gistfile1.txt

1)
23=0x17
23=027

2)
/* C code */
void fizzbuzz()
{
    int i = 1;
    while ( i <= 100 )
    {
        if ( i % 15 == 0 ) puts( "fizzbuzz" );
        else if ( i % 3 == 0 ) puts( "fizz" );
        else if ( i % 5 == 0 ) puts( "buzz" );
        else printf( "%i\n", i );
        i++;
    }
}

3)
 1. match numbers in scientific notation
 2. match beginning of a line
 3. match either "+" or "-", if it is there. if it is not, still try to match
 4. match "e" or "E", that may or may not be followed by either "+" or "-" and 
    one or more decimal numerals
 5. the questionmark denotes an optional match, prefering to match
 
4)
/* FindSource
find all directory entries of a directory, whose name consists of the string, 
which is given in the argument base, followed by a string from a predefined list  
for the filenamesuffix. entries, that are deeper in the list of suffixes, take
precedence over others.
*/
String FindSource( String base, String dir )
{
    DIR * dirp = opendir( dir );        // open a directory handler
    String result;			// tmp pointer to the structure to return
    
    for ( int i = NS-1; i >= 0; --i )   // iterate list of suffixes, top2bottom
    {
        String tmp = base + suffix[i];  // build a filename from base and
                                        //  one of the listentries
        
        //iterate over the entries in the directory
        for ( dirent *de = readdir( dirp ); de != NULL; de = readdir( dirp ) )
        {
            if ( tmp == de->d_name )    // when we have a match, return it
            {
                result = tmp;
                break;
            }
        }
        if (result) break;		// we have a match, return it
        rewinddir( dirp );		// reset the directory entry pointer
    }
    
    closedir( dirp );			// close the directory handler
    return result;
}

5)
unsigned fac_sub(unsigned n, unsigned res)
{
    if ( n != 1 )
    {   if ( res < ( res = n * res ) )
        {
            fprintf(stderr, "carry detected");
            return 0;
        }
        res = faculty( --n, res );
    }
    return res;
}

unsigned fac( unsigned n )
{
    if ( n ) return fac_sub( n, 1 );
    return 0;
}