ACL_to_csv.js

const config = {
    filepath: "./file.log",
    line_delimiter: "\n",
    line_should_contain: "permit",
    to_remove: [/[\r\n]/g],
    original_column_delimiter: " ",
    columns_to_be_removed: [1, 2, -1, -2]
}

const fs = require('fs');
let file_data = fs.readFileSync(config.filepath, { encoding: 'utf-8' });
file_data = file_data.split(config.line_delimiter);
let new_file_data = file_data.filter((data) => {
    if (data.includes(config.line_should_contain))
        return true
    else
        return false
})
new_file_data.unshift("sep=,")
new_file_data = new_file_data.map((data) => {
    data = data.trim()
    config.to_remove.map((remove_data) => {
        data = data.replace(remove_data, "to_be_removed")
    })
    data = data.split(config.original_column_delimiter)
    config.columns_to_be_removed.map((column_no) => {
        if (column_no < 0)
            column_no = data.length + column_no
        data[column_no] = "to_be_removed"
    })

    data = data.join(",")
    data = data.replace(/,to_be_removed/g, "")
    //data = data.replace(/any/g, "any,")

    data = data.replace(/eq/g, ",eq")
    data = data.replace(/,host/g, "")
    data = data.split(",")


    if (data[5]) {
        data[5] = "," + data[5]
    }
    data = data.join(",")
    data = data.split(",")
    if (data[6]) {
        if (data[6].startsWith("255.255"))
            data[5] = "to_be_removed"
    }
    data = data.join(",")
    data = data.replace(/,to_be_removed/g, "")
    data = data.split(",")
    if (data[7])
        if (!/\d/.test(data[7]))
            //if (data[7].trim() != "")
            data[7] = "," + data[7]
    data = data.join(",")

    return data
});
console.log(new_file_data.join("\n"))