將結構成員複製到陣列

Question

struct { 
    char a[10]; 
    char b[5]; 
    char c[10]; 
} info; 

如何將所有的struct數據成員連接成一個數組成員？

Answer 1

隨着memcpy()：

// Assign a buffer big enough to hold everything 
char *buf = malloc(sizeof(info.a) + sizeof(info.b) + sizeof(info.c)); 
// Get a pointer to the beginning of the buffer 
char *p = buf; 
// Copy sizeof(info.a) bytes of stuff from info.a to p 
memcpy(p, info.a, sizeof(info.a)); 
// Advance p to point immediately after the copy of info.a 
p += sizeof(info.a); 
// And so on... 
memcpy(p, info.b, sizeof(info.b)); 
p += sizeof(info.b); 
memcpy(p, info.c, sizeof(info.c)); 

Answer 2

你可以用sprintf。這funcions「打印」字符串轉換成anoter：

int struct_size = sizeof(info); 
char *result = (char*)malloc(sizeof(char)*struct_size); 
sprintf(result, "%s%s%s", info.a, info.b, info.c);