disco/universe/bin/disco-param

#!/bin/bash

PARAMROOT=/var/disco/parameters

function check_names_regex() {
    echo $1 | grep -E '^[a-zA-Z0-9_\-\.\/]*$' >/dev/null 2>&1
    if [ $? -ne 0 ]; then
	echo "error: Invalid characters in pathname '$1'. Valid pathname characters are [a-zA-Z0-9_-.\/]*." >&2
	exit 1
    fi
    echo "$1" | grep "^/" >/dev/null 2>&1
    if [ $? -eq 0 ]; then
	echo "error: Pathnames cannot start with /" >&2
	exit 1
    fi
}

function disco_delete() {
    if [ "$1" == "--help" ] || [ "$1" == "" ]; then
	echo "info: disco-param delete [PATH_NAME] [optarg]... deletes parameter trees (recursively, if optarg is '-r'). PATH_NAME must not be empty." >&2
	exit 1
    fi
    check_names_regex "$1" || exit 1
    cd ${PARAMROOT}
    if [ "$2" == "-r" ]; then
        OUT=$(rm -rf ${1} 2>&1)
    elif [ -d ${PARAMROOT}/${1} ]; then
	# We want the error message from rmdir to have just the key path, not the param root in it
	OUT=$(rmdir ${1} 2>&1)
    else
	OUT=$(rm -f ${1} 2>&1)
    fi
    if [ "$OUT" != "" ]; then
	echo "error: $OUT" >&2
	exit 1
    fi
    exit 0
}

function disco_set() {
    if [ "$1" == "--help" ]; then
	echo "info: disco-param set [PATH_NAME] [optarg] ... reads from stdin and sets PATH_NAME, unless [optarg] is {}, in which case a new hierarchy is made" >&2
	echo "info: disco-param set - .... Reads lines from stdin, with each line being PATH_NAME=VALUE, and performs 'set' for each pair." >&2
	exit 1
    fi

    if [ "$1" == "-" ]; then
	RETVAL=0
	while read LINE
	do
	    PATHNAME=$(echo $LINE | cut -d = -f 1)
	    VALUE=$(echo $LINE | cut -d = -f 2-| sed s/"^\s*"//g)
	    echo $PATHNAME = $VALUE
	    if [ "$VALUE" == "{}" ]; then
		disco_set $PATHNAME "{}"
	    else
		echo $VALUE | disco_set $PATHNAME
	    fi
	    RETVAL=$(expr $RETVAL + $?)
	done
	exit $RETVAL
    fi

    check_names_regex "$1" || exit 1
    mkdir -p $(dirname ${PARAMROOT}/${1})
    if [ "$2" == "" ]; then
	cat > ${PARAMROOT}/${1}
    elif [ "$2" == "{}" ]; then
	if [ -e ${PARAMROOT}/${1} ] && [ ! -d ${PARAMROOT}/${1} ]; then
	    echo "error: ${1} : existing type '$(stat -c '%F' ${PARAMROOT}/${1})' cannot be overriden with type 'directory'." >&2
	    exit 1
	fi
	mkdir -p ${PARAMROOT}/${1}
    else
	echo "error: Unknown optarg '$2'." >&2
	exit 1
    fi
}

function disco_keys() {
    if [ "$1" == "--help" ]; then
	echo "info: disco-param keys [PATH_NAME] ... returns a list of all keys present in the toplevel of the given directory" >&2
	exit 1
    fi
    VARPATH=$(echo $1 | sed s/"^\/*"//g)
    check_names_regex "$VARPATH" || exit 1
    if [ -d ${PARAMROOT}/${VARPATH} ]; then
	# Iterate over the path like a key/value dictionary
	cd ${PARAMROOT}/${VARPATH}
	for file in $(ls 2>/dev/null);
	do
	    echo $file
	done
	exit 0
    else
	echo "error: $VARPATH does not exist or is not a directory" >&2
	exit 1
    fi
}

function disco_dump() {
    if [ "$1" == "--help" ]; then
	echo "info: disco-param dump [PATH_NAME] ... Print each key/value pair in the tree in PATH_NAME = VALUE format, one per line." >&2
	exit 1
    fi
    VARPATH=$(echo $1 | sed s/"^\/*"//g)
    check_names_regex "$VARPATH" || exit 1
    cd $PARAMROOT
    find $VARPATH | sed s/"^\.\/*"//g | grep -v "^$" | while read line; do if [ -d $line ]; then echo $line = '{}' ; else echo $line = $(cat $line); fi; done | sort -u
    exit 0
}

function disco_get() {
    if [ "$1" == "--help" ]; then
	echo "info: disco-param get [PATH_NAME] ... Get the value of the given path name." >&2
	exit 1
    fi
    VARPATH=$(echo $1 | sed s/"^\/*"//g)
    check_names_regex "$VARPATH" || exit 1
    cd $PARAMROOT
    if [ -d ${PARAMROOT}/${VARPATH} ]; then
	echo '{}'
    else
	cat ${PARAMROOT}/${VARPATH}
    fi
    exit $?
}

if [ "$1" == "--help" ]; then
    echo "info: disco-param [CMD] [OPTIONS] ... execute the given command with the given options, and return zero on success."
    echo
    $0 set --help
    $0 get --help
    $0 dump --help
    $0 delete --help
    $0 keys --help
    exit 0
fi

disco_$1 "$2" "$3" "$4" "$5" "$6"
exit $?
#  LocalWords:  regex