BSD 4 release

[unix-history] / usr / src / cmd / compact / uncompact.c

/*
*  Uncompact adaptive Huffman code input to output
*
*  On - line algorithm
*
*  Input file does not contain decoding tree
*
*  Written by Colin L. Mc Master (UCB) February 14, 1979
*/

#include "compact.h"


main (argc, argv)
short argc;
char *argv [ ];
{
       register short i;
       register struct node *p;
       register short j;
       register int m;
       union cio c, d;
       char b;
       longint ic, n;
       char fname [LNAME], *cp;

       dir [513] . next = NULL;
       for (head = dir + (j = 513); j--; ) {
               dirp = head--;
               head -> next = dirp;
       }
       bottom = dirp -> pt = dict;
       dict [0] . top [0] = dict [0] . top [1] = dirp;
       dirq = dirp -> next;
       in [EF] . flags = FBIT | SEEN;

       for (i = 1; ; i++) {
               ic = oc = 0;
               (bottom -> top [1]) -> next = flist;
               bottom -> top [1] = dirp;
               flist = dirq;
               if (i >= argc) {
                       uncfp = stdout;
                       cfp = stdin;
               }
               else {
                       m = -1;
                       cp = fname;
                       for (j = 0; j < (LNAME - 3) && (*cp = argv [i][j]); j++)
                               if (*cp++ == '/') m = j;
                       if (cp [-1] == 'C' && cp [-2] == '.') cp [-2] = 0;
                       else {
                               fprintf (stderr, "%s: File name must end with \".C\"\n", argv [i]);
                               if (i == argc - 1) break;
                               continue;
                       }
                       if (j >= (LNAME - 3) || (j - m) > 15) {
                               fprintf (stderr, "File name too long -- %s\n", argv [i]);
                               if (i == argc - 1) break;
                               continue;
                       }
                       if ((cfp = fopen (argv [i], "r")) == NULL) {
                               perror (argv [i]);
                               if (i == argc - 1) break;
                               continue;
                       }
                       if ((uncfp = fopen (fname, "w")) == NULL) {
                               perror (fname);
                               fclose (cfp);
                               if (i == argc - 1) break;
                               continue;
                       }
                       fstat (fileno (cfp), &status);
                       chmod (fname, status.st_mode & 07777);
               }

               if ((c . integ = getc (cfp)) != EOF) {
                       if ((d . integ = getc (cfp)) != EOF) {
                               c . chars . hib = d . integ & 0377;
                               c . integ &= 0177777;
                               if (c . integ != COMPACTED) goto notcompact;
                               if ((c . integ = getc (cfp)) != EOF) {
                                       putc (c . chars . lob, uncfp);
                                       ic = 3;
               
                                       in [NC] . fp = in [EF] . fp = dict [0] . sp [0] . p = bottom = dict + 1;
                                       bottom -> count [0] = bottom -> count [1] = dict [0] . count [1] = 1;
                                       dirp -> next = dict [0] . top [1] = bottom -> top [0] = bottom -> top [1] = dirq = NEW;
                                       dirq -> next = NULL;
                                       dict [0] . fath . fp = NULL;
                                       dirq -> pt = bottom -> fath . fp = in [c . integ] . fp = dict;
                                       in [c . integ] . flags = (FBIT | SEEN);
                                       in [NC] . flags = SEEN;
                                       dict [0] . fath . flags = RLEAF;
                                       bottom -> fath . flags = (LLEAF | RLEAF);
                                       dict [0] . count [0] = 2;
               
                                       dict [0] . sp [1] . ch = c . integ;
                                       bottom -> sp [0] . ch = NC;
                                       bottom -> sp [1] . ch = EF;
               
                                       p = dict;
                                       while ((c . integ = getc (cfp)) != EOF) {
                                               ic++;
                                               for (m = 0200; m; ) {
                                                       b = (m & c . integ ? 1 : 0);
                                                       m >>= 1;
                                                       if (p -> fath . flags & (b ? RLEAF : LLEAF)) {
                                                               d . integ = p -> sp [b] . ch;
                                                               if (d . integ == EF) break;
                                                               if (d . integ == NC) {
                                                                       uptree (NC);
                                                                       d . integ = 0;
                                                                       for (j = 8; j--; m >>= 1) {
                                                                               if (m == 0) {
                                                                                       c . integ = getc (cfp);
                                                                                       ic++;
                                                                                       m = 0200;
                                                                               }
                                                                               d . integ <<= 1;
                                                                               if (m & c . integ) d . integ++;
                                                                       }
                                                                       insert (d . integ);
                                                               }
                                                               uptree (d . integ);
                                                               putc (d . chars . lob, uncfp);
                                                               oc++;
                                                               p = dict;
                                                       }
                                                       else p = p -> sp [b] . p;
                                               }
                                       }
                               }
                       }
                       else goto notcompact;
               }
               else {
                       notcompact : if (i < argc) {
                                            fprintf (stderr, "%s: ", argv [i]);
                                            unlink (fname);
                                    }
                                    if (c . integ == PACKED) fprintf (stderr, "File is packed. Use unpack.\n");
                                    else fprintf (stderr, "Not a compacted file.\n");
                                    if (i >= argc) break;
                                    goto closeboth;
               }

               if (ferror (uncfp) || ferror (cfp))
                       if (i < argc) {
                               if (ferror (uncfp))
                                       perror (fname);
                               else
                                       perror (argv [i]);
                               fprintf (stderr, "Unable to uncompact %s\n", argv [i]);
                               unlink (fname);
                               goto closeboth;
                       }
                           if (i >= argc) break;
                           fprintf (stderr, "%s uncompacted to %s\n", argv [i], fname);
                           unlink (argv [i]);
               closeboth : fclose (cfp);
               closein   : fclose (uncfp);
                           if (i == argc - 1) break;
                           for (j = 256; j--; ) in [j] . flags = 0;
                           continue;
               fail      : fprintf (stderr, "Unsuccessful uncompact of standard input to standard output.\n");
                           break;
       }
}