Replacing Carriage Return & Line Feeds with Other Characters

The information in this article applies to:

• Microsoft Visual FoxPro for Windows, version 3.0
• Microsoft FoxPro for Windows, version 2.6a

SUMMARY

This article shows by example how to have a program process a file to replace carriage returns and line feeds with a double dollar sign. You can modify the code to use a character other than the double dollar sign by replacing the double dollar sign ASCII value (CHR(36)) with some other appropriate ASCII value. The code in this article also demonstrates how to use low level file functions.

MORE INFORMATION

The following program takes two parameters:

• The file that needs carriage returns and line feeds removed (file1).
• The file name to write to (file2).

Sample Code

PARAMETER file1,file2 PRIVATE fhandle_in,fhandle_out,fisize,inchar

fhandle_in=FOPEN(file1,2)

IF (fhandle_in#-1)                 && open read/write buffered
   fhandle_out=FCREATE(file2)      && default read/write
   fisize=FSEEK(fhandle_in,0,2)    && get the size of the file
   =FSEEK(fhandle_in,0,0)          && reposition pointer to beginning of
                                   && file
   x=1
   DO WHILE (x<=fisize)            && process the whole file
      inchar=FREAD(fhandle_in,1)   && read 1 byte at a time
      IF ((inchar = CHR(13)) .OR. ;
          (inchar = CHR(10)))
          *** change the replacement character '$$'
          *** by changing the CHR value below
         =FWRITE(fhandle_out,CHR(36)) && replace crlf with $$
      ELSE
         =FWRITE(fhandle_out,inchar)  && write the character to file
      ENDIF
      x=x+1                           && increment the variable
   ENDDO
   =FCLOSE(fhandle_in)                && release the file handle to close
                                      && file1
   =FCLOSE(fhandle_out)               && release the file handle to close
                                      && file2
   MODIFY FILE &file2                 && opens the target file for viewing
ELSE
   RETURN .F.                         && could not open the input file

How to Use the Sample Code

To demonstrate the code example, copy it into a new program file, and save it as TEST.PRG. Then from the Command Window, type:

   Do TEST.PRG with "C:\TEST.TXT", "C:\TEST1.TXT"

Here C:\TEST.TXT is the file that needs carriage returns and line feeds removed, and C:\TEST1.TXT is the name of the new file.