User manual

Series 3700 System Switch/Multimeter Reference Manual Section 9: Files
3700S-901-01 Rev. C / July 2008 9-5
loadscript file_io_test
-- get the current date and time
date_time = os.date('%c', os.time())
-- open the three files for writing
myfile1, myfile1_err, myfile1_errnum =
io.open('/usb1/myfile_io1', 'w')
myfile2, myfile2_err, myfile2_errnum =
io.open('/usb1/myfile_io2', 'w')
myfile3, myfile3_err, myfile3_errnum =
io.open('/usb1/myfile_io3', 'w')
if (io.type(myfile1) == 'file') then
if (io.type(myfile2) == 'file') then
if (io.type(myfile3) == 'file') then
-- make myfile1 the default output file
io.output(myfile1)
-- write some data to the default file
io.write('Using io write to myfile1 to io output\n')
io.write(date_time)
io.write('\n')
-- now write to myfile2 using descriptor rather than
io write command
myfile2:write(' file handle to write to
myfile2\n')
myfile2:write(' while myfile1 is output file for
io\n')
-- make myfile2 the default output file
io.output(myfile2)
-- write some data to the default file
io.write('Using io write to myfile2 to io output\n')
io.write(date_time)
io.write('\n')
-- now write to myfile3 using descriptor rather than
io write command
myfile3:write(' file handle to write to
myfile3\n')
myfile3:write(' while myfile2 is output file for
io\n')
-- make myfile3 the default output file
io.output(myfile3)
-- write some data to the default file
io.write('Using io write to myfile3 to io output\n')
io.write(date_time)
io.write('\n')
-- now write to myfile1 using descriptor rather than
io write command
myfile1:write(' file handle to write to
myfile1\n')
myfile1:write(' while myfile3 is output file for
io\n')
-- use the io close rather than file descriptor
close command
io.close(myfile1)
io.close(myfile2)
io.close(myfile3)
else
print('myfile3 did not open for write')
print('error string is ' .. myfile3_err)