fileReadRecord

Overview

Data is entered into a file with the fileWrite, fwriteln, or fdisplay functions, however, records are not actually committed to the file until the file is closed. Thus, attempting to read a record immediately after a fileWrite or fdisplay will result in an error. In order to verify records that have been written, it is necessary to close the file and save the file (fileClose with an option argument equal to 1) . The file can then be re-opened and read with the fileReadRecord function.

For example here is example code which writes a file and then reads records from it.

(writeTestFile)

(readTestFile)

Where readTestFile is defined as follows.

(defun readTestFile()

    vars:(n N aEOF aBuffer (aLine ""))

    (setq aFile (fileOpen aFileName 0 0))

    (setq aBuffer (fileReadRecord aFile))

    (while (<> aLine #void) do

      (setq aLine (fileReadRecord aFile aBuffer))

      (writeln aLine)

    ) ; end of while

    (setq aFile (fileClose aFile 1))

    true)

And where writeTestFile is defined as follows.

(defun writeTestFile()

    vars:(n N)

    (setq aFile (fileOpen aFileName 1 0))

    (loop for n from 0 until 10 do

      (fileWriteln aFile n #\tab "some text" )

    ) ; end of loop

    (setq aFile (fileClose aFile 1))

    true)

;;Main Code

(writeTestFile)

(readTestFile)

Usage

Syntax

Examples

Argument Types