Any c programers wiling to help me with a programing issue? currently i need to read in the hex value ox1122334455667788 into an uint64_t a single byte at a time, I.E first read 0x11 then 0x22 then 0x33
Any c programers wiling to help me with a programing issue...
Isaiah Carter
Sebastian Flores
Can't you just right shift by decreasing amounts for each byte? Also, are you a cal student?
Brayden Robinson
void read(uint64_t in)
{
for (int i = 56; i >= 0; i -= 8) {
uint8_t b = (in >> i) & 0xFF;
// do things with b
}
}
Hunter Perry
>m
this wont work as im working on a 32 bit machine and the largest required right shift is larger than 32 bits
Parker Jenkins
If your machine is 32 bits then how is it holding the number in the first place? Can you split up the number and then right shift ?
Carson Williams
the number isnt actually a full number it is an array of uint8_t bytes being read 1 by 1, so my array[specified location] = 11, and at specified location + 1 it is 22 exc exc
Robert Williams
void read(uint64_t *in, uint8_t bytes[8])
{
uint8_t *p = (uint8_t *) in;
for (int i = 0; i < 8; i++) {
*(p + i) = bytes[7 - i];
}
}
something like that, for a little endian machine.
Dominic Peterson
long hex = 0x1122334455667788;
char *byte = (char*) &hex;
int i;
for (i = 0; i < sizeof(long); i++)
printf("0x%02x\n", byte[i]);
Grayson Hall
uint32_t *i = (void*)uint8array;You may have to fill in the array in reverse, depending on endianness.
Thomas Lopez
perhaps a screenshot will help clarify, im able to accsess the values individually so as you see my terminal prints 1122334455667788 one byte at a time, my issue is i ned to read the byte into ins->dest which is a uint64_t.
Austin Torres
the get_dest is the method im working in currently that is printing(1122334455667788 and 80000000, the 8000000 is a 31 point right shift, once i do a 32 point right shift the number returns to its original.
Daniel Jenkins
yes im aware i have to do it in reverse but ive taken care of that
Jordan Cook
you want the hex, e.g. 0x1234, to be interpreted as a memory address for dest? or you just want to assign a single byte to ->dest?
Cameron Long
a memory address so in otherwords ins->dest must equal 0x1122334455667788
Logan Edwards
while im reading in the bytes as 11 then 22 then 33 then 44 exc
Benjamin Russell
THE ABSOLUTE STATE OF COMPUTER """SCIENCE""" STUDENTS
Xavier Walker
you'll need a local copy of the reversed bytes. and then you'll use that to assign dest. something like:
int i, j;
long hex = 0x1122334455667788;
long rev = 0;
char *byte = (char*) &hex;
for (i = sizeof(long) - 1, j = 0; i >= 0; i--, j++)
memcpy(((char*)&rev) + j, byte + i, 1);
printf("0x%08lx\n", rev);
Matthew Robinson
kek
Austin Rogers
you could also just put each byte into `dest' as I did for `rev'.
Alexander Moore
uint64_t number:
for(int i = 7; i >= 0; i--) {
*((char*)number + i) = read_char();
}
Grayson Rivera
Here's how to do it in assembly sort of :^)
MOV ESI, OFFSET a_hex
DEC ESI
MOV EBX, 0
MOV EDX, 0
MOV EAX, OFFSET hex_count
MOV ECX, [EAX]
CMP ECX, 1
JZ One_Char
INC ECX
PUSHAD
L_O:
POPAD
INC ESI
DEC ECX
MOV EDI, OFFSET valid_hex ;valid_hex = array of all valid hex characters
MOV DL, [ESI]
PUSHAD
MOV EAX, 0
MOV AL, stop_condition
CMP AL, DL
JZ Valid_Array
CMP ECX, 0
JZ Invalid_Array
MOV ECX, 0
MOV CL, valid_hex_size
L1:
MOV BL, [EDI]
CMP DL, BL
JZ L_O
ADD EDI, 1
DEC CL
CMP CL, 0
JNZ L1
JMP Invalid_Array
Valid_Array:
POPAD
CALL crlf
MOV EDX, OFFSET s_valid
CALL writestring
CALL crlf
RET
Invalid_Array:
POPAD
CALL crlf
MOV EDX, OFFSET s_invalid
CALL writestring
CALL crlf
RET
One_Char:
CALL crlf
MOV EDX, OFFSET s_invalid
CALL writestring
CALL crlf
RET
Mason Ward