On Wed, Mar 25, 2009 at 17:21, 明亮 <longapple@xxxxxxxxx> wrote:> Hi guys,>> This is my first email in this list, any help is much appreciated.> As I know, it's not allowed to pass a local variable to a function,> because the stack where local variable resides will be reused by other> functions.> eg:> 1 #include <stdio.h>> 2> 3 char *fetch();> 4> 5 int main(int argc, char *argv[]){> 6 char *string;> 7 string = fetch();> 8 printf("%s\n", string);> 9 exit(0);> 10 }> 11> 12 char *fetch(){> 13 char string[10];> 14 scanf("%s", string);> 15 return string;> 16 }>> When the application is executed, after input "a", it will produce> unknown characters, like "8Šè¿ôÿO". Which is like what I expect>> However, if I change line 13 to:> 13 char string[1024];>> When I type "a", it echos "a", which is out of my expectation>> Why does it behave like this?That is irrelevant. What you try to do is 'undefined behavior', so youshould have no expectations, whether it works for you or not.
Bert>> Thanks in advance,> longapple��.n��������+%������w��{.n�����{��ji���^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�m
