Expect - special characters without escape

expect_argv

#!/usr/bin/expect -f
#############################################################################
#
# Arguments passed on the command line end up as a list of escaped strings.
# Hence you can eval them to get the literal values properly entered into
# an expect command.
#
#   ./expect_argv '---&;`'\''"|*?~<>^()[]{}$\---'
#   ---&;`'"|*?~<>^()[]{}$\---
#

eval spawn -noecho printf "%s\\n" $argv
expect eof

expect_env

#!/usr/bin/expect -f
#############################################################################
# Variables have values that have already been stored with expect (and hence
# do not need escaping).  If you set the variable in the script yourself then
# obviously you need to tcl escaping, but if you inherit variables from the
# environment then the values will already be entered.
#
#   export VAR='---&;`'\''"|*?~<>^()[]{}$\---'
#   ./expect_env
#   ---&;`'"|*?~<>^()[]{}$\---
#

puts $env(VAR)

expect_file

#!/usr/bin/expect -f
#############################################################################
# As with the `expect_env` example, the strategy is to get the strings into
# variables thereby avoid having to escape special characters.  Rather than
# using ENV, this uses a file to provide the values.
#
#   printf "%s\n" '---&;`'\''"|*?~<>^()[]{}$\---' > file
#   ./expect_file
#   ---&;`'"|*?~<>^()[]{}$\---
#

set input [open "file" "r"]
gets $input line
puts $line