decode (or rather uudecode)

[R Sitze]

Not having uudecode available myself, I ended up creating my
own version.  This was used to decode pc-lisp without any 
problems.  For those who don't have uudecode, enjoy.  For
those on BSD systems, ignore.  This was NOT written for the
PC, but should be portable enough to work without to much
modification.

This is released to the public.

/*************************** CUT HERE ***********************/


#include <stdio.h>

#define	buf_size	128
char	buffer[ buf_size ];

main( argc, argv )
int	argc;
char	**argv;
{ /* main */
	extern	FILE	*fopen();
	extern	char	*fgets();

	char	*my_name;

	FILE	*in_phyle;

	FILE	*out_phyle;
	char	out_name[ buf_size ];
	int	out_mode;

	char	*mark;
	char	*ptr;

	argc--;
	my_name = *argv++;

	if( argc < 1 )
	{
		fprintf( stderr, "usage: uudecode file [ file ... ]\n" );
		exit( 1 );
	} /* if */

	while( argc-- )
	{
		if( !( in_phyle = fopen( *argv, "r" )))
			fprintf( stderr, "%s: couldn't open %s\n",
				my_name, *argv );
		else
		{
			fgets( buffer, buf_size, in_phyle );
			while( strncmp( buffer, "begin ", 6 ))
				fgets( buffer, buf_size, in_phyle );
			
			mark = buffer + 6;

			while( *mark != ' ' )	/* Get output file mode */
			{
				out_mode <<= 3;
				out_mode |= (( *mark++ ) - '0' );
			} /* while */

			mark++;			/* Get output file name */
			ptr = out_name;
			while( *mark && ( *mark != '\n' ))
				*ptr++ = *mark++;
			*ptr = '\0';

			if( !( out_phyle = fopen( out_name, "w" )))
				fprintf( stderr, "%s: couldn't open %s\n",
					my_name, out_name );
			else
			{
				printf( "decoding %s(%o)\n",
					out_name, out_mode );

				decode( in_phyle, out_phyle );

				if( fclose( out_phyle ))
				{
					fprintf( stderr,
						"%s: couldn't close %s\n",
						my_name, out_name );
					unlink( out_name );
				} /* if */
			} /* else */
			if( fclose( in_phyle ))
				fprintf( stderr, "%s: couldn't close %s\n",
					my_name, *argv );
		} /* else */
		argv++;
	} /* while */
} /* main */


decode( input, output )
FILE	*input;
FILE	*output;
{ /* decode */
	unsigned char	byte;
	unsigned char	bit;
	unsigned char	c;
	unsigned char	size;

	while( 1 )
	{
		if(( size = fgetc( input ) - ' ' ) <= 0 )
			break;

		if(( byte = fgetc( input )&95 ) >= 64 )
			byte -= ' ';
		bit = 2;

		while( size-- )
		{
			if(( c = fgetc( input )&95 ) >= 64 )
				c -= ' ';

			byte <<= bit;
			bit = 6 - bit;
			byte |= c>>bit;
			fputc( byte, output );

			bit = 8 - bit;

			byte = c;

			if(( bit == 8 ) && size )
			{
				if(( byte = fgetc( input )&95 ) >= 64 )
					byte -= ' ';
				bit = 2;
			} /* if */
		} /* while */
		fgets( buffer, buf_size, input );
	} /* while */
} /* decode */