FREAD( ) Function

  • [アーティクル]

Returns a specified number of bytes from a file opened with a low-level function.

FREAD(nFileHandle, nBytes)

Return Values

Character

Parameters

  • nFileHandle
    Specifies the file handle number for the file from which FREAD( ) returns data. You can obtain nFileHandle from the return value of successful FOPEN( ) or FCREATE( ) statements .
  • nBytes
    Specifies the number of bytes returned by FREAD( ). FREAD( ) returns data starting from the current file pointer position and continues until it returns nBytes bytes or until it encounters the end of the file.

Example

The following example uses FREAD( ) to display the contents of a file. If the file is empty**,** a message is displayed.

* TEST.TXT must exist -- you can create this file
* using Notepad.

Local gnFileHandle,nSize,cString
gnFileHandle = FOPEN("test.txt")
* Seek to end of file to determine the number of bytes in the file
nSize =  FSEEK(gnFileHandle, 0, 2)     && Move pointer to EOF
IF nSize <= 0
 * If the file is empty, display an error message
 WAIT WINDOW "This file is empty!" NOWAIT
ELSE
 * If file is not empty, the program stores its contents
 * in memory, then displays the text on the main Visual FoxPro window
 = FSEEK(gnFileHandle, 0, 0)      && Move pointer to BOF
 cString = FREAD(gnFileHandle, nSize)
 ? cString
ENDIF
= FCLOSE(gnFileHandle)         && Close the file

See Also

FCHSIZE( ) | FCLOSE( ) | FCREATE( ) | FEOF( ) | FFLUSH( ) | FGETS( ) | FILETOSTR( ) | FOPEN( ) | FPUTS( ) | FSEEK( ) | FWRITE( )