Read RFID data

Read RFID data... 因為只需要數字 0~9，所以 map 只寫到 0~9 (感謝solar協助)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <linux/input.h>

#define DEBUG_ENV

#ifdef DEBUG_ENV
#define DEBUGF(fmt,args...) printf(fmt ,##args)
#else
#define DEBUGF(fmt,args...)
#endif


#define KEYWD "Sycreader RFID Technology"

typedef struct _EvcMap
{
    char code;
    char chr;
} _EvcMap_t;

_EvcMap_t _map_[] =
{
    {KEY_1, '1'},
    {KEY_2, '2'},
    {KEY_3, '3'},
    {KEY_4, '4'},
    {KEY_5, '5'},
    {KEY_6, '6'},
    {KEY_7, '7'},
    {KEY_8, '8'},
    {KEY_9, '9'},
    {KEY_0, '0'},
};

char evc_map(struct input_event* ev)
{
    int i;
    for(i = 0; i < sizeof(_map_) / sizeof(_EvcMap_t); i++)
    {
        if(_map_[i].code == ev->code)
        {
            return _map_[i].chr;
        }
    }
    DEBUGF("No map:%d!\n", ev->code);
    return 0;
}


int ReadRFID (char *target, int time_sec, char* read_code)
{
    struct timeval Timeout;
    struct input_event t;
    char time_flag=0;
    fd_set readfs;
    char path[256];
    int keys_fd;
    char ret[2];
    int rv=0;
    char getnum[16];
    int i=0;

    *read_code = 0;

    if (time_sec > 0 && time_sec < 1200)
        time_flag=1;
    if (time_sec > 1200)
    {
        DEBUGF("set time to long\n");
        return -1;
    }
    if (time_sec == 0)
        time_flag=0;


    sprintf(path, "/dev/input/%s", target);
    DEBUGF("path=[%s]\n", path);

    keys_fd = open (path, O_RDONLY);
    if (keys_fd <= 0)
    {
        DEBUGF ("open %s device error!\n", path);
        return -1;
    }

    /* set timeout value within input loop */
    Timeout.tv_usec = 0;  /* milliseconds */
    Timeout.tv_sec  = time_sec;  /* seconds */

    for(;;)
    {
        if(time_flag)
        {
            rv = select(keys_fd+1, &readfs, NULL, NULL, &Timeout);
            if (rv==0)
            {
                DEBUGF("timeout!!\n");
                return -1;
            }
        }

        if(read(keys_fd, &t, sizeof (t)) == sizeof (t))
        {
            if (t.type == EV_KEY && t.value == 0)
            {
                if((*read_code = evc_map(&t)))
                    read_code++;
                else
                    break;
            }
        }
    }

    close (keys_fd);
    return 0;
}


int FindPath (char **target)
{
    char str[512];
    char kwd[128];
    char *pwd=NULL;
    char flag=0;
    FILE *fp = fopen ("/proc/bus/input/devices", "r");
    int i=0, j=0;
    if (fp==NULL)
    {
        DEBUGF("Open Error!Check if the file is exist and you have the permission!\n");
        return -1;
    }

    while(!feof(fp))
        if(fgets(str,128,fp)!=NULL)
        {
            pwd=strstr(str, KEYWD);
            if (pwd)
            {
                DEBUGF("1-%s", pwd);
                flag=1;
                break;
            }
        }

    if(flag)
    {
        //target at 4th row
        fgets(str,128,fp);
        fgets(str,128,fp);
        fgets(str,128,fp);
        fgets(str,128,fp);
        DEBUGF("2-%s\n", str);
        pwd=strstr(str, "event");
        DEBUGF("3-[%s]\n", pwd);
        strcpy(*target, pwd);
        pwd=*target;
        for(;;)
        {
            if(*pwd!=0)
                switch(*pwd)
                {
                case 0x20:
                case '\r':
                case '\n':
                    *pwd=0;
                    break;
                default:
                    *(*target+i)= *pwd;
                    pwd++;
                    i++;
                    break;
                }
            else
                break;
        }
        return 0;
    }
    else
    {
        target = NULL;
        return -1;
    }

    fclose(fp);
}


int main ()
{
    char *target;
    char read_code[32];
    int i=0;

    target=malloc(sizeof(char)*8);

    i = FindPath(&target);
    if (i < 0)
    {
        DEBUGF("Can't find the RFID devices\n");
        return -1;
    }

    DEBUGF("target=[%s]\n", target);

    ReadRFID(target, 0, read_code);

    printf("RFID:%s\n", read_code);

    free(target);
    return 0;
}