#!/bin/bash

NAME_REGEX=".*"
LINE_L=1
LINE_R=-1
DIR="."

ER () {
    echo $1
    exit 1
}

while [[ $# > 0 ]]; do
    arg=$1
    shift
    case $arg in
        -name)
            NAME_REGEX=$1
            shift
        ;;
        -l)
            SEG=$1
## TODO parse the info
            if [[ $SEG =~ .*:.* ]]; then
                ## two parameters
                LINE_L=${SEG%:*}
                LINE_R=${SEG##*:}
            else
                LINE_L=$SEG
                LINE_R=$SEG
            fi
            if (($LINE_L == 0)); then
                ER "LINE cannot be 0 sorry QQ"
            fi
            shift
        ;;
        *)
            DIR=$arg
        ;;
    esac
done

for i in $(find $DIR -type f); do
    if ! [[ $(basename $i) =~ $NAME_REGEX ]]; then
        continue
    fi
    echo "Processing file $(basename $i):"

    ALL=$(wc -l < $i)
    L=$LINE_L
    R=$LINE_R

    if (( $L < 0 )); then
        L=$((ALL+L+1))
        if (( $L < 0 )); then
            L=1
        fi
    fi

    if (( $R < 0 )); then
        R=$((ALL+R+1))
    fi

    if (( $L > $R )); then
        continue
    fi

    sed -n "${L},${R}p" < $i

done