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2008-11-03T05:18:50Z

10 revision(s)

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The lab task for todays lab was to find more and explore pointers and different data structures.
I have done a number of different tasks and compiled and ran these on 2 different machines, on a windows
operating system (x32) and on a LINUX machine (x64) to see what effect that would have on my results.

=== task1 ===
for task 1 .. my code was :
<pre>
char *ip;
double *ip1;
short *ip2;
float *ip3;
long *ip4;
printf("ip = %d\nip1 = %d\nip2 = %d\nip3 = %d\nip4 = %d\n",
sizeof(ip),sizeof(ip1),sizeof(ip2),sizeof(ip3),sizeof(ip4));
</pre>

and the output on the vista os was:
<pre>
ip = 4
ip1 = 4
ip2 = 4
ip3 = 4
ip4 = 4
</pre>

while the output on the linux machine was:
<pre>
ip = 4
ip1 = 4
ip2 = 4
ip3 = 4
ip4 = 4

</pre>

=== task2 ===
a)
<pre>
printf("address of x= %p, address of y= %p, difference= %ld\n",&x, &y ,(long)(&x - &y));
</pre>

output on windows:
<pre>
address of x= 0x22ccc4, address of y= 0x22ccc0, difference= 1
</pre>

ouput on linux:
<pre>
&x = 0xfff0b9dc, &y = 0xfff0b9d8, diff = 1
</pre>

i was asked to do a little editing to the code:
<pre>
printf("address of x= %p, address of y= %p, difference= %ld\n",&x, &y ,((long)&x -(long)&y));
</pre>

output on windows:
<pre>
address of x= 0x22ccc4, address of y= 0x22ccc0, difference= 4
</pre>

output on LINUX:
<pre>
&x = 0xfff0b9dc, &y = 0xfff0b9d8, diff = 4
</pre>

=== task3 ===
<pre>
printf("sizeof arr = %d\n", sizeof(arr));
</pre>

output on windows:
<pre>
sizeof arr = 4
</pre>

output on LINUX:
<pre>
size of arr = 4
</pre>

c)
<pre>
printf("address of arr = %p",&arr);
</pre>

output on WINDOWS:
<pre>
address of arr = 2280640
</pre>

output on LINUX:
<pre>
address of arr = 0xffc1d9d4
</pre>

d)
<pre>
printf("arr+4 = %d, &arr[4]= %d", arr+4,&arr[4]);
</pre>

output on LINUX:
<pre>
arr+4 = -2225704, &arr[4]= -2225704
</pre>

e)
<pre>
for (i =0; i < 10; i++){
arr[i];
printf("diff &x - &y = %d\n",(long)(&x - &y));
</pre>

output on WINDOWS:
<pre>
diff btwn &x and &y whn arr[0] = 8
diff btwn &x and &y whn arr[1] = 2
diff btwn &x and &y whn arr[2] = 2
diff btwn &x and &y whn arr[3] = 8
diff btwn &x and &y whn arr[4] = 2
diff btwn &x and &y whn arr[5] = 8
diff btwn &x and &y whn arr[6] = 8
diff btwn &x and &y whn arr[7] = 8
diff btwn &x and &y whn arr[8] = 4
diff btwn &x and &y whn arr[9] = 8
diff btwn &x and &y whn arr[10] = 8

</pre>

output on LINUX:
<pre>
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
diff &x - &y = 1
</pre>

f)
<pre>
printf("x = %d, y = %d",x,y);
</pre>

output on WINDOWS:
<pre>
x = 10, y = 0
</pre>

output on LINUX:
<pre>
x = 167772160, y = 0
</pre>

=== task4 ===

<pre>
X and y as global variables
printf("&x = %p, &y = %p, diff = %ld\n",&x,&y, (long)(&x - &y));
printf("&x = %p, &y = %p, diff = %ld\n",&x,&y, (long)&x - (long)&y);
printf(“sizeof(arr) = &d”, sizeof(arr));
printf("address of arr = %d",&arr);
printf("address of arr+4 = %d",&arr+4);
printf("address of arr [4]= %d",&arr[4]);
</pre>

output on WINDOWS:
<pre>
&x = 0x403030, &y = 0x403020, diff = 4
&x = 0x403030, &y = 0x403020, diff = 16
sizeof(arr) = 4
address of arr = 4206640
address of arr+4 = 4206656
address of arr[4] = 4206644
</pre>
<pre>
diff btwn &x and &y whn arr[0] = 8
btwn &x and &y whn arr[1] = 8
diff btwn &x and &y whn arr[2] = 8
diff btwn &x and &y whn arr[3] = 8
diff btwn &x and &y whn arr[4] = 8
diff btwn &x and &y whn arr[5] = 8
diff btwn &x and &y whn arr[6] = 8
diff btwn &x and &y whn arr[7] = 8
diff btwn &x and &y whn arr[8] = 8
diff btwn &x and &y whn arr[9] = 8
diff btwn &x and &y whn arr[10] = 8

</pre>

=== task5 ===
<pre>
int *p1, *p2;
{ int q; p1 = &q; }
{ int r; p2 = &r; }
</pre>

output on WINDOWS:
<pre>
p1 = 2280636 , p2 = 2280632
</pre>

output on LINUX:
<pre>
p1 = -7644716, p2 = -7644716
</pre>

=== task6 ===
<pre>
sp = local str( );
printf( ”sp = %p(%s)\n”, sp, sp );
sp = local str( );
local str2( );
printf( ”sp = %p(%s)\n”, sp, sp );
sp = static str( );
local str2( );
printf( ”sp = %p(%s)\n”, sp, sp );
sp = malloc str( );
local str2( );
printf( ”sp = %p(%s)\n”, sp, sp );
</pre>

output on WINDOWS:
<pre>
sp = 0x22cc90(456)
sp = 0x22cc90(efg)
sp = 0x402000(tuvwxyz)
sp = 0x10401a0(hijklmn)
</pre>

output on LINUX:
<pre>
sp = 0xffbc29a4(þîÐ)
sp = 0xffbc29a4(abcdefg)
sp = 0x10010cd4(tuvwxyz)
sp = 0x10011008(hijklmn)
</pre>

<pre>
strcpy( sp, ”XXXXXXX” );
printf( ”sp X’d = %p(%s)\n”, sp, sp );
</pre>

output on WINDOWS:
<pre>
sp = 0x22cc90(456)
sp X'd = 0x22cc90(-0@)
sp = 0x22cc90(efg)
sp X'd = 0x22cc90(-0@)
sp = 0x402000(tuvwxyz)
sp X'd = 0x402000(XXXXXXX)
sp = 0xda01a0(hijklmn)
sp X'd = 0xda01a0(XXXXXXX)
</pre>

output on LINUX:
<pre>
sp = 0xffb0f9a4(þîÐ)
sp X'd = 0xffb0f9a4(XXXXXXX)
sp = 0xffb0f9a4(abcdefg)
sp X'd = 0xffb0f9a4(XXXXXXX)
sp = 0x10010dc0(tuvwxyz)
sp X'd = 0x10010dc0(XXXXXXX)
sp = 0x10011008(hijklmn)
sp X'd = 0x10011008(XXXXXXX)
</pre>

=== task7 ===
output on WINDOWS:
<pre>
&my_struct = 0x0
offsets:
my_char: 0
my_short: -2
my_int: -4
my_long: -8
my_float: -12
my_double: -16
</pre>

output on LINUX:
<pre>
&my_struct = 0xffe879c0
offsets:
my_char: 0
my_short: -2
my_int: -4
my_long: -8
my_float: -12
my_double: -16
</pre>

=== task8 ===
output on WINDOWS:
<pre>
&my_struct = 0x0
offsets:
my_char: 0
my_short: 0
my_int: 0
my_long: 0
my_float: 0
my_double: 0
</pre>

ouput on LINUX:
<pre>
&my_struct = 0xffafe9d8
offsets:
my_char: 0
my_short: 0
my_int: 0
my_long: 0
my_float: 0
my_double: 0
</pre>

=== task9 ===
output on WINDOWS:
<pre>
sp1 address: 0x22ccc4
sp2 address: 0x22ccc0
sp3 address: 0x22ccbc
</pre>

output on LINUX:
<pre>
sp1 address: 0xffb5b9dc
sp2 address: 0xffb5b9d8
sp3 address: 0xffb5b9d4
</pre>

=== task10 ===

output on windows:
<pre>
local_str = 0x401050
</pre>

ouput on LINUX:
<pre>
local_str = 0x100004dc
</pre>

SE250:lab-2:aomr001 - Revision history

Mark: 10 revision(s)