Объяснение:
9/2=4 (1); 4/2=2 (0); 2/2=1 (0); (1); 9₁₀=1001₂
34/2=17 (0); 17/2=8 (1); 8/2=4 (0); 4/2=2 (0); 2/2=1 (0); (1); 34₁₀=100010₂
59/2=29 (1); 29/2=14 (1); 14/2=7 (0); 7/2=3 (1); 3/2=1 (1); (1); 59₁₀=111011₂
629/2=314 (1); 314/2=157 (0); 157/2=78 (1); 78/2=39 (0); 39/2=19 (1); 19/2=9 (1);
9/2=4 (1); 4/2=2 (0); 2/2=1 (0); (1); 629₁₀=1001110101₂
936/2=468 (0); 468/2=234 (0); 234/2=117 (0); 117/2=58 (1); 58/2=29 (0);
29/2=14 (1); 14/2=7 (0); 7/2=3 (1); 3/2=1 (1); (1); 936₁₀=1110101000₂
1875/2=937 (1); 937/2=468 (1); 468/2=234 (0); 234/2=117 (0); 117/2=58 (1);
58/2=29 (0); 29/2=14 (1); 14/2=7 (0); 7/2=3 (1); 3/2=1 (1); (1); 1875₁₀=11101010011₂
3913/2=1956 (1); 1956/2=978 (0); 978/2=489 (0); 489/2=244 (1); 244/2=122 (0);
122/2=61 (0); 61/2=30 (1); 30/2=15 (0); 15/2=7 (1); 7/2=3 (1); 3/2=1 (1); (1);
3913₁₀=111101001001₂
11649/2=5824 (1); 5824/2=2912 (0); 2912/2=1456 (0); 1456/2=728 (0);
728/2=364 (0); 364/2=182 (0); 182/2=91 (0); 91/2=45 (1); 45/2=22 (1);
22/2=11 (0); 11/2=5 (1); 5/2=2 (1); 2/2=1 (0); (1); 11649₁₀=10110110000001₂
39578/2=19789 (0); 19789/2=9894 (1); 9894/2=4947 (0); 4947/2=2473 (1);
2473/2=1236 (1); 1236/2=618 (0); 618/2=309 (0); 309/2=154 (1); 154/2=77 (0);
77/2=38 (1); 38/2=19 (0); 19/2=9 (1); 9/2=4 (1); 4/2=2 (0); 2/2=1 (0); (1);
39578₁₀=1001101010011010₂
53746/2=26873 (0); 26873/2=13436 (1); 13436/2=6718 (0); 6718/2=3359 (0);
3359/2=1679 (1); 1679/2=839 (1); 839/2=419 (1); 419/2=209 (1); 209/2=104 (1);
104/2=52 (0); 52/2=26 (0); 26/2=13 (0); 13/2=6 (1); 6/2=3 (0); 3/2=1 (1); (1);
53746₁₀=1101000111110010₂
/* memsegments.c */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct mem
{
char text[100];
int *p;
} mem;
int cmp_by_address(const void *, const void *);
void print_struct_array(mem *, size_t);
int init_global_var = 10; /* Initialized global variable */
int global_var; /* Uninitialized global variable */
static int init_static_var = 20; /* Initialized static variable in global scope */
static int static_var; /* Uninitialized static variable in global scope */
int main(int argc, char **argv, char **envp)
static int init_static_local_var = 30; /* Initialized static local variable */
static int static_local_var; /* Uninitialized static local variable */
int init_local_var = 40; /* Initialized local variable */
int local_var; /* Uninitialized local variable */
int *dynamic_var = (int*)malloc(sizeof(int)); /* Dynamic variable */
mem structs[] =
{"Global variable (initialized)", &init_global_var},
{"Global variable (uninitialized)", &global_var},
{"Static variable (in global scope, initialized)", &init_static_var},
{"Static variable (in global scope, uninitialized)", &static_var},
{"Static variable (in local scope, initialized)", &init_static_local_var},
{"Static variable (in local scope, uninitialized)", &static_local_var },
{"Function (code)", (int*)&main },
{"Environment variable", (int*)&envp[0] },
{"Local variable (initialized)", &init_local_var },
{"Local variable (uninitialized)", &local_var },
{"Dynamic variable", dynamic_var },
};
size_t len = sizeof(structs) / sizeof(mem);
qsort(structs, len, sizeof(mem), cmp_by_address);
print_struct_array(structs, len);
free(dynamic_var);
return 0;
}
int cmp_by_address(const void *a, const void *b)
mem *ma = (mem *)a;
mem *mb = (mem *)b;
if ((unsigned)ma->p > (unsigned)mb->p)
return -1;
else if ((unsigned)ma->p < (unsigned)mb->p)
return 1;
else
/* Example struct array printing function */
void print_struct_array(mem *array, size_t len)
size_t i;
for(i=0; i<len; i++)
printf("%-50s:\t%p\n", array[i].text, array[i].p);
В результате получим:
Environment variable : 0xbff52ee0
Local variable (uninitialized) : 0xbff529ac
Local variable (initialized) : 0xbff529a8
Dynamic variable : 0x871c008
Global variable (uninitialized) : 0x804a044
Static variable (in local scope, uninitialized) : 0x804a040
Static variable (in global scope, uninitialized) : 0x804a03c
Static variable (in local scope, initialized) : 0x804a034
Static variable (in global scope, initialized) : 0x804a030
Global variable (initialized) : 0x804a02c
Function (code) : 0x80484ad
Утилита size показывает размер разделов и общий размер для объектных файлов или архивов. Так, для memsegments.o получим:
$ size memsegments.o
text data bss dec hex filename
745 12 8 765 2fd memsegments.o
Объяснение:
9/2=4 (1); 4/2=2 (0); 2/2=1 (0); (1); 9₁₀=1001₂
34/2=17 (0); 17/2=8 (1); 8/2=4 (0); 4/2=2 (0); 2/2=1 (0); (1); 34₁₀=100010₂
59/2=29 (1); 29/2=14 (1); 14/2=7 (0); 7/2=3 (1); 3/2=1 (1); (1); 59₁₀=111011₂
629/2=314 (1); 314/2=157 (0); 157/2=78 (1); 78/2=39 (0); 39/2=19 (1); 19/2=9 (1);
9/2=4 (1); 4/2=2 (0); 2/2=1 (0); (1); 629₁₀=1001110101₂
936/2=468 (0); 468/2=234 (0); 234/2=117 (0); 117/2=58 (1); 58/2=29 (0);
29/2=14 (1); 14/2=7 (0); 7/2=3 (1); 3/2=1 (1); (1); 936₁₀=1110101000₂
1875/2=937 (1); 937/2=468 (1); 468/2=234 (0); 234/2=117 (0); 117/2=58 (1);
58/2=29 (0); 29/2=14 (1); 14/2=7 (0); 7/2=3 (1); 3/2=1 (1); (1); 1875₁₀=11101010011₂
3913/2=1956 (1); 1956/2=978 (0); 978/2=489 (0); 489/2=244 (1); 244/2=122 (0);
122/2=61 (0); 61/2=30 (1); 30/2=15 (0); 15/2=7 (1); 7/2=3 (1); 3/2=1 (1); (1);
3913₁₀=111101001001₂
11649/2=5824 (1); 5824/2=2912 (0); 2912/2=1456 (0); 1456/2=728 (0);
728/2=364 (0); 364/2=182 (0); 182/2=91 (0); 91/2=45 (1); 45/2=22 (1);
22/2=11 (0); 11/2=5 (1); 5/2=2 (1); 2/2=1 (0); (1); 11649₁₀=10110110000001₂
39578/2=19789 (0); 19789/2=9894 (1); 9894/2=4947 (0); 4947/2=2473 (1);
2473/2=1236 (1); 1236/2=618 (0); 618/2=309 (0); 309/2=154 (1); 154/2=77 (0);
77/2=38 (1); 38/2=19 (0); 19/2=9 (1); 9/2=4 (1); 4/2=2 (0); 2/2=1 (0); (1);
39578₁₀=1001101010011010₂
53746/2=26873 (0); 26873/2=13436 (1); 13436/2=6718 (0); 6718/2=3359 (0);
3359/2=1679 (1); 1679/2=839 (1); 839/2=419 (1); 419/2=209 (1); 209/2=104 (1);
104/2=52 (0); 52/2=26 (0); 26/2=13 (0); 13/2=6 (1); 6/2=3 (0); 3/2=1 (1); (1);
53746₁₀=1101000111110010₂
/* memsegments.c */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct mem
{
char text[100];
int *p;
} mem;
int cmp_by_address(const void *, const void *);
void print_struct_array(mem *, size_t);
int init_global_var = 10; /* Initialized global variable */
int global_var; /* Uninitialized global variable */
static int init_static_var = 20; /* Initialized static variable in global scope */
static int static_var; /* Uninitialized static variable in global scope */
int main(int argc, char **argv, char **envp)
{
static int init_static_local_var = 30; /* Initialized static local variable */
static int static_local_var; /* Uninitialized static local variable */
int init_local_var = 40; /* Initialized local variable */
int local_var; /* Uninitialized local variable */
int *dynamic_var = (int*)malloc(sizeof(int)); /* Dynamic variable */
mem structs[] =
{
{"Global variable (initialized)", &init_global_var},
{"Global variable (uninitialized)", &global_var},
{"Static variable (in global scope, initialized)", &init_static_var},
{"Static variable (in global scope, uninitialized)", &static_var},
{"Static variable (in local scope, initialized)", &init_static_local_var},
{"Static variable (in local scope, uninitialized)", &static_local_var },
{"Function (code)", (int*)&main },
{"Environment variable", (int*)&envp[0] },
{"Local variable (initialized)", &init_local_var },
{"Local variable (uninitialized)", &local_var },
{"Dynamic variable", dynamic_var },
};
size_t len = sizeof(structs) / sizeof(mem);
qsort(structs, len, sizeof(mem), cmp_by_address);
print_struct_array(structs, len);
free(dynamic_var);
return 0;
}
int cmp_by_address(const void *a, const void *b)
{
mem *ma = (mem *)a;
mem *mb = (mem *)b;
if ((unsigned)ma->p > (unsigned)mb->p)
return -1;
else if ((unsigned)ma->p < (unsigned)mb->p)
return 1;
else
return 0;
}
/* Example struct array printing function */
void print_struct_array(mem *array, size_t len)
{
size_t i;
for(i=0; i<len; i++)
printf("%-50s:\t%p\n", array[i].text, array[i].p);
}
В результате получим:
Environment variable : 0xbff52ee0
Local variable (uninitialized) : 0xbff529ac
Local variable (initialized) : 0xbff529a8
Dynamic variable : 0x871c008
Global variable (uninitialized) : 0x804a044
Static variable (in local scope, uninitialized) : 0x804a040
Static variable (in global scope, uninitialized) : 0x804a03c
Static variable (in local scope, initialized) : 0x804a034
Static variable (in global scope, initialized) : 0x804a030
Global variable (initialized) : 0x804a02c
Function (code) : 0x80484ad
Утилита size показывает размер разделов и общий размер для объектных файлов или архивов. Так, для memsegments.o получим:
$ size memsegments.o
text data bss dec hex filename
745 12 8 765 2fd memsegments.o
Объяснение: