compress-bash-script.sh

#!/bin/sh

#     name: compress-bash-script.sh
#  version: 4.1.1, 27-aug-2020, by eibgrad
#  purpose: reduce size of bash script
#    notes:
#      - trailing comments are always preserved
#      - output is always to stdout
#      - input from stdin is optional:
#          cat </path/bash-script> | compress-bash-script.sh

# --comp is the default compression level
comp=

# function usage()
usage() {
    echo 'Usage: compress-bash-script.sh [options] [</path/bash-script>]'
    echo
    echo '  Reduce size of bash script.'
    echo
    echo '  Options:'
    echo '    --nocom    remove blank lines and pure/non-functional comments'
    echo '    --comp     (default) same as --nocom, plus remove leading whitespace'
    echo '    -h,--help  this usage information'
    echo
    echo '  NOTE: If file not specifed, input is expected from stdin.'
    echo
}

# handle -h|--help option/argument
for opt; do case $opt in -h|--help) usage; exit 0;; esac; done

# process command line options/arguments
while [ $# -gt 0 ]; do
    case "$1" in
        --nocom) nocom=; unset comp;;
         --comp) comp=; unset nocom;;
              *) break 2;;
    esac
    shift
done

if [ "$1" ]; then
    if [ -f "$1" ]; then
        # redirect file to stdin
        exec "$0" $([ ${nocom+x} ] && echo --nocom) < "$1"
    else
        echo "error: file not found: $1"
        exit 1
    fi
fi

# option nocom: remove blank lines and pure/non-functional comments
[ ${nocom+x} ] && cat - | sed -r '/^[[:space:]]*($|#([[:space:]]|#|$))/d'

# option comp: same as --nocom, plus remove leading whitespace
[ ${comp+x} ] && cat - | sed -r 's/^[[:space:]]*//;/^($|#([[:space:]]|#|$))/d'

exit 0