Q&A with Self-built Blockchain and Dapps (2)
Tags: homebrew, webdev, codenewbie
Published: 2022-06-20 16:13:34

> The purpose of building this blog is to write down my memo for learning the dApps.

### Q1: brew no such file or directory?

When I want to remote access to my PC, it always tells me that brew is not properly installed.
How do i fix this problem?

`-bash: /bin/brew: No such file or directory`
`-bash: /bin/brew: No such file or directory`

### A1:
Try uninstalling Homebrew and then re-installing solved issue for me.

Uninstall Homebrew:
```linux
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/uninstall.sh)"
```
Re-install Homebrew:
```linux
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
```
And better to update afterwards:
```linux
sudo apt update
sudo apt upgrade
```
---
### Q2: What is the connection between IPFS and Filecoin?

### A2:
Filecoin and IPFS are two separate, complementary protocols, both created by Protocol Labs. IPFS allows peers to store, request, and transfer verifiable data with each other, while Filecoin is designed to provide a system of persistent data storage. Under Filecoin's incentive structure, clients pay to store data at specific levels of redundancy and availability, and storage providers earn payments and rewards by continuously storing data and cryptographically proving it.

In short: IPFS addresses and moves content, while Filecoin is an incentive layer to persist data.

These components are separable - you can use one without the other, and IPFS already supports more self-organized or altruistic forms of data persistence via tools like IPFS Cluster (opens new window). Compatibility between IPFS and Filecoin is intended to be as seamless as possible, but we expect it to evolve. You can view the draft spec for IPFS-Filecoin Interoperability (opens new window)and ideas for future improvements (opens new window)to learn more.

### Q3: Mining process

### A3:

Mining is the process of recording the pending transaction by adding a new Block into the BlockChain through a mathematical puzzle. Miners get rewarded for by receiving the new crypto coins of that Blockchain.

Mining rewards are given to the miner who first finds the solution to a complicated hashing problem, and the chance of a miner finding the solution is proportional to the portion of the network's overall mining capacity.

Miners need to solve a mathematical problem when trying to add a block to the blockchain.

Block can only be added to the blockchain if its signature that is the hash output starts with a certain amount of zeros.

If the data string of the block does not generate to a signature that start with so many consecutive zeros, miners will keep changing the nonce endlessly until they randomly hit an output string that matches the signature requirements.

In mining a block is added to the blockchain after miner validates this block and confirms it.

The process of mining is not mandatory for a blockchain to exist. The mining concept is a way of validation for the transactions; that is why most public blockchains use it.

### References
https://docs.ipfs.io/concepts/faq/#ipfs-and-filecoin
https://www.investopedia.com/tech/how-does-bitcoin-mining-work/
cover image:
https://stock.adobe.com/ca/search?k=q%26a&asset_id=431829099