45 lines
884 B
C
45 lines
884 B
C
#include "monitor_user.h"
|
|
#include <fcntl.h>
|
|
#include <stdio.h>
|
|
#include <sys/ioctl.h>
|
|
#include <unistd.h>
|
|
|
|
#define DEVICE "/dev/variable_monitor"
|
|
int file_desc = -1;
|
|
|
|
/// @brief start watch
|
|
/// @param w_arg
|
|
/// @return 0 means success, other means fail
|
|
int start_watch(watch_arg w_arg) {
|
|
if (file_desc < 0) {
|
|
file_desc = open(DEVICE, 0);
|
|
}
|
|
if (file_desc < 0) {
|
|
printf("Can't open device file: %s\n", DEVICE);
|
|
return -1;
|
|
}
|
|
|
|
if (ioctl(file_desc, 0, &w_arg) < 0) {
|
|
printf("ioctl failed\n");
|
|
close(file_desc);
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/// @brief cancel watch
|
|
/// @return 0 means success, other means fail
|
|
int cancel_watch() {
|
|
if (file_desc < 0) {
|
|
file_desc = open(DEVICE, 0);
|
|
}
|
|
if (file_desc < 0) {
|
|
printf("Device not open: %s,%d \n", DEVICE, file_desc);
|
|
return file_desc;
|
|
}
|
|
|
|
close(file_desc);
|
|
file_desc = -1;
|
|
return 0;
|
|
}
|