ship.c

Ship version 1.7--utility to encode, split, and mail binary data and reconstruct the data at the ot

   treated like the second member of the pair.  You're probably
   wondering why.  The first pair is for compatibility with an
   earlier version of ship that used ! for the base 85 zero digit.
   However, there exist ASCII-EBCDIC translation tables that don't
   know about exclamation marks.  The second set has mysterious
   historical origins that are best left unspoken ... */
unsigned char aliases[] = {'!','{','|','+',0};

/* Inverse of safe[], filled in by mkinv() */
unsigned char invsafe[256];

/* Table of CRC-32's of all single byte values (made by makecrc.c) */
ulg crctab[] = {
  0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
  0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
  0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
  0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
  0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
  0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
  0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
  0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
  0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
  0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
  0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
  0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
  0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
  0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
  0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
  0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
  0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
  0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
  0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
  0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
  0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
  0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
  0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
  0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
  0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
  0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
  0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
  0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
  0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
  0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
  0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
  0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
  0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
  0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
  0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
  0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
  0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
  0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
  0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
  0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
  0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
  0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
  0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
  0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
  0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
  0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
  0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
  0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
  0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
  0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
  0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
  0x2d02ef8dL
};

/* Macro to update the CRC shift register one byte at a time */
#define CRC(c,b) (crctab[((int)(c)^(int)(b))&0xff]^((c)>>8))


char *errname = "ship error";
char *warname = "ship warning";

void err(n, m)
int n;                  /* error number */
char *m;                /* additional error information */
{
  if (n == SE_FIND || n == SE_FULL)
    perror(errname);
  fputs(errname, stderr);
  fputs(": ", stderr);
  fputs(errors[n - 1], stderr);
  fputs(m, stderr);
  putc('\n', stderr);
  if (*mname)
    unlink(mname);
#ifdef VMS
  exit(0);
#else /* !VMS */
  exit(n);
#endif /* ?VMS */
}


cfile *chook(f)
FILE *f;                /* file stream */
/* Inherit the file stream structure and add a CRC and buffer for appending
   a CRC on reads and checking the CRC on writes.  Return a pointer to the
   cfile structure, or NULL if the malloc() failed.  Also, if MSDOS, set the
   file mode to binary to avoid LF<->CRLF conversions. */
{
  cfile *c;             /* allocated cfile structure */

#if defined(MSDOS) && !defined(ATARI_ST)
  /* Set file mode to binary for MSDOS systems */
  setmode(fileno(f), O_BINARY);
#endif /* MSDOS */

  /* Allocate and fill structure */
  if ((c = (cfile *)malloc(sizeof(cfile))) != NULL)
  {
    c->f = f;                           /* file stream */
    c->b = 0;                           /* empty fifo (for output) */
    c->c = 0xffffffffL;                 /* preload CRC register */
    c->n = 0;                           /* fifo is empty (output) or */
  }                                     /*  no CRC bytes given (input) */
  return c;
}



/* cgetc(x)--like getc(f), but appends a 32-bit CRC to the end of the stream.
   Return the byte read (the last four of which will be the CRC) or EOF. */
#define cgete(x) (x->n==4?EOF:(x->c=x->n++?x->c>>8:~x->c,(int)x->c&0xff))
#define cgetc(x) (x->n==0&&(b=getc(x->f))!=EOF?(ccnt++,x->c=CRC(x->c,b),b):cgete(c))


/* cputc(d,x)--like putc(d,f), but delays four bytes and computes a CRC.
   x is a cfile *, and d is expected to be an ulg. */
#define cputf(x) (int)(x->c=CRC(x->c,x->b),putc((int)x->b&0xff,x->f),ccnt++)
#define cputc(d,x) (x->n!=4?x->n++:cputf(x),x->b=(x->b>>8)+((ulg)(d)<<24))


char *nopath(p)
char *p;                /* full file name */
/* Extract just the name of file--remove and subdirectories or devices */
{
#ifdef MSDOS
  char *q = "/\\:";     /* MSDOS delimiters */
#else /* !MSDOS */
#ifdef VMS
  char *q = "]:";       /* VMS delimiters */
#else /* !VMS */
  char *q = "/";        /* Unix delimiter */
#endif /* ?VMS */
#endif /* ?MSDOS */
  char *r;              /* result of strrchr() */

  while (*q)
    if ((r = strrchr(p, *q++)) != NULL)
      p = r + 1;
  return p;
}


void newship()
/* Open up a new ship file to write to */
{
  int i;                /* scans down name to increment */

  for (i = 7; i > 3; i--)
    if (++sname[i] > '9')
      sname[i] = '0';
    else
      break;
  if (i == 3)
    err(SE_MANY, "");
  if ((sfile = fopen(mail ? mktemp(strcpy(mname, TMPNAME)) : sname,
                     "w")) == NULL)
    err(SE_FULL, mail ? mname : sname);
  slns = 0;
}


void endship(e)
int e;          /* true if ending the last ship file */
/* Finish off current ship file */
{
  char *s;              /* malloc'd space for mail command */

  if (ferror(sfile) || fclose(sfile))
    err(SE_FULL, mail ? mname : sname);
  if (mail)
  {
    if ((s = malloc(strlen(MAILCMD)- 5*2 + strlen(mprefix) + strlen(sname) +
                    (e ? 7 : 0) + strlen(mdest) + strlen(mname) + 1)) == NULL)
      err(SE_MEM, "");
#ifdef VMS
    sprintf(s, MAILCMD, mname, mprefix, sname, e ? " (last)" : "", mdest);
    if (!system(s))             /* this string fits on one line */
      err(SE_MAIL, "system() call is not supported on this machine");
#else /* !VMS */
    sprintf(s, MAILCMD, mprefix, sname, e ? " (last)" : "", mdest, mname);
    if (system(s))
      err(SE_MAIL, s);
#endif /* ?VMS */
    free((voidp *)s);
    unlink(mname);
    *mname = 0;
  }
}


void newline(p)
char *p;                /* name of the input file */
/* Add a new line inside a ship file, possibly cut the file */
{
  putc('\n', sfile);
  slns++;
  if (slmax && slns >= slmax - 2)
  {
    putc('$', sfile);
    if (fast)
      fputs(" f", sfile);
    fputs("\nmore\n", sfile);
    endship(0);
    newship();
    fprintf(sfile, "$%s\ncont %lu %s\n", fast ? " f" : "", ccnt, nopath(p));
    slns += 2;
  }
}


/* Macro to avoid leading dots.  It assumes i==0 at the beginning of a line
   and that b is an available int.  c is only evaluated once. */
#define sputc(c,f) (i==0?((b=(c))=='.'?putc(' ',f):0,putc(b,f)):putc(c,f))


void ship(p, f)
char *p;                /* name of the input file */
FILE *f;                /* input file */
/* Encode the binary file f. */
{
  int b;                /* character just read */
  cfile *c;             /* checked file stream */
  int i;                /* how much is written on line so far */
  int j;                /* how much is in bit buffer */

  /* Set up output file if needed */
  if ((mail || slmax) && sfile == stdout)
  {
    strcpy(sname, "part0000");
    newship();
  }

  /* Write header */
  if ((c = chook(f)) == NULL)
    err(SE_MEM, "");
  ccnt = 0;
  if (slmax && slns >= slmax - 5) 
  {
    endship(0);
    newship();
  }
  fprintf(sfile, "$%s\nship %s\n", fast ? " f" : "", nopath(p));
  slns += 2;

  /* Encode the file, writing to sfile */
  if (fast)
  {
    int d;              /* accumulates bits (never more than 14) */

    d = j = i = 0;
    while ((b = cgetc(c)) != EOF)
    {
      d |= b << j;
      j += 8;
      if ((d & 0x3f) >= LOWSZ)
      {
        sputc((int)(safe[(d & 0x3f) + LOWSZ]), sfile);
        d >>= 6;
        j -= 6;
      }
      else
      {
        sputc((int)(safe[(d & 0x3f) + (d & 0x40 ? LOWSZ : 0)]), sfile);
        d >>= 7;
        j -= 7;
      }
      if (++i == 79)
      {
        newline(p);
        i = 0;
      }
      if (j >= 6 && (d & 0x3f) >= LOWSZ)
      {
        sputc((int)(safe[(d & 0x3f) + LOWSZ]), sfile);
        d >>= 6;
        j -= 6;
        if (++i == 79)
        {
          newline(p);
          i = 0;
        }
      }
      else if (j >= 7)
      {
        sputc((int)(safe[(d & 0x3f) + (d & 0x40 ? LOWSZ : 0)]), sfile);
        d >>= 7;
        j -= 7;
        if (++i == 79)
        {
          newline(p);
          i = 0;
        }
      }
    }
    free((voidp *)c);

    /* Write leftover bits */
    if (j)
    {
      sputc((int)(safe[d + (d < LOWSZ ? 0 : LOWSZ)]), sfile);
      putc('\n', sfile);
      slns++;
    }
    else if (i)
    {
      putc('\n', sfile);
      slns++;
    }
  }
  else
  {
    ulg d;              /* accumulates bytes */

    d = j = i = 0;
    while ((b = cgetc(c)) != EOF)
    {
      d += ((ulg)b) << j;
      if ((j += 8) == 32)
      {
        sputc((int)(safe[(int)(d % 85)]), sfile);  d /= 85;
        putc((int)(safe[(int)(d % 85)]), sfile);  d /= 85;
        putc((int)(safe[(int)(d % 85)]), sfile);  d /= 85;
        putc((int)(safe[(int)(d % 85)]), sfile);  d /= 85;
        putc((int)(safe[(int)d]), sfile);
        if (++i == 15)                  /* each line is <= 75 characters */
        {
          newline(p);
          i = 0;
        }
        d = j = 0;
      }
    }
    free((voidp *)c);
  
    /* Write leftover data */
    if (j)
    {
      j >>= 3;
      sputc((int)(safe[(int)(d % 85)]), sfile);
      while (j--)
      {
        d /= 85;
        putc((int)(safe[(int)(d % 85)]), sfile);
      }
      putc('\n', sfile);
      slns++;
    }
    else if (i)
    {
      putc('\n', sfile);
      slns++;
    }
  }
  putc('$', sfile);
  if (fast)
    fputs(" f", sfile);
  fputs("\nend\n", sfile);
  slns += 2;
  if (ferror(sfile) || fflush(sfile))
    err(SE_FULL, mail ? mname : sname);
  if (noisy)
    fprintf(stderr, "%s shipped\n", p);
}


void mkinv()
/* Build invsafe[], the inverse of safe[]. */
{
  int i;

  for (i = 0; i < 256; i++)
    invsafe[i] = 127;
  for (i = 0; i < sizeof(safe); i++)
    invsafe[safe[i]] = (char)i;
  for (i = 0; aliases[i]; i += 2)
    invsafe[aliases[i]] = invsafe[aliases[i + 1]];
}


unsigned int decb;      /* bit buffer for decode */
unsigned int decn;      /* number of bits in decb */

void decode(s, c)
unsigned char *s;       /* data to decode */
cfile *c;               /* binary output file */
/* Decode s, a string of base 85 digits or, if fast is true, a string of safe
   characters generated arithmetically, into its binary equivalent, writing
   the result to c, using cputc(). */
{
  int b;                /* state of line loop, next character */
  int k;                /* counts bits or digits read */
  /* powers of 85 table for decoding */
  static ulg m[] = {1L,85L,85L*85L,85L*85L*85L,85L*85L*85L*85L};

  if (fast)
  {
    unsigned int d;     /* disperses bits */

    d = decb;
    k = decn;
    while ((b = *s++) != 0)
      if ((b = invsafe[b]) < sizeof(safe))
      {
        if (b < LOWSZ)
        {
          d |= b << k;
          k += 7;
        }
        else if ((b -= LOWSZ) < LOWSZ)
        {
          d |= (b + 0x40) << k;
          k += 7;
        }
        else
        {
          d |= b << k;
          k += 6;
        }
        if (k >= 8)
        {
          cputc(d, c);
          d >>= 8;
          k -= 8;
        }
      }
    decb = d;
    decn = k;
  }
  else