Run this:
    puts "Type any characters, then <Return>."

    expect {
        ? {
            set result $expect_out(0,string)
            if {[string compare \n $result]} {
                scan $result %c value
                if {$value==27} {
                    puts "You just typed Esc (decimal ASCII 27)."
                } {
                    puts "You just typed '$result' (decimal ASCII $value)."
                }
            }
            exp_continue
        }
    }



Example output:  type "a<CR>", see decimal 97; type
"<F1><CR>", see the sequence





27-91-49-(49,50)-126
[[explain]]
Win 95










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Also see "[keysyms]", CWIND [[?]], and "[How to send escape characters through Expect]".
----
[Csan] The original code did not handle the Esc $result properly - it ate the second ' character in the output.
I added a branch to handle that case.

I also extended the output to include the octal and hexadecimal values - useful for further re-use of the $result - see further on.
Another addition was to save the resulting character (sequence) to keyseq.dat, which can be imported into another text editor.
I find this addition very useful while using 'joe' editor...

The new version of the script (I called it keyseqs.exp):

    #!/usr/bin/expect

    puts "Type any characters followed by <Return>, wait 10 seconds or press Ctrl-C."

    expect {
        ? {
            set result $expect_out(0,string)
            if [string compare \n $result] {
                if {[catch {eof $fd}]} {
                  set fd [open keyseq.dat w]
                }
                scan $result %c dvalue
                if {$dvalue==27} {
                    puts "You just typed Esc (ASCII octal  033, decimal  27, hexadecimal 1B)."
                } {
                    puts "You just typed '$result' (ASCII octal [format %4s [format %#o $dvalue]], decimal [format %3s $dvalue], hexadecimal [format %x $dvalue])."
                }
                puts -nonewline $fd $result
            } {
              if {![catch {eof $fd}]} {
                close $fd
                puts "Character (sequence) written to keyseq.dat (after flushing the file contents)."
                puts "\nType any characters followed by <Return>, wait 10 seconds or press Ctrl-C."
              }
            }
            exp_continue
        }
    }

Example output (I typed PageUp):

 # ./keyseqs.exp
 Type any characters followed by <Return>, wait 10 seconds or press Ctrl-C.
 ^[[5~
 You just typed Esc (ASCII octal  033, decimal  27, hexadecimal 1B).
 You just typed '[' (ASCII octal 0133, decimal  91, hexadecimal 5b).
 You just typed '5' (ASCII octal  065, decimal  53, hexadecimal 35).
 You just typed '~' (ASCII octal 0176, decimal 126, hexadecimal 7e).
 Character (sequence) written to keyseq.dat (after flushing the file contents).

 Type any characters followed by <Return>, wait 10 seconds or press Ctrl-C.
 #












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[LV] says:  "Believe it or not, there is no set standard for what function keys generate.
In fact, depending on the application, the same function key could generate
different values [[for different applications] on some systems."

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[Category Expect]