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mirror of https://github.com/ioacademy-jikim/device_driver synced 2025-06-07 16:06:08 +00:00
device_driver/02_day/jni/rdwr_app.c
ioacademy-jikim e92d98c6d0 first sample
2015-08-19 19:26:23 +09:00

58 lines
916 B
C

#include <fcntl.h>
#include <stdio.h>
#include <string.h>
int main()
{
int fd, ret;
char buff[10];
fd = open( "/dev/mydev", O_RDONLY );
ret = read( fd, buff, sizeof buff );
buff[ret] = 0;
printf( "buff[%s], ret=%d\n", buff, ret );
close(fd);
return 0;
}
/*
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
int main()
{
int fd, ret;
int temp;
fd = open( "/dev/mydev", O_RDONLY );
ret = read( fd, &temp, sizeof temp );
printf( "temp=%d, ret=%d\n", temp, ret );
close(fd);
return 0;
}
*/
/*
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
int main()
{
int fd, ret;
char buff[] = "LED_ON";
fd = open( "/dev/mydev", O_WRONLY );
ret = write( fd, buff, strlen(buff) );
printf( "ret=%d\n", ret );
close(fd);
return 0;
}
*/
/*
#include <fcntl.h>
int main()
{
int fd;
int flag=128;
fd = open( "/dev/mydev", O_WRONLY );
write( fd, &flag, sizeof flag );
close(fd);
return 0;
}
*/