SPRUI04F july 2015 – april 2023
#include <stdio.h>
#include <file.h>
#include "mydevice.h"
void main()
{
add_device("mydevice", _MSA,
MYDEVICE_open, MYDEVICE_close,
MYDEVICE_read, MYDEVICE_write,
MYDEVICE_lseek, MYDEVICE_unlink, MYDEVICE_rename);
/*-----------------------------------------------------------------------*/
/* Re-open stderr as a MYDEVICE file */
/*-----------------------------------------------------------------------*/
if (!freopen("mydevice:stderrfile", "w", stderr))
{
puts("Failed to freopen stderr");
exit(EXIT_FAILURE);
}
/*-----------------------------------------------------------------------*/
/* stderr should not be fully buffered; we want errors to be seen as */
/* soon as possible. Normally stderr is line-buffered, but this example */
/* does not buffer stderr at all. This means that there will be one call */
/* to write() for each character in the message. */
/*-----------------------------------------------------------------------*/
if (setvbuf(stderr, NULL, _IONBF, 0))
{
puts("Failed to setvbuf stderr");
exit(EXIT_FAILURE);
}
/*-----------------------------------------------------------------------*/
/* Try it out! */
/*-----------------------------------------------------------------------*/
printf("This goes to stdout\n");
fprintf(stderr, "This goes to stderr\n"); }