.functions

# print currently active shell
shell () {
  ps -p $$ | tail -1 | awk '{print $NF}'
}

mcd () {
    mkdir -p $@ && cd $1 && echo "Created directory \"$@\""
}

# calculate difference between two dates in days, hours and minutes
# order of parameters doesn't matter
datediff() {
    if [ $# -lt 1 ]; then
        echo "Computes a difference between the starting and ending date and time in days, hours and minutes."
        echo "If the second argument is omitted, the current date and time is used as the ending date.\n"
        echo "Usage: datediff <start> [end]\n"
        echo 'datediff <hh>[:mm][:ss] <hh>[:mm][:ss]'
        echo 'datediff "<YYYY-MM-DD> [hh][:mm][:ss]" "<YYYY-MM-DD> [hh][:mm][:ss]"'
        return
    fi

    # use the current date and time if second argument is omitted
    if [ $# -lt 2 ]; then
        2=`date`
    fi

    # check if arguments are valid dates
    d1=$(date -d "$1")
    if  [ $? -ne 0 ]; then
        echo 'First argument is not a valid date'
        return
    fi
    d2=$(date -d "$2")
    if  [ $? -ne 0 ]; then
        echo 'Second argument is not a valid date'
        return
    fi

    # display parsed and normalized dates
    echo "Start: $d1"
    echo "End:   $d2"
    echo

    # convert input dates to unix timestamps
    d1=$(date -d "$1" +%s)
    d2=$(date -d "$2" +%s)

    # calculate a difference in seconds
    diff=$(( (d1 - d2) > 0 ? (d1 - d2) : (d2 - d1) ))

    # format and print the difference
    days=$(( diff / 86400 ))
    hours=$(( (diff % 86400) / 3600 ))
    hours_total=$(( diff / 3600 ))
    minutes=$(( ((diff % 86400) % 3600) / 60 ))
    seconds=$(( ((diff % 86400) % 3600) % 60 ))

    echo "Difference:  $days day(s) $hours hour(s) $minutes minute(s) $seconds seconds(s)"
    echo "             $hours_total hour(s) $minutes minute(s) $seconds seconds(s)"
    echo "             $diff second(s)"
}

# find <paramater> in stdin, highlight it and send it to stdout
highlight () {
    # perl -pe "s/$1/\e[1;31;43m$&\e[0m/g"
    perl -pe "s/$1/$fg[black]$bg[green]$&\e[0m/g"
}