pSOSystem System Calls - Read

ead_vol pHILE+ System Calls
Error Codes
Notes
See Also
Hex Mnemonic Description
0x200A E_DMOUNT Volume not mounted.
0x2025 E_IDN Illegal device name.
0x2050 E_BADNFS NFS volume; illegal operation.
1. If index is larger than the volume's block size, the read begins in a subsequent
block. For example, on a volume with a 1024-byte block size, a read of block 5,
index 1224, is the same as a read block 6, index 200.
2. CD-ROM volumes generally use a 2K block size.
3. read_vol() does not check for the end of the volume, so blocks beyond the
specified volume size can be read if they physically exist.
4. If the requested data includes either entire blocks or a contiguous sequence of
blocks and if such blocks are not already in the buffer cache, the pHILE+ file
system manager reads blocks directly into the buffer (without going through the
buffer cache). Therefore, read_vol() executes more efficiently when bcount
and index are equal to integral multiples of blocks.
write_vol
2-100 pSOSystem System Calls