接受多行（）

Question

我試圖用fgets接受來自用戶的「地址」的多條線路，但我有一個Segmentation fault (core dumped)就像我離開while循環。我可以在沒有任何問題的循環中printf兩個address和part_of_address變量，而在循環它按預期工作。一旦擺脫循環，它就會着火。

// Define a char array called 'name' accepting up to 25 characters. 
char name[25]; 
// Define a char array called 'part_of_address' accepting up to 80 characters. 
char part_of_address[80]; 
// Define a char array called 'address' accepting up to 80 characters. 
char address[80]; 

// Clean the buffer, just to be safe... 
int c; 
while ((c = getchar()) != '\n' && c != EOF) {}; 

// Ask for the user to enter a name for the record using fgets and stdin, store 
// the result on the 'name' char array. 
printf("\nEnter the name of the user (RETURN when done):"); 
fgets(name, 25, stdin); 

// Ask for the user to enter multiple lines for the address of the record, capture 
// each line using fgets to 'part_of_address' 
printf("\nEnter the address of the user (DOUBLE-RETURN when done):"); 
while (1) 
{ 
    fgets(part_of_address, 80, stdin); 
    // If the user hit RETURN on a new line, stop capturing. 
    if (strlen(part_of_address) == 1) 
    { 
     // User hit RETURN 
     break; 
    } 
    // Concatinate the line 'part_of_address' to the multi line 'address' 
    strcat(address, part_of_address); 
} 

printf("This doesn't print..."); 

Answer 1

正如評論指出的邁克爾·瓦爾茲，您使用strcat(address, part_of_address);甚至在第一次，而不必初始化address。由於它是一個自動數組，它包含未定義的值，並且您正在調用未定義的行爲。很可能，即使是第strcat的address陣列後覆蓋內存。

只是char address[80] = "";或char address[80] = {'\0'};