FREADDIR
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| Syntax | Parameters | Operation Notes | Condition Codes |
Syntax
I16V UDS I16V I32V
FREADDIR (filenum, buffer, length, lrecnum);
Parameters
- filenum
16-bit signed integer by value (required)
Passes the file number of the file to be read.
- buffer
user-defined structure (required)
Returns the record that was read. This structure should be large enough to hold all of the information to be transferred.
- length
16-bit signed integer by value (required)
Passes the number of halfwords or bytes to be transferred. If this value is positive, it signifies halfwords. A negative value indictates a transfer in bytes. If zero, no transfer occurs.
If length is less than the size of the logical record, only the first length halfwords or bytes are read from the record. If length is larger than the size of the logical record, the transfer is limited to the length of the logical record.
- lrecnum
32-bit signed integer by value (required)
Indicates the relative physical record number to which the physical pointer is positioned. Physical record numbering for fixed-length records starts with zero or one, as specified when the file was built.
Operation Notes
This intrinsic reads the advance flag. It sets only the physical pointer to the appropriate record. When its function is completed, it sets the advance flag to TRUE. This intrinsic is different from the FREAD intrinsic. The FREAD intrinsic reads only the record already pointed to by the logical record pointer. FREADDIR inputs the specified logical record. If the record is inactive, the contents of the inactive record are transmitted and a CCE is returned. There is no indication of the block containing some inactive records. (FCHECK returns a nonzero error number to distinguish active and inactive records.)
Condition Codes
- CCE
Request granted. The information was read.
- CCG
Request denied. End-of-data was encountered.
- CCL
Request denied. The information was not read; an error occurred.
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FREADC |
FREADLABEL |