Message-ID: <19971013092045.160.rocketmail@send1.rocketmail.com>
Date: Mon, 13 Oct 1997 02:20:45 -0700 (PDT)
From: Guan Foo Wah <djgpp AT rocketmail DOT com>
Subject: Is this a bug ??? or feature ??
To: djgpp AT delorie DOT com
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Check the program out below


//starts here-------------------------------------------------------
#include <stdio.h>

char *num[] = {
    "one",      //line 4
    "one",      //line 5 :- this string exactly the same as line 4
    "three",
    "four"
};

char *id[] = {
    "ten",
    "two",
    "one",      //line 13 :- exactly same as line 4 and 5
    "F16",
    "DJGPP"
};

void main (void)
{
    //prints the address of the 3 variables 
    printf ("Address : %p %p %p %p\n", num[0], num[1], id[2]);

    //prints the value of the 3 variables before modifying
    printf ("Value before modifying : %s %s %s\n", num[0], num[1],
id[2]);

    //modify one of the 3 variables
    num[0][0] = 'f';

    //prints the value of the 3 variables after modifying
    printf ("Value after modifying  : %s %s %s\n", num[0], num[1],
id[2]);
}

//ends here-----------------------------------------------------------


This is the output compiled on the DJGPP compiler (using BNU281B.ZIP)

Address : 155b 155b 155b
Value before modifying : one one one
Value after modifying  : fne fne fne



and this is the output compiled on the TURBO C v3.0

Address : 00BC 00C0 00D7
Value before modifying : one one one
Value after modifying  : fne one one



From the program output compiled on the DJGPP compiler, it seems that
num[0], num[1] and id[2] share the same location memory. Why is this
so ??
When line 4 in the code which is "one" is replaced with "one ", the
output
will change to the one below.

Address : 155f 155b 155b
Value before modifying : one  one one
Value after modifying  : fne  one one

This time, num[1], and id[2] share the same memory location.
Can anyone please tell me how to make those three variables not to
share
the same memory location ?? This is important in my project which I am
currently working on.





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