strncat ( )【C語言庫函數原始碼】

【C語言庫函數原始碼】

【本程式在Dev C++ 4.9.9.2 下編譯通過】

/*

   Appends at most count characters of the string back onto the end of front,

and ALWAYS terminates with a null character.If count is greater than the

length of back, the length of back is used instead.(Unlike strncpy, this routine does not pad out to count characters).

   把src所指字串的前n個字元添加到dest結尾處(覆蓋dest結尾處的'/0')並添加'/0'。

   src和dest所指記憶體地區不可以重疊且dest必須有足夠的空間來容納src的字串。

   返回指向dest的指標。

*/

char * my_strncat(char *dest,const char *source,int count)

{

   char *p = dest;

   while (*p) p++;

   while (count-- && (*p++ = *source++));

   *p = '/0';

   return(dest);

}

int main()

{

   char a[20] = "ammana_";

   puts(my_strncat(a,"babi",10));

   system("pause");

   return 0;

}