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#!/bin/bash
name="mkbak"
version="1.0"
read -r -d '' help_message <<-EOF
Create a backup of a target file
Usage: mkbak [OPTIONS] TARGET
Options:
-d, --diff diff files before asking to overwrite
-f, --force overwrite without asking
-h, --help print this message and exit
-n FILE, --name FILE name of backup file (Default: TARGET.bak)
-q, --quiet suppress error messages and prompts
-v, --verbose show additional messages
-V, --version print version number and exit
EOF
source /usr/local/lib/mylib.bash
positional=()
quiet=0
verbose=0
force=0
backup_fn=""
while [[ $# -gt 0 ]]; do
case $1 in
-d|--diff)
debug_msg "Setting diff option to 1 (was ${diff})"
diff=1
shift
;;
-f|--force)
debug_msg "Setting force option to 1 (was ${force})"
force=1
shift
;;
-h|--help)
help_msg
shift
;;
-n|--name)
debug_msg "Setting output filename to ${2} (was ${backup_fn})"
backup_fn="$2"
shift; shift
;;
-q|--quiet)
debug_msg "Setting quiet option to 1 (was ${quiet})"
quiet=1
shift
;;
-v|--verbose)
debug_msg "Setting verbose option to 1 (was ${verbose})"
verbose=1
shift
;;
-V|--version)
version_msg
;;
*)
debug_msg "Argument '${1}' added to positional array"
positional+=("$1")
shift
;;
esac
done
# error if no filenames given
if [[ "${#positional[@]}" -lt 1 ]]; then
debug_msg "No input filename was given"
usage_msg
fi
original_fn="${positional[0]}"
# output filename
if [[ -z "$backup_fn" ]]; then
debug_msg "No output filename was given, so defaulting to 'TARGET.bak'"
backup_fn="${original_fn}.bak"
fi
# check files
if [[ ! -f "$original_fn" ]]; then
error_msg "No such file '${original_fn}'"
elif [[ "$force" -eq 0 && -f "$backup_fn" ]]; then
if /usr/bin/cmp "$backup_fn" "$original_fn" >/dev/null 2>&1; then
msg "File '${backup_fn}' already exists and is a copy of '${original_fn}'"
elif [[ $quiet -eq 0 ]]; then
if [[ "$diff" -eq 1 ]]; then
/usr/bin/diff --color "$backup_fn" "$original_fn"
fi
if ! prompt_overwrite "$backup_fn"; then
exit 1
fi
fi
fi
# main routine
/usr/bin/cp "$original_fn" "$backup_fn"
exit "$?"