FREADLABEL
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| E0300 Edition 4 ♥ | |
| E0394 Edition 3 |
| Syntax | Parameters | Operation Notes | Condition Codes |
Syntax
I16V UDS I16V I16V
FREADLABEL (filenum, buffer, length, labelid);
Parameters
- filenum
16-bit signed integer by value (required)
Passes the file number of the file whose label is to be read.
- buffer
user-defined structure (required)
Returns the label that was read. This structure must be large enough to hold the number of halfwords specified by length.
- length
16-bit signed integer by value (optional)
Passes the number of halfwords to be transferred from the label. This field must not be greater than 128 halfwords.
Default: 128 halfwords
- labelid
16-bit signed integer by value (optional)
Passes the label number. (The first label is numbered zero.)
Default: Zero
Operation Notes
When a disk file is opened, user labels can be read from it, or written to it, in any order, at any time, regardless of access capabilities to the rest of the file. A disk file can have as many as 254 128-halfword user-defined labels.
Condition Codes
- CCE
Request granted. The label was read.
- CCG
Request denied. A label was referenced beyond the last label written on the file.
- CCL
Request denied. The label was not read; an error occurred.
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FREADDIR |
FREMOVE |