bulkrename for lf filemanager

lfbulkrename.sh

#!/usr/bin/env zsh

print_usage() {
    if [ -z "$1" ] || [ -z "$2" ]; then
        echo "usage: lfbulkrename <lfid> <files_separated_by_newline>"
        exit
    fi
}

lfecho() {
    lf -remote "send $1 echoerr ${@:2}"
}

lfbulkrename() {
    print_usage $@

    lfid=$1
    input_files="${@:2}"

    buffer=/dev/shm/lfbulkrename

    echo "$input_files" > $buffer
    $EDITOR $buffer
    output_files=$(cat $buffer)
    
    len_in=$(echo "$input_files" | wc -l)
    len_out=$(echo "$output_files" | wc -l)
    if [ $len_in != $len_out ]; then
        lfecho $lfid "number of lines has to be the same in input and output"
        return
    fi

    for i in {1..$len_in}; do
        get_line="${i}q;d"
        in="$(echo $input_files | sed -e $get_line | tr -d \\n)"
        out="$(echo $output_files | sed -e $get_line | tr -d \\n)"
    
        if [ "$in" = "$out" ]; then
            lfecho $lfid "no change: $in"
            continue
        fi

        if [ -f "$out" ]; then
            lfecho $lfid "file exists: $out"
            continue
        fi

    
        mv "$in" "$out"
    done
}

lfbulkrename "$@"