Export variables and functions to use with xargs in parallel mode

xargs-example.sh

#!/usr/bin/env bash
# Bash strict mode
# Error on undefined variable: -u
# Exit on ERR: -e
# Functions inherit ERR traps: -E
# Exit on pipe failures: -o pipefail
set -eEuo pipefail

# Directory of this script
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )" 

# TRAP for exit cleanup
trap cleanup EXIT
cleanup(){
    # Put your exit cleanup code here replacing no-op character 
    :
}
# TRAP for error reporting
trap 'err_report ${LINENO}' ERR
err_report() {
    s=$?
    local LINENO=$1
    echo "$0: Error on line "$LINENO": $BASH_COMMAND"
    exit $s
}

# Write your script below

myfunction(){
    # Sleep if first parameter is "a"
    # Needed to test parallel execution
    [[ "$1" == "a" ]] && sleep 3

    echo first parameter $1
    echo all parameters $@
}

export -f myfunction
export MY_VARIABLE="foo"

export STDOUT_SAMPLE="a b c
1 2 3
x y z
foo bar baz
"

# "@@" is placeholder to be replaced
echo "$STDOUT_SAMPLE" | xargs -I@@ -P4 bash -c 'myfunction $@' -- @@