utoddl@uncecs.edu (Todd M. Lewis) (10/27/89)
Hello, net:
A friend and I are working on a program which will end up
copying lots of files to lots of floppies. We need to know how to
calculate how many blocks a group of files will use on a floppy,
including the overhead for directory entries, etc. We would like
the user to be able to select a bunch of files and have the program
be able to tell
1) if the files will fit on a given floppy,
2) how many blocks will be used, and
3) how many blocks will be left.
(Ok, so 3 should be easy if you know 1 and two.) So how
does one (or in our case, two) go about calculating such things.
Your help is greatly appreciated.
_____
| Todd M. Lewis Disclaimer: If you want my employer's
||\/| utoddl@ecsvax.uncecs.edu ideas, you'll have to
|| || utoddl@ecsvax.bitnet _buy_ them.
|___ ("Prgrms wtht cmmnts r lk sntncs wtht vwls." --TML)ccplumb@rose.waterloo.edu (Colin Plumb) (10/27/89)
In article <1989Oct26.190532.3479@uncecs.edu> utoddl@uncecs.edu (Todd M. Lewis) writes: > 1) if the files will fit on a given floppy, > 2) how many blocks will be used, and > 3) how many blocks will be left. > >(Ok, so 3 should be easy if you know 1 and two.) So how >does one (or in our case, two) go about calculating such things. >Your help is greatly appreciated. This is easily drived from the information in the AmigaDOS Technical Reference Manual, which you probably have. To compute the number of blocks a file will take up, divide its size in bytes by 488 (for OFS) or 512 (for FFS). Then add 1/72 of this number (round up, and there is always at least 1) blocks of overhead. Files from 0 to 72 blocks long have 1 block of overhead; files from 73 to 144 blocks long have two blocks of overhead, etc. A directory is 1 block, period. A floppy also usually contains two boot blocks and one block of bitmap. On top of that, just count the root directory as a normal directory and that should be all you need. A blank floppy has 880*2 = 1760 blocks free. 1756 after allocating the boot blocks, bitmap block, and root directory. -- -Colin