/*      maksub.c        */
#include <stdio.h>
#include "tools.h"
#include "ed.h"

char *
 maksub(sub, subsz)
char *sub;
int subsz;
{
  int size;
  char delim, *cp;

  size = 0;
  cp = sub;

  delim = *inptr++;
  for (size = 0; *inptr != delim && *inptr != NL && size < subsz; size++) {
        if (*inptr == '&') {
                *cp++ = DITTO;
                inptr++;
        } else if ((*cp++ = *inptr++) == ESCAPE) {
                if (size >= subsz) return(NULL);

                switch (toupper(*inptr)) {
                    case NL:    *cp++ = ESCAPE;         break;
                        break;
                    case 'S':
                        *cp++ = SP;
                        inptr++;
                        break;
                    case 'N':
                        *cp++ = NL;
                        inptr++;
                        break;
                    case 'T':
                        *cp++ = HT;
                        inptr++;
                        break;
                    case 'B':
                        *cp++ = BS;
                        inptr++;
                        break;
                    case 'R':
                        *cp++ = CR;
                        inptr++;
                        break;
                    case '0':{
                                int i = 3;
                                *cp = 0;
                                do {
                                        if (*++inptr < '0' || *inptr > '7')
                                                break;

                                        *cp = (*cp << 3) | (*inptr - '0');
                                } while (--i != 0);
                                cp++;
                        } break;
                    default:    *cp++ = *inptr++;       break;
                }
        }
  }
  if (size >= subsz) return(NULL);

  *cp = EOS;
  return(sub);
}