rrb_interval

#!/bin/sh

# Run rrb if it was last run more than the specified number of seconds ago.
# Useful in cron-scripts for clients, that are not online all the time.

set -e
HELP="Usage: $0 interval config"
EX_USAGE=64
EX_CONFIG=78
unset DEST_DIR

fail()
{
  echo -e "$1" >&2
  exit $2
}
do_rrb()
{
    exec rrb $CONFIG
}

INTERVAL="$1"
CONFIG="$2"
[ "$#" -eq 2 ]        || fail "Invalid usage.\n$HELP" $EX_USAGE
[ "$INTERVAL" ]       || fail "Interval missing.\n$HELP" $EX_USAGE
[ "$INTERVAL" -ge 1 ] || fail "Invalid interval.\n$HELP" $EX_USAGE
[ "$CONFIG" ]         || fail "Config file missing.\n$HELP" $EX_USAGE
source $CONFIG
[ "$DEST_DIR" ]       || fail "Invalid config file, missing \$DEST_DIR.
$HELP" $EX_CONFIG

LATEST_DIR="$DEST_DIR/latest"
[ -e "$LATEST_DIR" ] || do_rrb
# date does not parse datetime with 'T' as delimiter correctly, replace with
# space. (Or it does it correctly by recognizing the timezone, but this is not
# wanted here)
DATE_LAST=`date --date="\`readlink $LATEST_DIR | tr T ' '\`" +%s`
DATE_LIMIT=`echo "\`date +%s\` - $INTERVAL" | bc`
[ $DATE_LAST -le $DATE_LIMIT ] && do_rrb