Export environment variables matching a string to a file to be sourced later

setenv.sh

#!/usr/bin/env bash

# pilfered from a MSFT AKS tutorial and tweaked

if [ "$#" -ne 2 ]; then
  echo "Will export env variables that end with <search_string>"
  echo "Usage: $0 <search_string> <output_filename>"
  exit 1
fi

dir_name=$(dirname "$0")
env_search="$1"
env_export_filename="$2"
output_path="$dir_name/$env_export_filename"

if ! touch "$output_path" > /dev/null 2>&1; then
  echo "Error: Cannot write to $output_path"
  exit 1
fi

cat > $output_path << EOF
#!/usr/bin/env bash

$(env | sed -n "s/\(.*$ENV_SEARCH=\)\(.*\)/export \1'\2'/p" | sort)
EOF

cat $output_path