manage_bash_traps.sh

manage_bash_traps.sh

#!/bin/bash

# Get the commands associated with a specific signal.
function get_current_trap()
{
    local -r trap="${1-EXIT}"

    # It does not seem possible to print commands set for ERR
    if [ "${trap}" != "ERR" ]
    then
        trap -p ${trap} | sed "s/trap -- '\(.*\)' ${trap}.*/\1/"
    fi
}

# Add a command to one or more signals.
function add_to_trap()
{
    local -r add_command="${1}"
    shift
    local -r traps="${@-EXIT}"
    for trap in ${traps}
    do
        trap "$(get_current_trap ${trap})${add_command};" ${trap}
    done
}

# Remove commands from one or more signals.
function rm_from_trap()
{
    local -r remove_command="${1}"
    shift
    local -r traps="${@-EXIT}"
    for trap in ${traps}
    do
        trap "$(trap -p ${trap} | sed \
            "s/trap -- '\(.*\)' ${trap}/\1/;s/${remove_command};//")" ${trap}
    done
}


declare -r managed_traps='SIGQUIT EXIT ERR'

add_to_trap 'echo trap is printing' SIGQUIT EXIT
add_to_trap 'echo trap is still printing' SIGQUIT EXIT
add_to_trap 'echo trap is taking forever' SIGQUIT EXIT
rm_from_trap 'echo trap is printing' SIGQUIT EXIT
rm_from_trap 'echo trap is taking forever' SIGQUIT

trap -p

echo "Executing the last line of '${0}'."