PROMS

On Sun, 27 Nov 2011, nierveze wrote: I used to give that and the inverse as early exercises in file I/O in my [beginning] Assembly class, and as simple examples in my Data Structures and Algorithms class for unions, shifts, ANDs, file I/O Some students had difficulty grasping the concept of one input, two outputs (and vice versa, where I showed it right before merging files) Another difficulty that many students always had was processing data, such as sorting or searching, WITHOUT reading it all into memory. "Bigger than 64K? ADD RAM!; Bigger than 1M? ADD RAM!", so I made them write a sort program with NO file size limits, and one whose only size limits were the file size limits of the OS (MS-DOS FAT12 permitted files from -2147483648 to 2147483647 bytes), which was even harder. Amongst the obvious possibilities for splitting the file are: read byte write byte to file1 read byte write byte to file2 read word write byte to file1 write byte to file2 WATCH OUT FOR: some compilers want to [by default] fopen() files in "TEXT" mode, and stop when they hit char26, or other none end-of file "EOF" characters. Most such compilers have switches to over-ride without necessarily changing from fopen() to open() Surely you can reduce it to much less than 12 lines in "high level" languages! -- Grumpy Ol' Fred cisin at xenosoft.com