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mktor/lstor/chtor

The following tools are grouped together due to their similar functionality. They can create, view, and modify .torrent files respectively.

lstor

lstor is used for displaying information about torrents. Without any flags, it shows a human-friendly summary of the torrent:

$ lstor ubuntu-22.04-desktop-amd64.iso.torrent
NAME ubuntu-22.04-desktop-amd64.iso.torrent
SIZE 3.4 GiB (13942 * 256.0 KiB + 142.0 KiB)
META 272.7 KiB (pieces 272.3 KiB 99.9%)
HASH 2C6B6858D61DA9543D4231A71DB4B1C9264B0685
URL  https://torrent.ubuntu.com/announce
PRV  NO (DHT/PEX enabled)
TIME 2022-04-21 10:22:56
BY   mktorrent 1.1
REM  Ubuntu CD releases.ubuntu.com

FILE LISTING
ubuntu-22.04-desktop-amd64.iso                                         3.4 GiB

However, you can also display the same information in JSON format with the --raw flag: 

lstor ubuntu-22.04-desktop-amd64.iso.torrent --raw

{
  "announce": "https://torrent.ubuntu.com/announce",
  "announce-list": [
    [
      "https://torrent.ubuntu.com/announce"
    ],
    [
      "https://ipv6.torrent.ubuntu.com/announce"
    ]
  ],
  "comment": "Ubuntu CD releases.ubuntu.com",
  "created by": "mktorrent 1.1",
  "creation date": 1650550976,
  "info": {
    "length": 3654957056,
    "name": "ubuntu-22.04-desktop-amd64.iso",
    "piece length": 262144,
    "pieces": "<13943 piece hashes>"
  }
}

If you only need to extract a few fields, the -o/--output flag lets you specify which fields to show:

$ lstor -o info.name,__size__ ubuntu-22.04-desktop-amd64.iso.torrent
ubuntu-22.04-desktop-amd64.iso  3654957056

Note

__size__ is a magic variable that tells lstor to sum the sizes of all files in the torrent. See lstor --help for all the supported magic variables.

By default lstor will throw an error if the file isn't a valid .torrent file. However, if you wish to ignore those errors (to view a rTorrent session file, for instance), the --raw flag can be combined with -V/--skip-validation.

lstor can also hash check the torrent against real data by using the -c <path> flag.

mktor

At its simplest, creating a torrent file requires only a path and an announce URL:

date > date.txt
mktor date.txt http://tracker.publicbt.com:80/announce

If you have aliases configured, you can use the alias in place of the URL.

config.toml
[ALIASES]
PUB_BT = ["http://tracker.publicbt.com:80/announce"]

mktor date.txt PUB_BT

Cross-seeding

To avoid duplicating the same hash across private trackers, mktor has two mechanisms to add distinct data to the info dictionary:

  • source gets set to the tracker alias (if available), or the 2nd level domain if not available
  • x_cross_seed gets set to an MD5 hash of the URL

If you don't want one or both of these fields present, you can use the -s/--set flag to have them removed:

mktor --set info.source --set info.x_cross_seed date.txt http://tracker.publicbt.com:80/announce

chtor

If you have an existing .torrent file you'd like to change, whether created by mktor or an entirely different program, chtor is your friend.

Warning

Changing any fields in the info section of the data will change the torrent hash, which may have unintended consequences.

The simplest way to change data is the -s/--set flag, which can add, change, or remove fields:

date > date.txt
mktor date.txt http://tracker.publicbt.com:80/announce
lstor --raw date.torrent
chtor --set "last changed=$(date)" date.torrent # Add \
  --set "created by=PyroSimple v2" # Change \
  --set "creation date=" # Remove
lstor --raw date.torrent

There's also a similar flag to set fields with a regex:

chtor --regex "created by/PyroSimple/PyroChanged/" date.torrent

There are many other flags available to perform common operations, such as removing non-standard fields (--clean) or adding fast resume data (--datapath <DATA>).