Using Grep Properly To Search In Files

I have mentioned a number of times that I make heavy use of Docker to spin up instances of infrastructure I use in development, like databases.

For example, here is the docker-compose.yaml for my Microsoft SQL Server that persists data to disk:

services:
  sql_server:
    image: mcr.microsoft.com/mssql/server:2022-latest
    container_name: sql_server_2022
    restart: always
    environment:
      - ACCEPT_EULA=Y
      - SA_PASSWORD=2PA@YLi9aTNi_6KPowm
      - TZ=Africa/Nairobi
    ports:
      - '1433:1433'
    volumes:
      - /Users/rad/Data/SQLServer2022:/var/opt/mssql/data

I routinely forget the SA password, so when I need to retrieve it, I have been doing this using the ripgrep utility :

cat docker-compose.yaml | rg SA_PASSWORD

Which prints what I expect:

Much as it is working, I am in fact doing the wrong thing.

What this does is:

1. Load the entire file from disk
2. Pipe the content to ripgrep
3. Ripgrep then filters what I want
4. The result is printed to the terminal

This is unnecessary because ripgrep directly supports searching in files.

I can achieve the same thing with a single command like this:

rg SA_PASSWORD docker-compose.yaml

This returns the following:

In addition to being simpler and faster, this approach also has the added benefit of returning the line number.

The same will work with whichever flavour of grep you use, plain vanilla grep, ripgrep, or ugrep.

TLDR

Grep (and its flavours) directly support searching in files, so piping cat to grep is unnecessary.

Happy hacking!