Question

I write regex in Expect script and want use ([0-9]+)\r as regex pattern. To prevent of […] substitution I use curved braces:

expect -re {([0-9]+)\r} {...}

But \r in {…} have no special meaning in braces (treated as two chars). I try

expect -re {([0-9]+)}\r {...}

But this take parsing error. I try

expect -re [concat {([0-9]+)} "\r"] {...}

But concat add space between args.

PS. I know another solution with “…” quotes by quoting [:

expect -re "(\[0-9]+)\r" {...}

but would like hear solution with {…} quoting style…

Answer 1

You are correct: \r has no meaning inside { }, for that you need to use double quote, but need to escape the square brackets:

expect -re "(\[0-9\]+)\r" ...

If you want to concatenate:

set expression {([0-9]+)}
append expression "\r"
expect -r $expression