BASH functions to read values of set -e, -x, etc and be able to save them, and restore them later, eg. at the end of a function that wants to handle its errors.

shell-set.sh

#!/usr/bin/env bash
# ———————————————————————————————————————————————————————
# BashMatic Utilities Library
# ———————————————————————————————————————————————————————
# © 2017-2020 Konstantin Gredeskoul, All rights reserved.
#
# Distributed under the MIT LICENSE.
#
# Sources: https://github.com/kigster/bashmatic
# ———————————————————————————————————————————————————————
# 
# This part of the library deals with Shell's set properties.
# As you may know you can call set -e/+e or set -x/+x and so on
# to control various behaviors of the shell.
# 
# Sometimes when we run a subroutine, we want to not fail on 
# error, and set +e is the solution. However, what if before we 
# entered the subroutine, that option was set to -e instead?
# In this case the right thing to do is to restore it to whatever
# it was prior to changing it. 
#
# This is what this library is about. It maintains a stack
# of set values for each call to shell-set::push-stack "character"
# and subsequently restore with shell-set::pop-stack "character".
# It works with both +{value} and -{value} — whatever the state is
# it is pushed on top of the stack.
#
# Example:
#
#    #!/usr/bin/env bash
#    source ~/.bashmatic/lib/shell-set.sh
#    # we set this because we want to fail on errors
#    set -e
#
#    # this function has a body that might trigger a failure
#    # but we'd rather handle it in the function than abort.
#    function myfunc() {
#       shell-set::push-stack e             # save the state of set -e/+e
#
#       set +e
#       # perform operation that may fail
#
#       shell-set::pop-stack e              # now set -e/+e is restored.
#    }
#
#

shell-set::is-set() {
  local v="$1"
  local is_set=${-//[^${v}]/}
  if [[ -n ${is_set} ]] ; then
    return 0
  else
    return 1
  fi
}

shell-set::show-stack() {
  info "Current Shell Set Stack: ${bldylw}[${SetOptsStack[*]}]"
}

shell-set::init-stack() {
  unset SetOptsStack
  declare -a SetOptsStack=()
  export SetOptsStack
}

shell-set::push-stack() {
  local value="$1"
  local is_set=${-//[^${value}]/}

  shell-set::is-set ${value} && export SetOptsStack=(${SetOptsStack[@]} "-${value}")
  shell-set::is-set ${value} || export SetOptsStack=(${SetOptsStack[@]} "+${value}")

  [[ -n ${DEBUG} ]] && shell-set-show
}

shell-set::pop-stack() {
  local value="$1"
  
  local len=${#SetOptsStack[@]}
  local last_index=$(( len - 1 ))
  local last=${SetOptsStack[${last_index}]}
  if [[ ${last} != "-${value}" && ${last} != "+${value}" ]]; then
    error "Can not restore ${value}, not the last element in ${SetOptsStack[*]} stack."
    return 1
  fi

  local pop=(${last})  

  export SetOptsStack=("${SetOptsStack[@]/$pop}")
  [[ -n ${DEBUG} ]] && shell-set-show
  eval "set ${last}"
}

# Deprecated
save-set-x()     { shell-set::push-stack x; }
save-restore-x() { shell-set::pop-stack x ; }

[[ -z "${SetOptsStack[*]}" ]] && shell-set::init-stack