User manual

Section 9: Files Series 3700 System Switch/Multimeter Reference Manual
9-12 3700S-901-01 Rev. C / July 2008
file:write()
Function
Buffer data until a flush (file:flush() (on page 9-10) or io.flush()
(on page 9-12)) or close (file:close() (on page 9-10) or io.close() (on
page 9-12)) operation is performed.
NOTE Data may be lost if the file is not flushed or closed before the application
ends. A write function buffers the data until a flush or close operation is
requested.
Usage
file:write(data)
file: The descriptor of the file.
data: The data to write to the file. An arbitrary number of data values may be passed
to this command. All parameters must be either strings or numbers.
Remarks
Any error encountered is logged to the error queue.
This command is not remotely accessible.
io.close()
Function
Closes the specified file.
Usage
io.close(file)
file: A file descriptor to flush and close
Remarks
This command is equivalent to file:close() (on page 9-10).
io.flush()
Function
Flush the buffered data for the current output file.
Usage
io.flush()
Remarks
Use this command to flush data written to the current default file by file:write()
(on page 9-11) or io.write() (on page 9-14). Using this command removes the
need to close a file after writing to it and allows it to be left open to write more data.
Data may be lost if the file is not closed or flushed before an application ends. To
prevent the loss of data if there is going to be a time delay before more data is written
when you want to keep file open and not close it, flush the file after writing to it.
io.input()
Function
Assigns a previously opened file, or opens a new file, as the default input file.
Usage
io.input(filein)
fileout = io.input()
filein: A file descriptor to assign or the path of a file to open as the default input file.
The path may be absolute or relative to the current working directory. This parameter
is optional; if absent, the command returns the absolute path to the current default
input file (fileout).
fileout: The absolute path to the default input file.