Binary data extraction

[freeurmind]

hello everybody,
i'm trying to read binary data from an input file and store their bit by bit representation in an int array for further manipulation:
- using the file.read(buffe r,1) to retrieve my first byte of data
- using unsigned char mask (for ex 0x80 = 1000 0000) i'm trying to AND it with my buffer in order to get my MSB, but i dont know how to retrieve the remaining bits. On the other hand my buffer type should it be char or unsigned char cause i repeat my data is recieved in binary from a transciever.

[amitpatel66]

hello everybody,
i'm trying to read binary data from an input file and store their bit by bit representation in an int array for further manipulation:
- using the file.read(buffe r,1) to retrieve my first byte of data
- using unsigned char mask (for ex 0x80 = 1000 0000) i'm trying to AND it with my buffer in order to get my MSB, but i dont know how to retrieve the remaining bits. On the other hand my buffer type should it be char or unsigned char cause i repeat my data is recieved in binary from a transciever.

Could you please POST your code for reference?

[freeurmind]

Could you please POST your code for reference?

Yes sure:

ifstream InputFile("Inpu t.txt",ios::in | ios::binary);
unsigned char buffer; // buffer is one byte of my data
unsigned char mask = 128; // = 1000 0000
int binarr[8]; //here is where my binary representation is stored
Bool mybit; //this should represent the bit i'm trying to retrieve
InputFile.get(b uffer);
for ( int i =0; i<8 ; i++)
{
mybit = buffer & mask;
if (mybit)
binarr[i] = 1;
else
binary[i] = 0;
buffer<<1 ; // this should be shifting my buffer 1 bit left
}


But still this aint working i'm not sure of the bitwise operators
and something weird happening cause i tried any buffer like
buffer = 157 but my binarr is getting filled with 0012FF54 and dont know where it got these numbers

[amitpatel66]

Yes sure:

ifstream InputFile("Inpu t.txt",ios::in | ios::binary);
unsigned char buffer; // buffer is one byte of my data
unsigned char mask = 128; // = 1000 0000
int binarr[8]; //here is where my binary representation is stored
Bool mybit; //this should represent the bit i'm trying to retrieve
InputFile.get(b uffer);
for ( int i =0; i<8 ; i++)
{
mybit = buffer & mask;
if (mybit)
binarr[i] = 1;
else
binary[i] = 0;
buffer<<1 ; // this should be shifting my buffer 1 bit left
}


But still this aint working i'm not sure of the bitwise operators
and something weird happening cause i tried any buffer like
buffer = 157 but my binarr is getting filled with 0012FF54 and dont know where it got these numbers

Why dont you clear your bin array and then run the code again.

[freeurmind]

Why dont you clear your bin array and then run the code again.

hey thnx for ur reply
i got it working i guess, it was very stupid, i had to use buffer <<=1 and not buffer<<1 although i'm not totally understanding the differene btw the 2 operators i guess << would just temporary shift the buffer but wouldnt change the value
anyway thnx for ur help for the time being