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siman /
Last active Nov 27, 2019
Useful Linux commands for server admins (Ubuntu)

Useful Linux Commands for Admins

Process manager + shows CPU and RAM usage


Disk usage - nice UI


View substrate-playground.ts
import { Substrate } from "../cli/substrate";
import { arrayToOneLineString, prettyClass, prettyEntity } from '../cli/printers';
import { AddClassSchemaInputType } from '../types/AddClassSchemaTypes';
const classId = 1
const entityId = 1
const schemaId = 0
// tslint:disable-next-line:max-func-body-length
async function main() {
View simple-pluralize.tsx
function pluralize(count: number | BN, singluarText: string, plularText?: string) {
count = typeof count !== 'number' ? count.toNumber() : count;
const plural = () => !plularText ? singluarText + 's' : singluarText;
const text = count === 1 ? singluarText : plural()
return <><b>{count}</b> {text}</>
siman /
Created Sep 17, 2019
Web3 Foundation tasks for blockchain hackathon. Kyiv, Sep 21-22, 2019.

Вознаграждение от Web3 Foundation в размере $500 получит команд(а/ы), которая предложит качественное решение на блокчейне фреймворке Substrate или же, если это решение связано с инфраструктурой Polkadot Network. В качестве примеров, могут быть проекты на такую тему:

  • Альтернативные реализации тех модулей (SRML), которые уже идут в составе Substrate. Например:
    • Упрощенный модуль для балансов "balances" без locking, vesting, etc.
    • Упрощенный модуль для голосования "voting" с квадратическим голосованием.
    • Альтернативная реализация модуля "treasury"
    • и т.д.
View joystream-podcast-episode-schema.json
"name": "PodcastEpisode",
"description": "Joystream class schema for a podcast episode",
"properties": [
"name": "title",
"type": "Text",
"required": true,
"maxTextLength": 100
siman / joystream-new-class.schema.json
Last active Sep 10, 2019
Joystream class JSON schema with example
View joystream-new-class.schema.json
"$schema": "",
"$id": "TODO: An URL of this schema. Ideally at Example:",
"title": "JoystreamNewClass",
"description": "JSON schema to describe a new class for Joystream network",
"type": "object",
"additionalProperties": false,
"required": [
// Copyright 2019 Jsgenesis.
// This is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Substrate. If not, see <>.
/// Update category
fn update_category(origin, category_id: CategoryId, new_archival_status: Option<bool>, new_deletion_status: Option<bool>) -> dispatch::Result {
// Check that its a valid signature
let who = ensure_signed(origin)?;
// Not signed by forum SUDO
// Get path from parent to root of category tree.
View failed-to-create-a-forum-category-joystream.log
2019-06-14 10:20:30 Pre-sealed block for proposal at 314. Hash now 0xc150f6008b89ddad85a1db7f2976d53e91589cc737ade8d2057df2d8b0c5ed89, previously 0x351a1639359a4abd3a48212b123983e058a19c8a281bd25e8c2176c05436e350.
Hash: given=b09cdf4b661fb442f526f1607a8eb10427d755bbd4af0130533de12cba5af141, expected=91cdf8fb9afc1ef94623dfe0fa413b700893f320a2fb0ddbf2be04cda8808549
stack backtrace:
0: substrate_panic_handler::set::{{closure}}::h41c84304a3d7b8c9 (0x10a7674a0)
1: std::panicking::rust_panic_with_hook::hfcf2d0777bc6c409 (0x10a8c6ad0)
2: std::panicking::begin_panic::hf60a109f4abac58e (0x10a469be4)
3: srml_executive::Executive<System,Block,Context,Payment,AllModules>::execute_block::h3266066fafbe65cf (0x10a43156c)
View joystream-forum-module-build-errors.log
$ ./
~/Work/jsgenesis/joystream-runtime/wasm ~/Work/jsgenesis/joystream-runtime
Compiling substrate-forum-module v0.1.0 (
error[E0432]: unresolved import `serde_derive`
--> /Users/siman/.cargo/git/checkouts/substrate-forum-module-45fcd172ed492bdc/9c0cf65/src/
216 | use serde_derive::{Serialize, Deserialize};
| ^^^^^^^^^^^^ use of undeclared type or module `serde_derive`
error[E0425]: cannot find function `ensure_signed` in this scope
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