.help zsttbf May84 "System Interface"
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NAME
zsttbf -- get file status for a binary file
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SYNOPSIS
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zsttbf (chan, param, lvalue)

int	chan			# OS channel assigned to file
int	param			# parameter to be returned
long	lvalue			# return value of parameter
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DESCRIPTION
The \fBzsttbf\fR primitive is used to obtain file, device, and machine
dependent information for the binary file (and device) connected to the
channel \fIchan\fR.  The integer argument \fIparam\fR selects the parameter
to be returned; a separate call is required to access each parameter.
.ls
.ls FSTT_BLKSIZE        (=1)
If the file is a blocked file, the size of a device block in bytes.
A streaming file is indicated by a device block size of zero.
Variable size records may be read from or written to a streaming file.
A blocked file with a block size of one byte denotes a randomly addressable
file with no blocking restrictions.
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.ls FSTT_FILSIZE        (=2)
The current file size in machine bytes.  FIO uses this parameter when
appending to blocked binary files.  The file size is undefined for streaming
files.  FIO will ask for this parameter once when the file is opened,
and thereafter FIO will keep track of the file size internally.
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.ls FSTT_OPTBUFSIZE     (=3)
The optimum, i.e. default, buffer size for a FIO file buffer for "regular"
i/o.  Should be an integral multiple of the device block size.
FIO will create a larger or smaller buffer if advised that i/o is to be
abnormally sequential or random in nature.  The optimum transfer size is
expected to be both device and machine dependent.
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.ls FSTT_MAXBUFSIZE     (=4)
The maximum size of a FIO file buffer, i.e., the maximum permissible
transfer size.  If there is no maximum value zero is returned.
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RETURN VALUE
ERR is returned (coerced into a long integer) if \fIchan\fR or \fIparam\fR
is illegal.  The legal \fIlvalues\fR are all nonnegative integer values.
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SEE ALSO
zfiobf
.endhelp