        }
printf("         1         2         3         4         5         6         7         8         9         0         1         2\n");
printf("123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890\n");
printf("DPD: %s\n",dp_file);
printf(" ERROR   FUNCTION SYMBOL U E    BASE     DISP   TP D   SC  AR                   DESCRIPTION          RELATIVE    RESP CM\n");
printf(" CODE                          SYMBOL                                                                ADDRESS     CNT    \n");
      format=LOG;
      twalk(root, action);
      return 0;
    }