Ç - 解析電話號碼從字符串

Question

我試圖從一個文件中提取電話號碼，並打印出來

輸入

my number is (123) 456-7897 ok, my other number is (654) 393-3030 buddy. 

我的變量是

char *last_token; 
char *firstpart; 
char buffer[BUFFER_SIZE]; 
char *phoneNumber; 

這裏是我當前的循環

while(fgets(buffer, BUFFER_SIZE, input) != NULL){ 
     last_token = strtok(buffer, " \n"); 
     while(last_token != NULL) { 
//see if first part of number is correct 
      if(*last_token == '(' && isdigit(*(last_token + 1)) && isdigit(*(last_token + 2)) && isdigit(*(last_token + 3)) && *(last_token + 4) == ')' && *(last_token + 5) == '\0') { 
       firstpart = last_token; //if it is save it 
       last_token = strtok(NULL, " \n"); //check next part 
//if second part is also correct 
       if (isdigit(*last_token) && isdigit(*(last_token + 1)) && isdigit(*(last_token + 2)) && *(last_token + 3) == '-' && isdigit(*(last_token + 4)) && isdigit(*(last_token + 5)) && isdigit(*(last_token + 6)) && isdigit(*(last_token + 7)) && *(last_token + 8) == '\0') { 
        phoneNumber = firstpart; //set phone number to first part 
        strcat(phoneNumber, " "); //add a space to phone number 
        strcat(phoneNumber, last_token); //add the last part of the phone nmber 

        printf("%s\n", phoneNumber); //print the number 
       } 
      } 
      last_token = strtok(NULL, " \n"); 
     } 

} 

應該打印

(123) 456-7897 
(654) 393-3030 

但代替其打印

(123) 
(654) 

即時猜測的字符串後遭到停權），但我想不出爲什麼

Answer 1

strcat(phoneNumber, " "); 

這被重寫爲'\0'到last_token的開頭。

char phoneNumber[15]; 
... 
strcpy(phoneNumber, firstpart); 
strcat(phoneNumber, " "); 
strcat(phoneNumber, last_token); 
printf("%s\n", phoneNumber);