interaction.exp

#!/usr/bin/env expect

# DOCUMENTATIONS: https://www.mkssoftware.com/docs/man1/expect.1.asp
#                 https://stackoverflow.com/questions/43198502/error-handling-in-tcl

# TCL expect

if { [llength $argv] != 2 } {
    puts "expect interaction.exp <executable> <test-commands>"
    exit 1
}

set executable [lindex $argv 0]
set arg1 [lindex $argv 1]
set TEST [string trim $arg1]
set test_cmds [split $TEST "\n"]

# add safety-last-element due to 'string trim' cmd
#lappend test_cmds "safety-trailer" 

spawn $executable

set timeout 0
set test_cmd_counter 0

foreach test_cmd $test_cmds {

    incr test_cmd_counter

    expect "."
    if { [ catch {send "$test_cmd\r"} caught_msg ] } {
        puts "RUNTIME ERROR OCCURRED: your program terminated before command $test_cmd_counter: '$test_cmd'"
        puts "-> $caught_msg"
        break
    }
    sleep 0.1
    expect *    
}
# expect * : clear input buffer




#expect eof