+ local in out=''
+ [ $# -gt 0 ] && in="$*" || in="$(cat)"
+ while [ "$in" ]; do case $in in
+ \\\\*) out="${out}\\"; in="${in#\\\\}" ;;
+ \\n*) out="${out}${BR}"; in="${in#\\n}" ;;
+ \\r*) out="${out}${CR}"; in="${in#\\r}" ;;
+ \\t*) out="${out} "; in="${in#\\t}" ;;
+ \\+*) out="${out}+"; in="${in#\\+}" ;;
+ +*) out="${out} "; in="${in#+}" ;;
+ \\*) in="${in#\\}" ;;
+ *) out="${out}${in%%[\\+]*}"; in="${in#"${in%%[\\+]*}"}" ;;
+ esac; done
+ printf '%s\n' "$out"
+}
+
+DBM() {
+ local file="$1" cmd="$2"
+ local k v key value
+ shift 2;
+
+ case "$cmd" in
+ check|contains)
+ key="$(STRING "$1")"
+ while read -r k v; do if [ "$k" = "$key" ]; then
+ return 0
+ fi; done <"$file" 2>&-
+ return 1
+ ;;
+ get)
+ key="$(STRING "$1")"
+ while read -r k v; do if [ "$k" = "$key" ]; then
+ UNSTRING "$v"
+ return 0
+ fi; done <"$file" 2>&-
+ return 1
+ ;;
+ set|store)
+ key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ { while read -r k v; do
+ [ "$k" = "$key" ] || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ printf '%s\t%s\n' "$key" "$value"
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ add|insert)
+ k="$1" key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ if DBM "$file" check "$k"; then
+ RELEASE "$file"
+ return 1
+ else
+ printf '%s\t%s\n' "$key" "$value" >>"${file}"
+ RELEASE "$file"
+ return 0
+ fi
+ ;;
+ update|replace)
+ k="$1" key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ if ! DBM "$file" check "$k"; then
+ RELEASE "$file"
+ return 1
+ fi
+ { while read -r k v; do
+ [ "$k" = "$key" ] \
+ && printf '%s\t%s\n' "$key" "$value" \
+ || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ append)
+ key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ if ! DBM "$file" check "$1"; then
+ RELEASE "$file"
+ return 1
+ fi
+ { while read -r k v; do
+ [ "$k" = "$key" ] \
+ && printf '%s\t%s\n' "$key" "$v$value" \
+ || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ delete|remove)
+ key="$(STRING "$1")"
+ LOCK "$file" || return 1
+ { while read -r k v; do
+ [ "$k" = "$key" ] || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ esac