root / rfid-web / main.c @ f3599378
History | View | Annotate | Download (1.62 KB)
1 |
#include <sys/types.h> |
---|---|
2 |
#include <sys/stat.h> |
3 |
#include <fcntl.h> |
4 |
#include <termios.h> |
5 |
#include <unistd.h> |
6 |
#include <stdio.h> |
7 |
#include <stdarg.h> |
8 |
#include <stdlib.h> |
9 |
#include <string.h> |
10 |
|
11 |
#define RFID_OK 1 |
12 |
static char read_cmd[] = {'!', 'R', 'W', 1, 32}; |
13 |
static int serno; |
14 |
|
15 |
void init_tty(int fd) { |
16 |
struct termios ios;
|
17 |
bzero(&ios, sizeof(ios));
|
18 |
ios.c_cflag = B9600 | CS8 | CREAD; |
19 |
tcsetattr(fd, TCSAFLUSH, &ios); |
20 |
} |
21 |
|
22 |
int bswap(int x) { |
23 |
return ((x&0xff) << 24) | ((x&0xff00) << 8) |
24 |
| ((x>>8) & 0xff00) | ((x>>24) & 0xff); |
25 |
} |
26 |
|
27 |
void read_all(int fd, void *buf, int n) { |
28 |
int nread;
|
29 |
while (n > 0) { |
30 |
nread = read(fd, buf, n); |
31 |
buf += nread; |
32 |
n -= nread; |
33 |
usleep(10000);
|
34 |
} |
35 |
} |
36 |
|
37 |
void write_all(int fd, void *buf, int n) { |
38 |
int nwritten;
|
39 |
while (n > 0) { |
40 |
nwritten = write(fd, buf, n); |
41 |
buf += nwritten; |
42 |
n -= nwritten; |
43 |
usleep(10000);
|
44 |
} |
45 |
} |
46 |
|
47 |
void fail_error(const char *error, ...) { |
48 |
va_list args; |
49 |
va_start(args, error); |
50 |
printf("Status: 500 Internal Server Error\n");
|
51 |
printf("Content-type: text/plain\n\n");
|
52 |
vprintf(error, args); |
53 |
va_end(args); |
54 |
exit(0);
|
55 |
} |
56 |
|
57 |
int main(int argc, char **argv) { |
58 |
int fd;
|
59 |
char status;
|
60 |
|
61 |
fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY);
|
62 |
if (fd < 0) |
63 |
fail_error("Could not open /dev/ttyUSB0\n");
|
64 |
|
65 |
init_tty(fd); |
66 |
tcflush(fd, TCIFLUSH); |
67 |
write_all(fd, read_cmd, sizeof(read_cmd));
|
68 |
|
69 |
read_all(fd, &status, 1);
|
70 |
if (status == RFID_OK) {
|
71 |
read_all(fd, &serno, 4);
|
72 |
serno = bswap(serno); |
73 |
printf("Content-type: text/plain\n\n");
|
74 |
printf("%08x\n", serno);
|
75 |
} else {
|
76 |
fail_error("Reader gave error %d\n", (int)(unsigned char)status); |
77 |
} |
78 |
|
79 |
close(fd); |
80 |
return 0; |
81 |
} |