/* compress - Reduce file size using Modified Lempel-Ziv encoding */ /* * compress.c - File compression ala IEEE Computer, June 1984. * * Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas) * Jim McKie (decvax!mcvax!jim) * Steve Davies (decvax!vax135!petsd!peora!srd) * Ken Turkowski (decvax!decwrl!turtlevax!ken) * James A. Woods (decvax!ihnp4!ames!jaw) * Joe Orost (decvax!vax135!petsd!joe) * * Richard Todd Port to MINIX * Andy Tanenbaum Cleanup * * * Algorithm from "A Technique for High Performance Data Compression", * Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19. * * Usage: compress [-dfvc] [-b bits] [file ...] * Inputs: * -d: If given, decompression is done instead. * * -c: Write output on stdout. * * -b: Parameter limits the max number of bits/code. * * -f: Forces output file to be generated, even if one already * exists, and even if no space is saved by compressing. * If -f is not used, the user will be prompted if stdin is * a tty, otherwise, the output file will not be overwritten. * * -v: Write compression statistics * * file ...: Files to be compressed. If none specified, stdin * is used. * Outputs: * file.Z: Compressed form of file with same mode, owner, and utimes * or stdout (if stdin used as input) * * Assumptions: * When filenames are given, replaces with the compressed version * (.Z suffix) only if the file decreases in size. * Algorithm: * Modified Lempel-Ziv method (LZW). Basically finds common * substrings and replaces them with a variable size code. This is * deterministic, and can be done on the fly. Thus, the decompression * procedure needs no input table, but tracks the way the table was built. */ #define AZTEC86 1 #define min(a,b) ((a>b) ? b : a) /* * Set USERMEM to the maximum amount of physical user memory available * in bytes. USERMEM is used to determine the maximum BITS that can be used * for compression. * * SACREDMEM is the amount of physical memory saved for others; compress * will hog the rest. */ #ifndef SACREDMEM #define SACREDMEM 0 #endif #ifndef USERMEM # define USERMEM 450000 /* default user memory */ #endif #define REGISTER register #define DOTZ ".Z" #include #include /* The default for Minix is -b13, but we can do -b16 if the machine can. */ #define DEFAULTBITS 13 #if INT_MAX == 32767 # define BITS 13 #else # define BITS 16 #endif #ifdef USERMEM # if USERMEM >= (433484+SACREDMEM) # define PBITS 16 # else # if USERMEM >= (229600+SACREDMEM) # define PBITS 15 # else # if USERMEM >= (127536+SACREDMEM) # define PBITS 14 # else # if USERMEM >= (73464+SACREDMEM) # define PBITS 13 # else # define PBITS 12 # endif # endif # endif # endif # undef USERMEM #endif /* USERMEM */ #ifdef PBITS /* Preferred BITS for this memory size */ # ifndef BITS # define BITS PBITS # endif #endif /* PBITS */ #if BITS == 16 # define HSIZE 69001 /* 95% occupancy */ #endif #if BITS == 15 # define HSIZE 35023 /* 94% occupancy */ #endif #if BITS == 14 # define HSIZE 18013 /* 91% occupancy */ #endif #if BITS == 13 # define HSIZE 9001 /* 91% occupancy */ #endif #if BITS <= 12 # define HSIZE 5003 /* 80% occupancy */ #endif /* * a code_int must be able to hold 2**BITS values of type int, and also -1 */ #if BITS > 15 typedef long int code_int; #else typedef int code_int; #endif #ifdef SIGNED_COMPARE_SLOW typedef unsigned long int count_int; typedef unsigned short int count_short; #else typedef long int count_int; #endif #ifdef NO_UCHAR typedef char char_type; #else typedef unsigned char char_type; #endif /* UCHAR */ char_type magic_header[] = "\037\235"; /* 1F 9D */ /* Defines for third byte of header */ #define BIT_MASK 0x1f #define BLOCK_MASK 0x80 /* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is a fourth header byte (for expansion). */ #define INIT_BITS 9 /* initial number of bits/code */ #include #include #include #include #include #include #include #include #include #include #define ARGVAL() (*++(*argv) || (--argc && *++argv)) int n_bits; /* number of bits/code */ int maxbits = DEFAULTBITS; /* user settable max # bits/code */ code_int maxcode; /* maximum code, given n_bits */ code_int maxmaxcode = 1 << BITS; /* should NEVER generate this code */ #ifdef COMPATIBLE /* But wrong! */ # define MAXCODE(n_bits) (1 << (n_bits) - 1) #else # define MAXCODE(n_bits) ((1 << (n_bits)) - 1) #endif /* COMPATIBLE */ #ifndef AZTEC86 count_int htab [HSIZE]; unsigned short codetab [HSIZE]; #else count_int *htab; unsigned short *codetab; # define HTABSIZE ((size_t)(HSIZE*sizeof(count_int))) # define CODETABSIZE ((size_t)(HSIZE*sizeof(unsigned short))) #define htabof(i) htab[i] #define codetabof(i) codetab[i] #endif /* XENIX_16 */ code_int hsize = HSIZE; /* for dynamic table sizing */ count_int fsize; /* * To save much memory, we overlay the table used by compress() with those * used by decompress(). The tab_prefix table is the same size and type * as the codetab. The tab_suffix table needs 2**BITS characters. We * get this from the beginning of htab. The output stack uses the rest * of htab, and contains characters. There is plenty of room for any * possible stack (stack used to be 8000 characters). */ #define tab_prefixof(i) codetabof(i) #ifdef XENIX_16 # define tab_suffixof(i) ((char_type *)htab[(i)>>15])[(i) & 0x7fff] # define de_stack ((char_type *)(htab2)) #else /* Normal machine */ # define tab_suffixof(i) ((char_type *)(htab))[i] # define de_stack ((char_type *)&tab_suffixof(1< debug * -V => print Version; debug verbose * -d => do_decomp * -v => unquiet * -f => force overwrite of output file * -n => no header: useful to uncompress old files * -b maxbits => maxbits. If -b is specified, then maxbits MUST be * given also. * -c => cat all output to stdout * -C => generate output compatible with compress 2.0. * if a string is left, must be an input filename. */ for (argc--, argv++; argc > 0; argc--, argv++) { if (**argv == '-') { /* A flag argument */ while (*++(*argv)) { /* Process all flags in this arg */ switch (**argv) { #ifdef DEBUG case 'D': debug = 1; break; case 'V': verbose = 1; version(); break; #else case 'V': version(); break; #endif /* DEBUG */ case 'v': quiet = 0; break; case 'd': do_decomp = 1; break; case 'f': case 'F': overwrite = 1; force = 1; break; case 'n': nomagic = 1; break; case 'C': block_compress = 0; break; case 'b': if (!ARGVAL()) { fprintf(stderr, "Missing maxbits\n"); Usage(); exit(1); } maxbits = atoi(*argv); goto nextarg; case 'c': zcat_flg = 1; break; case 'q': quiet = 1; break; default: fprintf(stderr, "Unknown flag: '%c'; ", **argv); Usage(); exit(1); } } } else { /* Input file name */ *fileptr++ = *argv; /* Build input file list */ *fileptr = NULL; /* process nextarg; */ } nextarg: continue; } if(maxbits < INIT_BITS) maxbits = INIT_BITS; if (maxbits > BITS) maxbits = BITS; maxmaxcode = 1 << maxbits; if (*filelist != NULL) { for (fileptr = filelist; *fileptr; fileptr++) { exit_stat = 0; if (do_decomp != 0) { /* DECOMPRESSION */ /* Check for .Z suffix */ #ifndef PCDOS if (strcmp(*fileptr + strlen(*fileptr) - 2, DOTZ) != 0) #else if (strcmp(*fileptr + strlen(*fileptr) - 1, DOTZ) != 0) #endif { /* No .Z: tack one on */ strcpy(tempname, *fileptr); #ifndef PCDOS strcat(tempname, DOTZ); #else /* either tack one on or replace last character */ { char *dot; if (NULL == (dot = strchr(tempname,'.'))) { strcat(tempname,".Z"); } else /* if there is a dot then either tack a z on or replace last character */ { if (strlen(dot) < 4) strcat(tempname,DOTZ); else dot[3] = 'Z'; } } #endif *fileptr = tempname; } /* Open input file */ if ((freopen(*fileptr, "r", stdin)) == NULL) { perror(*fileptr); continue; } /* Check the magic number */ if (nomagic == 0) { unsigned magic1, magic2; if (((magic1 = getc(stdin)) != (magic_header[0] & 0xFF)) || ((magic2 = getc(stdin)) != (magic_header[1] & 0xFF))) { fprintf(stderr, "%s: not in compressed format %x %x\n", *fileptr,magic1,magic2); continue; } maxbits = getc(stdin); /* set -b from file */ block_compress = maxbits & BLOCK_MASK; maxbits &= BIT_MASK; maxmaxcode = 1 << maxbits; if(maxbits > BITS) { fprintf(stderr, "%s: compressed with %d bits, can only handle %d bits\n", *fileptr, maxbits, BITS); continue; } } /* Generate output filename */ strcpy(ofname, *fileptr); #ifndef PCDOS ofname[strlen(*fileptr) - 2] = '\0'; /* Strip off .Z */ #else /* kludge to handle various common three character extension */ { char *dot; char fixup = '\0'; /* first off, map name to upper case */ for (dot = ofname; *dot; dot++) *dot = toupper(*dot); if (NULL == (dot = strchr(ofname,'.'))) { fprintf(stderr,"Bad filename %s\n",ofname); exit(1); } if (strlen(dot) == 4) /* we got three letter extensions */ { if (strcmp(dot,".EXZ") == 0) fixup = 'E'; else if (strcmp(dot,".COZ") == 0) fixup = 'M'; else if (strcmp(dot,".BAZ") == 0) fixup = 'S'; else if (strcmp(dot,".OBZ") == 0) fixup = 'J'; else if (strcmp(dot,".SYZ") == 0) fixup = 'S'; else if (strcmp(dot,".DOZ") == 0) fixup = 'C'; } /* replace the Z */ ofname[strlen(*fileptr) - 1] = fixup; } #endif } else { /* COMPRESSION */ if (strcmp(*fileptr + strlen(*fileptr) - 2, DOTZ) == 0) { fprintf(stderr, "%s: already has .Z suffix -- no change\n", *fileptr); continue; } /* Open input file */ if ((freopen(*fileptr, "r", stdin)) == NULL) { perror(*fileptr); continue; } (void)stat( *fileptr, &statbuf ); fsize = (long) statbuf.st_size; /* * tune hash table size for small files -- ad hoc, * but the sizes match earlier #defines, which * serve as upper bounds on the number of output codes. */ hsize = HSIZE; /*lint -e506 -e712 */ if ( fsize < (1 << 12) ) hsize = min ( 5003, HSIZE ); else if ( fsize < (1 << 13) ) hsize = min ( 9001, HSIZE ); else if ( fsize < (1 << 14) ) hsize = min ( 18013, HSIZE ); else if ( fsize < (1 << 15) ) hsize = min ( 35023, HSIZE ); else if ( fsize < 47000 ) hsize = min ( 50021, HSIZE ); /*lint +e506 +e712 */ /* Generate output filename */ strcpy(ofname, *fileptr); #ifndef BSD4_2 /* Short filenames */ if ((cp=strrchr(ofname,'/')) != NULL) cp++; else cp = ofname; if (strlen(cp) >= _DIRENT_NAME_LEN-3) { fprintf(stderr,"%s: filename too long to tack on .Z\n",cp); continue; } #ifdef PCDOS else { /* either tack one on or replace last character */ char *dot; if (NULL == (dot = strchr(cp,'.'))) { strcat(cp,".Z"); } else /* if there is a dot then either tack a z on or replace last character */ { if (strlen(dot) < 4) strcat(cp,DOTZ); else dot[3] = 'Z'; } } #endif #endif /* BSD4_2 Long filenames allowed */ #ifndef PCDOS /* PCDOS takes care of this above */ strcat(ofname, DOTZ); #endif } /* Check for overwrite of existing file */ if (overwrite == 0 && zcat_flg == 0) { if (stat(ofname, &statbuf) == 0) { char response[2]; int fd; response[0] = 'n'; fprintf(stderr, "%s already exists;", ofname); if (foreground()) { fd = open("/dev/tty", O_RDONLY); fprintf(stderr, " do you wish to overwrite %s (y or n)? ", ofname); fflush(stderr); (void)read(fd, response, 2); while (response[1] != '\n') { if (read(fd, response+1, 1) < 0) { /* Ack! */ perror("stderr"); break; } } close(fd); } if (response[0] != 'y') { fprintf(stderr, "\tnot overwritten\n"); continue; } } } if(zcat_flg == 0) { /* Open output file */ if (freopen(ofname, "w", stdout) == NULL) { perror(ofname); continue; } if(!quiet) fprintf(stderr, "%s: ", *fileptr); } /* Actually do the compression/decompression */ if (do_decomp == 0) compress(); #ifndef DEBUG else decompress(); #else else if (debug == 0) decompress(); else printcodes(); if (verbose) dump_tab(); #endif /* DEBUG */ if(zcat_flg == 0) { copystat(*fileptr, ofname); /* Copy stats */ if((exit_stat == 1) || (!quiet)) putc('\n', stderr); } } } else { /* Standard input */ if (do_decomp == 0) { compress(); #ifdef DEBUG if(verbose) dump_tab(); #endif /* DEBUG */ if(!quiet) putc('\n', stderr); } else { /* Check the magic number */ if (nomagic == 0) { if ((getc(stdin)!=(magic_header[0] & 0xFF)) || (getc(stdin)!=(magic_header[1] & 0xFF))) { fprintf(stderr, "stdin: not in compressed format\n"); exit(1); } maxbits = getc(stdin); /* set -b from file */ block_compress = maxbits & BLOCK_MASK; maxbits &= BIT_MASK; maxmaxcode = 1 << maxbits; fsize = 100000; /* assume stdin large for USERMEM */ if(maxbits > BITS) { fprintf(stderr, "stdin: compressed with %d bits, can only handle %d bits\n", maxbits, BITS); exit(1); } } #ifndef DEBUG decompress(); #else if (debug == 0) decompress(); else printcodes(); if (verbose) dump_tab(); #endif /* DEBUG */ } } return(exit_stat); } static int offset; long int in_count = 1; /* length of input */ long int bytes_out; /* length of compressed output */ long int out_count = 0; /* # of codes output (for debugging) */ /* * compress stdin to stdout * * Algorithm: use open addressing double hashing (no chaining) on the * prefix code / next character combination. We do a variant of Knuth's * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime * secondary probe. Here, the modular division first probe is gives way * to a faster exclusive-or manipulation. Also do block compression with * an adaptive reset, whereby the code table is cleared when the compression * ratio decreases, but after the table fills. The variable-length output * codes are re-sized at this point, and a special CLEAR code is generated * for the decompressor. Late addition: construct the table according to * file size for noticeable speed improvement on small files. Please direct * questions about this implementation to ames!jaw. */ void compress() { REGISTER long fcode; REGISTER code_int i = 0; REGISTER int c; REGISTER code_int ent; #ifdef XENIX_16 REGISTER code_int disp; #else /* Normal machine */ REGISTER int disp; #endif REGISTER code_int hsize_reg; REGISTER int hshift; #ifndef COMPATIBLE if (nomagic == 0) { putc(magic_header[0],stdout); putc(magic_header[1],stdout); putc((char)(maxbits | block_compress),stdout); if(ferror(stdout)) writeerr(); } #endif /* COMPATIBLE */ offset = 0; bytes_out = 3; /* includes 3-byte header mojo */ out_count = 0; clear_flg = 0; ratio = 0; in_count = 1; checkpoint = CHECK_GAP; maxcode = MAXCODE(n_bits = INIT_BITS); free_ent = ((block_compress) ? FIRST : 256 ); ent = getc(stdin); hshift = 0; for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L ) hshift++; hshift = 8 - hshift; /* set hash code range bound */ hsize_reg = hsize; cl_hash( (count_int) hsize_reg); /* clear hash table */ #ifdef SIGNED_COMPARE_SLOW while ( (c = getc(stdin)) != (unsigned) EOF ) #else while ( (c = getc(stdin)) != EOF ) #endif { in_count++; fcode = (long) (((long) c << maxbits) + ent); i = ((c << hshift) ^ ent); /* xor hashing */ if ( htabof (i) == fcode ) { ent = codetabof (i); continue; } else if ( (long)htabof (i) < 0 ) /* empty slot */ goto nomatch; disp = hsize_reg - i; /* secondary hash (after G. Knott) */ if ( i == 0 ) disp = 1; probe: if ( (i -= disp) < 0 ) i += hsize_reg; if ( htabof (i) == fcode ) { ent = codetabof (i); continue; } if ( (long)htabof (i) > 0 ) goto probe; nomatch: output ( (code_int) ent ); out_count++; ent = c; #ifdef SIGNED_COMPARE_SLOW if ( (unsigned) free_ent < (unsigned) maxmaxcode) #else if ( free_ent < maxmaxcode ) #endif { codetabof (i) = free_ent++; /* code -> hashtable */ htabof (i) = fcode; } else if ( (count_int)in_count >= checkpoint && block_compress ) cl_block (); } /* * Put out the final code. */ output( (code_int)ent ); out_count++; output( (code_int)-1 ); /* * Print out stats on stderr */ if(zcat_flg == 0 && !quiet) { #ifdef DEBUG fprintf( stderr, "%ld chars in, %ld codes (%ld bytes) out, compression factor: ", in_count, out_count, bytes_out ); prratio( stderr, in_count, bytes_out ); fprintf( stderr, "\n"); fprintf( stderr, "\tCompression as in compact: " ); prratio( stderr, in_count-bytes_out, in_count ); fprintf( stderr, "\n"); fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n", free_ent - 1, n_bits ); #else /* !DEBUG */ fprintf( stderr, "Compression: " ); prratio( stderr, in_count-bytes_out, in_count ); #endif /* DEBUG */ } if(bytes_out > in_count) /* exit(2) if no savings */ exit_stat = 2; return; } /***************************************************************** * TAG( output ) * * Output the given code. * Inputs: * code: A n_bits-bit integer. If == -1, then EOF. This assumes * that n_bits =< (long)wordsize - 1. * Outputs: * Outputs code to the file. * Assumptions: * Chars are 8 bits long. * Algorithm: * Maintain a BITS character long buffer (so that 8 codes will * fit in it exactly). Use the VAX insv instruction to insert each * code in turn. When the buffer fills up empty it and start over. */ static char buf[BITS]; #ifndef vax char_type lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00}; char_type rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff}; #endif /* vax */ void output( code ) code_int code; { #ifdef DEBUG static int col = 0; #endif /* DEBUG */ /* * On the VAX, it is important to have the REGISTER declarations * in exactly the order given, or the asm will break. */ REGISTER int r_off = offset, bits= n_bits; REGISTER char * bp = buf; #ifndef BREAKHIGHC #ifdef METAWARE int temp; #endif #endif #ifdef DEBUG if ( verbose ) fprintf( stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' ); #endif /* DEBUG */ if ( code >= 0 ) { #ifdef vax /* VAX DEPENDENT!! Implementation on other machines is below. * * Translation: Insert BITS bits from the argument starting at * offset bits from the beginning of buf. */ 0; /* Work around for pcc -O bug with asm and if stmt */ asm( "insv 4(ap),r11,r10,(r9)" ); #else /* not a vax */ /* * byte/bit numbering on the VAX is simulated by the following code */ /* * Get to the first byte. */ bp += (r_off >> 3); r_off &= 7; /* * Since code is always >= 8 bits, only need to mask the first * hunk on the left. */ #ifndef BREAKHIGHC #ifdef METAWARE *bp &= rmask[r_off]; temp = (code << r_off) & lmask[r_off]; *bp |= temp; #else *bp = (*bp & rmask[r_off]) | ((code << r_off) & lmask[r_off]); #endif #else *bp = (*bp & rmask[r_off]) | ((code << r_off) & lmask[r_off]); #endif bp++; bits -= (8 - r_off); code >>= (8 - r_off); /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */ if ( bits >= 8 ) { *bp++ = code; code >>= 8; bits -= 8; } /* Last bits. */ if(bits) *bp = code; #endif /* vax */ offset += n_bits; if ( offset == (n_bits << 3) ) { bp = buf; bits = n_bits; bytes_out += bits; do putc(*bp++,stdout); while(--bits); offset = 0; } /* * If the next entry is going to be too big for the code size, * then increase it, if possible. */ if ( free_ent > maxcode || (clear_flg > 0)) { /* * Write the whole buffer, because the input side won't * discover the size increase until after it has read it. */ if ( offset > 0 ) { if( fwrite( buf, (size_t)1, (size_t)n_bits, stdout ) != n_bits) writeerr(); bytes_out += n_bits; } offset = 0; if ( clear_flg ) { maxcode = MAXCODE (n_bits = INIT_BITS); clear_flg = 0; } else { n_bits++; if ( n_bits == maxbits ) maxcode = maxmaxcode; else maxcode = MAXCODE(n_bits); } #ifdef DEBUG if ( debug ) { fprintf( stderr, "\nChange to %d bits\n", n_bits ); col = 0; } #endif /* DEBUG */ } } else { /* * At EOF, write the rest of the buffer. */ if ( offset > 0 ) fwrite( buf, (size_t)1, (size_t)(offset + 7) / 8, stdout ); bytes_out += (offset + 7) / 8; offset = 0; fflush( stdout ); #ifdef DEBUG if ( verbose ) fprintf( stderr, "\n" ); #endif /* DEBUG */ if( ferror( stdout ) ) writeerr(); } } /* * Decompress stdin to stdout. This routine adapts to the codes in the * file building the "string" table on-the-fly; requiring no table to * be stored in the compressed file. The tables used herein are shared * with those of the compress() routine. See the definitions above. */ void decompress() { REGISTER char_type *stackp; REGISTER int finchar; REGISTER code_int code, oldcode, incode; /* * As above, initialize the first 256 entries in the table. */ maxcode = MAXCODE(n_bits = INIT_BITS); for ( code = 255; code >= 0; code-- ) { tab_prefixof(code) = 0; tab_suffixof(code) = (char_type)code; } free_ent = ((block_compress) ? FIRST : 256 ); finchar = oldcode = getcode(); if(oldcode == -1) /* EOF already? */ return; /* Get out of here */ putc( (char)finchar,stdout ); /* first code must be 8 bits = char */ if(ferror(stdout)) /* Crash if can't write */ writeerr(); stackp = de_stack; while ( (code = getcode()) > -1 ) { if ( (code == CLEAR) && block_compress ) { for ( code = 255; code >= 0; code-- ) tab_prefixof(code) = 0; clear_flg = 1; free_ent = FIRST - 1; if ( (code = getcode ()) == -1 ) /* O, untimely death! */ break; } incode = code; /* * Special case for KwKwK string. */ if ( code >= free_ent ) { *stackp++ = finchar; code = oldcode; } /* * Generate output characters in reverse order */ #ifdef SIGNED_COMPARE_SLOW while ( ((unsigned long)code) >= ((unsigned long)256) ) { #else while ( code >= 256 ) { #endif *stackp++ = tab_suffixof(code); code = tab_prefixof(code); } *stackp++ = finchar = tab_suffixof(code); /* * And put them out in forward order */ do putc ( *--stackp ,stdout); while ( stackp > de_stack ); /* * Generate the new entry. */ if ( (code=free_ent) < maxmaxcode ) { tab_prefixof(code) = (unsigned short)oldcode; tab_suffixof(code) = finchar; free_ent = code+1; } /* * Remember previous code. */ oldcode = incode; } fflush( stdout ); if(ferror(stdout)) writeerr(); } /***************************************************************** * TAG( getcode ) * * Read one code from the standard input. If EOF, return -1. * Inputs: * stdin * Outputs: * code or -1 is returned. */ code_int getcode() { /* * On the VAX, it is important to have the REGISTER declarations * in exactly the order given, or the asm will break. */ REGISTER code_int code; static int offset = 0, size = 0; static char_type buf[BITS]; REGISTER int r_off, bits; REGISTER char_type *bp = buf; if ( clear_flg > 0 || offset >= size || free_ent > maxcode ) { /* * If the next entry will be too big for the current code * size, then we must increase the size. This implies reading * a new buffer full, too. */ if ( free_ent > maxcode ) { n_bits++; if ( n_bits == maxbits ) maxcode = maxmaxcode; /* won't get any bigger now */ else maxcode = MAXCODE(n_bits); } if ( clear_flg > 0) { maxcode = MAXCODE (n_bits = INIT_BITS); clear_flg = 0; } size = fread( buf, (size_t)1, (size_t)n_bits, stdin ); if ( size <= 0 ) return -1; /* end of file */ offset = 0; /* Round size down to integral number of codes */ size = (size << 3) - (n_bits - 1); } r_off = offset; bits = n_bits; #ifdef vax asm( "extzv r10,r9,(r8),r11" ); #else /* not a vax */ /* * Get to the first byte. */ bp += (r_off >> 3); r_off &= 7; /* Get first part (low order bits) */ #ifdef NO_UCHAR code = ((*bp++ >> r_off) & rmask[8 - r_off]) & 0xff; #else code = (*bp++ >> r_off); #endif /* NO_UCHAR */ bits -= (8 - r_off); r_off = 8 - r_off; /* now, offset into code word */ /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */ if ( bits >= 8 ) { #ifdef NO_UCHAR code |= (*bp++ & 0xff) << r_off; #else code |= *bp++ << r_off; #endif /* NO_UCHAR */ r_off += 8; bits -= 8; } /* high order bits. */ code |= (*bp & rmask[bits]) << r_off; #endif /* vax */ offset += n_bits; return code; } #ifndef AZTEC86 char * strrchr(s, c) /* For those who don't have it in libc.a */ REGISTER char *s, c; { char *p; for (p = NULL; *s; s++) if (*s == c) p = s; return(p); } #endif #ifndef METAWARE #ifdef DEBUG printcodes() { /* * Just print out codes from input file. For debugging. */ code_int code; int col = 0, bits; bits = n_bits = INIT_BITS; maxcode = MAXCODE(n_bits); free_ent = ((block_compress) ? FIRST : 256 ); while ( ( code = getcode() ) >= 0 ) { if ( (code == CLEAR) && block_compress ) { free_ent = FIRST - 1; clear_flg = 1; } else if ( free_ent < maxmaxcode ) free_ent++; if ( bits != n_bits ) { fprintf(stderr, "\nChange to %d bits\n", n_bits ); bits = n_bits; col = 0; } fprintf(stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' ); } putc( '\n', stderr ); exit( 0 ); } #ifdef DEBUG2 code_int sorttab[1<= 0) { sorttab[codetabof(i)] = i; } } first = block_compress ? FIRST : 256; for(i = first; i < free_ent; i++) { fprintf(stderr, "%5d: \"", i); stack[--stack_top] = '\n'; stack[--stack_top] = '"'; /* " */ stack_top = in_stack((int)(htabof(sorttab[i])>>maxbits)&0xff, stack_top); for(ent=htabof(sorttab[i]) & ((1< 256; ent=htabof(sorttab[ent]) & ((1<> maxbits), stack_top); } stack_top = in_stack(ent, stack_top); fwrite( &stack[stack_top], (size_t)1, (size_t)(STACK_SIZE-stack_top), stderr); stack_top = STACK_SIZE; } } else if(!debug) { /* decompressing */ for ( i = 0; i < free_ent; i++ ) { ent = i; c = tab_suffixof(ent); if ( isascii(c) && isprint(c) ) fprintf( stderr, "%5d: %5d/'%c' \"", ent, tab_prefixof(ent), c ); else fprintf( stderr, "%5d: %5d/\\%03o \"", ent, tab_prefixof(ent), c ); stack[--stack_top] = '\n'; stack[--stack_top] = '"'; /* " */ for ( ; ent != NULL; ent = (ent >= FIRST ? tab_prefixof(ent) : NULL) ) { stack_top = in_stack(tab_suffixof(ent), stack_top); } fwrite( &stack[stack_top], (size_t)1, (size_t)(STACK_SIZE - stack_top), stderr ); stack_top = STACK_SIZE; } } } int in_stack(c, stack_top) REGISTER int c, stack_top; { if ( (isascii(c) && isprint(c) && c != '\\') || c == ' ' ) { stack[--stack_top] = c; } else { switch( c ) { case '\n': stack[--stack_top] = 'n'; break; case '\t': stack[--stack_top] = 't'; break; case '\b': stack[--stack_top] = 'b'; break; case '\f': stack[--stack_top] = 'f'; break; case '\r': stack[--stack_top] = 'r'; break; case '\\': stack[--stack_top] = '\\'; break; default: stack[--stack_top] = '0' + c % 8; stack[--stack_top] = '0' + (c / 8) % 8; stack[--stack_top] = '0' + c / 64; break; } stack[--stack_top] = '\\'; } if (stack_top<0) { fprintf(stderr,"dump_tab stack overflow!!!\n"); exit(1); } return stack_top; } #else dump_tab() {} #endif /* DEBUG2 */ #endif /* DEBUG */ #endif /* METAWARE */ void writeerr() { perror ( ofname ); unlink ( ofname ); exit ( 1 ); } void copystat(ifname, ofname) char *ifname, *ofname; { struct stat statbuf; int mode; #ifndef AZTEC86 time_t timep[2]; #else unsigned long timep[2]; #endif fflush(stdout); close(fileno(stdout)); if (stat(ifname, &statbuf)) { /* Get stat on input file */ perror(ifname); return; } #ifndef PCDOS /* meddling with UNIX-style file modes */ if ((statbuf.st_mode & S_IFMT/*0170000*/) != S_IFREG/*0100000*/) { if(quiet) fprintf(stderr, "%s: ", ifname); fprintf(stderr, " -- not a regular file: unchanged"); exit_stat = 1; } else if (statbuf.st_nlink > 1) { if(quiet) fprintf(stderr, "%s: ", ifname); fprintf(stderr, " -- has %d other links: unchanged", statbuf.st_nlink - 1); exit_stat = 1; } else #endif if (exit_stat == 2 && (!force)) { /* No compression: remove file.Z */ if(!quiet) fprintf(stderr, " -- file unchanged"); } else { /* ***** Successful Compression ***** */ exit_stat = 0; #ifndef PCDOS mode = statbuf.st_mode & 07777; #else mode = statbuf.st_attr & 07777; #endif if (chmod(ofname, mode)) /* Copy modes */ perror(ofname); #ifndef PCDOS chown(ofname, statbuf.st_uid, statbuf.st_gid); /* Copy ownership */ timep[0] = statbuf.st_atime; timep[1] = statbuf.st_mtime; #else timep[0] = statbuf.st_mtime; timep[1] = statbuf.st_mtime; #endif utime(ofname, (struct utimbuf *)timep); /* Update last accessed and modified times */ /* if (unlink(ifname)) perror(ifname); */ if(!quiet) if(do_decomp == 0) fprintf(stderr, " -- compressed to %s", ofname); else fprintf(stderr, " -- decompressed to %s", ofname); return; /* Successful return */ } /* Unsuccessful return -- one of the tests failed */ if (unlink(ofname)) perror(ofname); } /* * This routine returns 1 if we are running in the foreground and stderr * is a tty. */ int foreground() { #ifndef METAWARE if(bgnd_flag) { /* background? */ return(0); } else { /* foreground */ #endif if(isatty(2)) { /* and stderr is a tty */ return(1); } else { return(0); } #ifndef METAWARE } #endif } #ifndef METAWARE void onintr (dummy) int dummy; /* to keep the compiler happy */ { (void)signal(SIGINT,SIG_IGN); unlink ( ofname ); exit ( 1 ); } void oops (dummy) /* wild pointer -- assume bad input */ int dummy; /* to keep the compiler happy */ { (void)signal(SIGSEGV,SIG_IGN); if ( do_decomp == 1 ) fprintf ( stderr, "uncompress: corrupt input\n" ); unlink ( ofname ); exit ( 1 ); } #endif void cl_block () /* table clear for block compress */ { REGISTER long int rat; checkpoint = in_count + CHECK_GAP; #ifdef DEBUG if ( debug ) { fprintf ( stderr, "count: %ld, ratio: ", in_count ); prratio ( stderr, in_count, bytes_out ); fprintf ( stderr, "\n"); } #endif /* DEBUG */ if(in_count > 0x007fffff) { /* shift will overflow */ rat = bytes_out >> 8; if(rat == 0) { /* Don't divide by zero */ rat = 0x7fffffff; } else { rat = in_count / rat; } } else { rat = (in_count << 8) / bytes_out; /* 8 fractional bits */ } if ( rat > ratio ) { ratio = rat; } else { ratio = 0; #ifdef DEBUG if(verbose) dump_tab(); /* dump string table */ #endif cl_hash ( (count_int) hsize ); free_ent = FIRST; clear_flg = 1; output ( (code_int) CLEAR ); #ifdef DEBUG if(debug) fprintf ( stderr, "clear\n" ); #endif /* DEBUG */ } } void cl_hash(hsize) /* reset code table */ REGISTER count_int hsize; { #ifdef AZTEC86 #ifdef PCDOS /* This function only in PC-DOS lib, not in MINIX lib */ memset(htab,-1, hsize * sizeof(count_int)); #else /* MINIX and all non-PC machines do it this way */ #ifndef XENIX_16 /* Normal machine */ REGISTER count_int *htab_p = htab+hsize; #else REGISTER j; REGISTER long k = hsize; REGISTER count_int *htab_p; #endif REGISTER long i; REGISTER long m1 = -1; #ifdef XENIX_16 for(j=0; j<=8 && k>=0; j++,k-=8192) { i = 8192; if(k < 8192) { i = k; } htab_p = &(htab[j][i]); i -= 16; if(i > 0) { #else i = hsize - 16; #endif do { /* might use Sys V memset(3) here */ *(htab_p-16) = m1; *(htab_p-15) = m1; *(htab_p-14) = m1; *(htab_p-13) = m1; *(htab_p-12) = m1; *(htab_p-11) = m1; *(htab_p-10) = m1; *(htab_p-9) = m1; *(htab_p-8) = m1; *(htab_p-7) = m1; *(htab_p-6) = m1; *(htab_p-5) = m1; *(htab_p-4) = m1; *(htab_p-3) = m1; *(htab_p-2) = m1; *(htab_p-1) = m1; htab_p -= 16; } while ((i -= 16) >= 0); #ifdef XENIX_16 } } #endif for ( i += 16; i > 0; i-- ) *--htab_p = m1; #endif #endif } void prratio(stream, num, den) FILE *stream; long int num; long int den; { REGISTER int q; /* Doesn't need to be long */ if(num > 214748L) { /* 2147483647/10000 */ q = (int)(num / (den / 10000L)); } else { q = (int)(10000L * num / den); /* Long calculations, though */ } if (q < 0) { putc('-', stream); q = -q; } fprintf(stream, "%d.%02d%c", q / 100, q % 100, '%'); } void version() { fprintf(stderr, "compress 4.1\n"); fprintf(stderr, "Options: "); #ifdef vax fprintf(stderr, "vax, "); #endif #ifdef _MINIX fprintf(stderr, "MINIX, "); #endif #ifdef NO_UCHAR fprintf(stderr, "NO_UCHAR, "); #endif #ifdef SIGNED_COMPARE_SLOW fprintf(stderr, "SIGNED_COMPARE_SLOW, "); #endif #ifdef XENIX_16 fprintf(stderr, "XENIX_16, "); #endif #ifdef COMPATIBLE fprintf(stderr, "COMPATIBLE, "); #endif #ifdef DEBUG fprintf(stderr, "DEBUG, "); #endif #ifdef BSD4_2 fprintf(stderr, "BSD4_2, "); #endif fprintf(stderr, "BITS = %d\n", BITS); } /* End of text from uok.UUCP:net.sources */