eml2mbx.js

/*
EML2MBOX, 2019-03-03, AGPL v3
https://www.reddit.com/user/jcunews1/

This script will convert one or more EML email files and combine them into a MBOX/MBX/MBS mailbox file.

Requirements:
  Windows  : Windows 95/NT4.
  Linux/Mac: WINE with Windows Script Host installed.

Usage:
  eml2mbx.js {target file} {source files...}
Or:
  cscript eml2mbx.js {target file} {source files...}

Examples:
  cscript eml2mbx.js messages.mbox *.eml
  eml2mbx.js messages.mbs "msg files\*.eml" temp\2019*.eml
*/



//UI-independent boolean prompt
function confirm(msg) {
  if (WScript.fullname.charAt(WScript.fullname.lastIndexOf("\\") + 1).toUpperCase() === "C") {
    WScript.stdout.write(msg);
    return WScript.stdin.readline().toUpperCase() === "Y";
  } else return (new ActiveXObject("wscript.shell")).popup(msg, 0, "EML2MBX", 36) === 6;
}

//UI-independent text display
function output(s, title, type) {
  if (WScript.fullname.charAt(WScript.fullname.lastIndexOf("\\") + 1) === "C") {
    WScript.stdout.write(s);
  } else (new ActiveXObject("wscript.shell")).popup(s, 0, title, type || 64);
}

function out(s, type) {
  output(s, "EML2MBX", type);
}

function help() {
  out("Usage: eml2mbx {target file} {source files...}");
  WScript.quit(1);
}

//split specified file path and returns the directory and file name in an array
function splitPath(s) {
  var b, i;
  if (s.charAt(1) === ":") {
    b = s.slice(0, 3);
    s = s.slice(3);
  } else if (s.slice(0, 2) === "\\\\") { //absolute remote path
    b = "\\\\";
    s = s.slice(2);
  } else b = "";
  if (s.charAt(s.length - 1) === "\\") s = s.slice(0, s.length - 1);
  if ((i = s.lastIndexOf("\\")) >= 0) {
    return [b + s.slice(0, i + 1), s.slice(i + 1)];
  } else return [b + ".\\", s];
}

//compare specified file name against a file mask
function matchMask(s, mask) {
  return (new RegExp("^" + mask.replace(/./g, function(a) {
    switch (a) {
      case "$":
      case "(":
      case "+":
      case ".":
      case "[":
      case "\\":
      case "^":
      case "{":
      case "|":
        return "\\" + a;
      case "*":
        return ".*?";
      case "?":
        return ".";
      default:
        return a;
    }
  }) + "$", "i")).test(s);
}

dt = null;
em = "";

function checkfield(s) {
  var i, m, d;
  s = s.replace(/\r?\n/g, " ").replace(/^\s+|\s+$/, "");;
  if ((s.slice(0, 9) === "Received:")) {
    i = s.lastIndexOf(";");
    if (i < 0) return;
    s = s.slice(i + 1).replace(/^\s+/, "");
    if (!s) return;
    d = new Date(s);
    if (!isNaN(d.getTime())) dt = d;
  } else if ((m = s.match(/^From:\s+(.*<([^>]+)|.*)/)) && !em) {
    em = m[2] || m[1];
  }
}

fs = new ActiveXObject("scripting.filesystemobject");
tfp = WScript.arguments(0);
sfs = [];
for (i = 1; i < WScript.arguments.length; i++) {
  fn = (pt = splitPath(WScript.arguments(i)))[1];
  pt = pt[0];
  try {
    dr = fs.getfolder(pt);
    pt = dr.path;
    if (pt.charAt(pt.length - 1) !== "\\") pt += "\\";
  } catch(z) {
    out("Path is inaccessible: " + pt, 16);
    WScript.quit(2);
  }
  sfs.push([pt, fn]);
}
if (!sfs.length || !tfp) help();
if (fs.fileexists(tfp) && !confirm("Target file is already exists.\nDo you want to overwrite it?")) WScript.quit(3);
try {
  tf = fs.createtextfile(tfp, true, false);
} catch(z) {
  out("Can not overwrite target file.", 16);
  WScript.quit(3);
}
cnt = 0;
for (i = 0; i < sfs.length; i++) {
  ls = new Enumerator(fs.getfolder(sfs[i][0]).files);
  for (; !ls.atEnd(); ls.moveNext()) {
    if (!matchMask(ls.item().name, sfs[i][1])) continue;
    try {
      sf = fs.opentextfile(ls.item().path, 1, false, 0);
    } catch(z) {
    }
    buf = "";
    hdr = "";
    dt = null;
    em = "";
    while (!sf.atendofstream) {
      s = sf.readline();
      if (s.charAt(0) !== " ") {
        hdr = s + "\r\n";
      } else hdr += s + "\r\n";
      checkfield(hdr);
      buf += s + "\r\n";
    }
    if (dt && em) {
      if (WScript.fullname.charAt(WScript.fullname.lastIndexOf("\\") + 1).toUpperCase() === "C") out(em + " " + dt.toDateString() + " " + dt.toTimeString().replace(/UTC/, ""));
      tf.writeline("From " + em + " " + dt.toDateString() + " " + dt.toTimeString().replace(/UTC/, "") + "\r\n" + buf);
    } else {
      if (!dt) {
        if (!em) {
          out("Missing received date and sender's email address in file: " + ls.item().path, 16);
        } else out("Missing received date in file: " + ls.item().path, 16);
      } else out("Missing sender's email address in file: " + ls.item().path, 16);
      WScript.quit(4);
    }
    sf.close();
    cnt++;
  }
}
out("\nProcessed " + cnt + " messages.");