#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 */
/* doesn't 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"); }
NOTE
Use Unique Function Names
The function names open, read, write, close, lseek, rename, and unlink are used by the low-level routines. Use other names for the device-level functions that you write.
Use the low-level function add_device() to add your device to the device_table. The device table is a statically defined array that supports n devices, where n is defined by the macro _NDEVICE found in stdio.h/cstdio.
The first entry in the device table is predefined to be the host device on which the debugger is running. The low-level routine add_device() finds the first empty position in the device table and initializes the device fields with the passed-in arguments. For a complete description, see the add_device function.