OS_File 21 (changes)
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OS SWI Calls
» OS_File
» OS_File 21
OS_ File 21
(SWI &08)
| Entry | |
|---|---|
| R0 | 21 (reason code) |
| R1 | Pointer to filename |
| R4 | Pointer to path string |
| Exit | |
|---|---|
| R0 | Object type |
| R1 | Preserved |
| R2 | Load address (without top three bytes if file is typed) |
| R3 | Execution address |
| R4 | Object length |
| R5 | Object attributes |
| R6 | Object filetype |
Use
The purpose of this call is to read catalogue information for a named file, using a path string.
Notes
R2 to R6 may be corrupted if the object is not found.
The value returned in R6 is 4096 (&1000) for images and directories, and 8192 (&2000) for applications.
A value of -1 returned in R6 can also mean:
- An untyped file, when R2 and R3 contain addresses
- No file found, when R0 = 0
See also
- Execution address
- Load address
- Object attributes
- Object type
- OS_File
- OS_File 20 (using a File$Path)
- OS_File 22 (using a path variable)
- OS_File 23 (using no path)
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