I$Dup
From NitrOS-9
| Duplicate Path | Returns a synonymous path number |
| OS9 I$Dup 103F 82 |
Entry Conditions
A old path number (number of path to duplicate)
Exit Conditions
A new path number (if no error)
Error Output
CC carry set on error
B error code, if any
Additional Information
- The Duplicate Path returns another, synonymous path number for the file or device specified by the old path number.
- The shell uses the Duplicate Path call when it redirects I/O.
- System calls can use either path number (old or new) to operate on the same file or device.
- Makes sure that no more than one process is performing I/O on any one path at the same time. Concurrent I/O on the same path can cause unpredictable results with RBF files.
- The I$Dup call always uses the lowest available path number. This lets you manipulate standard I/O paths to contain any desired paths.
