Making strings into numbers

[tomdagliusa]

If I parse the expect_out buffer and extract a string, how do I then convert that string into a number?

My goal is to extract the string: ex. 01234567
Then convert the string into hex: ex. 0x01234567
Then do ands or or's with the hex value:
set hi_word_mask "FFFF0000"
set hi_word_value [expr $hi_word_mask & $hex_value]

Now that I type the question, I can think of another.
How do I make my variable "hi_word_mask" a number,
and not a string?

Thanks,
Tom

 

[ulis]

Tcl knows only strings, lists and arrays, defaulting to strings.

When you write: set x 123, this means: set x "123".

But expr knows about numbers; decimal, octal AND hexadecimal numbers.
For hexadecimal numbers simply prepend 0x to the numeral string before using expr (more in the expr page).

set x1 0x1234
set x2 0x1111
set or [expr {$x1 | $x2}]
puts [format "0x%x" $or]

And you should get : 0x1335

ulis

 

[tomdagliusa]

Ulis,

Thanks. I played around with variations of what you
wrote before typing my question, but your example
helped greatly.

Tom