How To Determine If Variable Is a Binary String 1

[bgong]

Does anyone know how to determine if a variable that is passed in as an argument in a procedure is a binary string? The [string is .. ] command does not seem to cover this data type.

 

[Bong]

Do you mean "does the input string contain only 1's and 0's"?
If that's what you mean, regexp is probably what you want:
regexp {^[0-1]} <your string>

_________________
Bob Rashkin

 

[bgong]

No, I'm referring to a binary string that's created with the 'binary format' command, which creates an array of binary data.

 

[Bong]

Then you can use the binary scan function and catch the return. If it's 0, you're good.

_________________
Bob Rashkin

 

[Bong]

Maybe it's 1 that means you're good, as a return from catch. I guess it depends on what you want to see.

_________________
Bob Rashkin

 

[bgong]

It doesn't look like 'binary scan' will do the trick, as the
following example shows that binary scan will return 1
whether the variable is a binary string or a list of integers.

% binary scan [binary format c* {0 1 2}] c* a
1
% set a
0 1 2
% binary scan {0 1 2} c* a
1
% set a
48 32 49 32 50

But you've given me an idea. All I really want to do is
differentiate between a binary string and a list of integers,
so I can catch the return on format %d:

% format %d [lindex {0 1 2} 0]
0
%format %d [lindex [binary format c* {0 1 2}] 0]
expected integer but got "??"

Thanks for the input.