The following sample code shows how to direct somPrintf output to a file called C:\ERROR.TXT. Before enabling the replacement of SOMOutCharRoutine, the file is opened and a header is written to it.

#define INCL_DOS
#define INCL_WINWORKPLACE

#include <os2.h>
#include <io.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys\stat.h>
#include <string.h>
#include <som.h>

/* File to contain debugging error information */
static FILE *ErrorFile;

/**********************************************************************/
/*   This is the replacement for the default SOMOutCharRoutine.       */
/*   It writes the debugging information to a file on the hard drive  */
/*   instead of to stdout.                                            */
/**********************************************************************/

#pragma linkage(myCharacterOutputRoutine, system)

int SOMLINK myCharacterOutputRoutine(char chOut)
{
    fputc((int) chOut, ErrorFile);
    fflush(ErrorFile);

    return 1;   /* Indicate success */
}
   .
   .
   .

/**********************************************************************/
/*   Enable myCharacterOutputRoutine by opening the output error      */
/*   file and then changing the output character routine.             */
/**********************************************************************/

ErrorFile = fopen ("c:\\error.txt", "a");

fprintf (ErrorFile, "\nDebug information from my WPS Object\n");
fprintf (ErrorFile,   "------------------------------------\n");
setbuf  (ErrorFile, NULL);

SOM_TraceLevel  = 2;   /* Request maximum debugging information */
SOM_WarnLevel   = 2;
SOM_AssertLevel = 2;

/* All output goes to my routine after the next statement */

SOMOutCharRoutine = myCharacterOutputRoutine;