[Tutor] how to read one bit of a byte

[shawn bright]

even better, thanks much for this.
shawn

On 2/21/07, Kent Johnson <kent37 at tds.net> wrote:
> Luke Paireepinart wrote:
> > shawn bright wrote:
> >> lo there all,
> >>
> >> i am reading a binary file with open('myfile', 'rb')
> >>
> >> then i do a read(1) to read one byte. cool so far.
> >>
> >> but how do i read the individual bits of a byte
> >>
> >> i mean if i have a = read(1)
> >>
> >> how do i know what the msb of a is ?
> >>
> >> i need to know because i have to see if the msb is set and i also need
> >> to know the value of the next bit.
> > Well, you know the value of the MSB is...
> > 1 2 4 8 16 32 64 128
> > so if you divide the value by 128, and get a 1 and not a 0, then it's set.
> > People commonly write functions to make binary lists from values.
>
> This is also a good application of bitwise operations.
>
> a & 128 will be 128 if the high bit in a is set, 0 if it is not.
>
> Kent
>
>