sprintf record a small problem

Debugging findings show imei number will flash back, tracking codes, should be suspected usage of sprintf problem, modified to solve

static void imei_abnormal(char *data) {     int nu;     int nu1;     int i=0,j=0;     memset(imei_buff,0,16);     for(i=0; i< 8 ;i++)     {         nu = data[i];         nu1 = nu;         nu1 = nu1 & 0xf;         snprintf(imei_buff+j, 16, "%x",nu1);         if (i < 7)         {             nu = nu >> 4;             snprintf(imei_buff+j+1, 16, "%x",nu);         }         j+=2;     } }

static void imei_normal(char *data) {     int nu;     int nu1;     int i=0,offset=0;     memset(imei_buff,0,16);     for(i=0;i<8;i++)     {         nu = data[i];         nu1 = nu;         nu1 = nu1 & 0xf;         offset += snprintf(imei_buff+offset, sizeof(imei_buff+offset), "%x",nu1);         if (i < 7)         {             nu = nu >> 4;             offset += snprintf(imei_buff+offset, sizeof(imei_buff+offset), "%x",nu);         }     } }