- [x] file operations
  - [x] write to file (at index)
  - [x] read file
- [x] a tape type - representing a file?
- [x] a record type - x1,x2,x3,x4,x5
  - [x] comparing records
- [x] buffer quick sort
- [x] configuration
  - [x] cmd args - man getopts
- [x] file input
- [ ] keyboard input
- [x] stage 1
  - [x] reading chunks
  - [x] sorting
  - [x] writing runs
- [ ] stage 2
  - [ ] reading runs
  - [ ] multiway merge
  - [ ] writing larger runs
  - [ ] repeat untill done
- [ ] testing
- [ ] report