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From: 明亮 <longapple@gmail.com>
To: linux-c-programming@vger.kernel.org
Subject: pass a local variable to a function
Date: Wed, 25 Mar 2009 08:21:48 -0800	[thread overview]
Message-ID: <56b13acf0903250921w1934942bma7280055c97a9db3@mail.gmail.com> (raw)

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?

Thanks in advance,
longapple
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             reply	other threads:[~2009-03-25 16:21 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-25 16:21 明亮 [this message]
2009-03-25 17:17 ` pass a local variable to a function Lorenzo Beretta
2009-03-26 13:09   ` Mingliang
2009-03-25 18:50 ` Bert Wesarg
2009-03-26  8:42 ` Glynn Clements
2009-03-26  9:49 ` Jon Mayo

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