/* This is a junky piece of C designed to take a uuencoded file
   as the first parameter and decode it into the file given as
   the second parameter. there is no error checking or other
   warning if it encounters a problem. The purpose of this
   program is to act as a simple bootstrap to enable the initial
   transfer of a file to allow more advanced binary transfers.

   In particular, note that the first line of the file to be
   decoded should be the 'begin' line produced by a uuencode.

   This code (for what it is worth) is Copyright 1990, by
   David R. Evans, NQ0I.

*/

#define byte unsigned char

#include <stdio.h>
#include <string.h>

main(argc, argv)
int argc;
char** argv;
{ char line[100];
  FILE *infile, *outfile;

/* open the files */
  infile = fopen(argv[1], "r");
  outfile = fopen(argv[2], "w");

/* skip the first (begin) line */
  fgets(line, 100, infile);

/* decode the remainder of the file */
  while (fgets(line, 100, infile), strncmp(line, "end", 3))
  { int n_to_write, n_to_read, n_reads, n, m;
    byte b[4], out[3];

    n_to_write = (int)line[0] - 32;
    n_to_read = ((n_to_write + 2) / 3) * 4;
    if(strlen(line) - 2 < n_to_read)	/* EOF apparently */
      n_to_read = 0;
    n_reads = n_to_read / 4;
    for (n = 0; n < n_reads; n++)
    { for (m = 0; m < 4; m++)
        b[m] = line[1 + 4 * n + m] - 32;

/* now do the actual decode */
      out[0] = (b[0] << 2) | ((b[1] & 0x30) >> 4);
      out[1] = ((b[1] & 0x0f) << 4) | ((b[2] & 0x3c) >> 2);
      out[2] = ((b[2] & 0x03) << 6) | (b[3]);
      if(n_to_write > 3)
	for (m = 0; m < 3; m++)
	  fputc(out[m], outfile);
      else
	for (m = 0; m < n_to_write; m++)
	  fputc(out[m], outfile);
      n_to_write -= m;
    }
  }
  fflush(outfile);
}