Git – Blue Cog Blog

Trying the Python Secrets Module and a Non-Secret Gist

March 29, 2022March 29, 2022wmelvinLeave a comment

I have been aware of GitHub Gists for a while, but haven’t used them until now. This post is mainly to see how they work in this WordPress blog. I created a public gist and embedded the URL below.

	#!/usr/bin/env python3

	# https://docs.python.org/3/library/secrets.html

	import secrets

	s = secrets.token_urlsafe(15)
	n1 = secrets.randbelow(len(s))
	n2 = secrets.randbelow(len(s))

	a = '~!@#$%^&*()-_+=:;'
	a1 = secrets.choice(a)
	a2 = secrets.choice(a)

	t = s[:n1] + a1 + s[n1:]
	t = t[:n2] + a2 + t[n2:]

	print(t)

view raw try_secrets.py hosted with ❤ by GitHub

For a code sample, I picked a short Python script from when I was looking at the secrets module. This script generates a random password with some hard-coded attributes. It starts by getting a 15 character string from token_urlsafe (though the final result is not URL-safe). It then inserts two special characters, chosen at random from a sequence, at random positions in the string. If I want different attributes for the password (such as a different length, or different token) I just edit the script.

Looks like a secret gist can be embedded too, but that sure doesn’t keep it secret:


	# https://docs.pytest.org/en/stable/reference/reference.html#pytest-raises

	import pytest


	def f():
	raise SystemExit(1)


	def test_mytest():
	with pytest.raises(SystemExit):
	f()

view raw test_sysexit.py hosted with ❤ by GitHub

This code sample is from trying the pytest.raises method.

Installing Git From Source On Ubuntu

August 3, 2010wmelvinLeave a comment

Git is available from the Ubuntu repositories in the git-core, git-doc, and git-gui packages (there are other Git-related packages available but I think those three make up a basic installation). The package maintainer’s version tends to be behind the currently available version of Git. To have the latest features and fixes in Git it is necessary to install it from source. This is the process I use to install Git from source on Ubuntu 9.10 (karmic) and 10.04 (lucid):

Download the source archive from http://git-scm.com and extract it (I just extract it where it lands in my Downloads directory). Open a terminal in (or cd to) the extracted Git source directory (~/Downloads/git-1.7.2.1 as of my latest install).

Install required packages:

sudo apt-get install libcurl4-gnutls-dev libexpat1-dev libssl-dev gettext libz-dev asciidoc

Build and install Git and its documentation:

make prefix=/usr/local all doc
sudo make prefix=/usr/local install install-doc

If you don’t include the doc and install-doc tasks in the installation then the Git documentation will not be available via man pages or the git help command. If you don’t want the documentation then you can leave out those tasks and you won’t need to install the asciidoc package either. I prefer to have the documentation.

Tweaking the Bash Prompt

July 3, 2010wmelvinLeave a comment

A little Saturday morning tweaking.

Based on this post at railstips.org, I decided to adjust my Bash prompt by appending the following to my ~/.bashrc file:

#...

function parse_git_branch {
  ref=$(git symbolic-ref HEAD 2> /dev/null) || return
  echo "("${ref#refs/heads/}")"
}

BLACK="[33[0;30m]"
BLUE="[33[0;34m]"
VIOLET="[33[1;35m]"
CYAN="[33[0;36m]"

PS1="n[$CYANu@h:$BLUEw$VIOLET $(parse_git_branch)$BLACK]n$ "

The prompt will now show the name of the branch I am working in when the current directory is part of a Git repository. The original code used yellow, red, and green to highlight parts of the prompt. That messed with my mind when I ran RSpec and saw yellow and red when I was expecting all green. Rather than get used to it, I changed the colors. I also added some newlines to perhaps keep the command line neater when deep in a directory tree.

[Update 2010-07-23]

After running with the above settings for a while I decided I don’t care for the colors in the prompt. Don’t need the square brackets either. I do like seeing the current git branch. That simplifies things a bit.

#...

function parse_git_branch {
  ref=$(git symbolic-ref HEAD 2> /dev/null) || return
  echo "("${ref#refs/heads/}")"
}

PS1="nu@h:w  $(parse_git_branch)n$ "

[Update 2010-09-25]

Okay, maybe a little color…

#...

function parse_git_branch {
  ref=$(git symbolic-ref HEAD 2> /dev/null) || return
  echo "("${ref#refs/heads/}")"
}

VIOLET="[33[1;35m]"
NO_COLOR="[33[0;0m]"  

PS1="n$VIOLETu@h:w  $(parse_git_branch)$NO_COLORn$ "

See. I told you it was "tweaking."

Git Resources

March 2, 2010wmelvinLeave a comment

I have been learning to use Git. The following is a list of resources I found to be useful, interesting, or that I want to explore further as I get into Git:

Website: Git – Fast Version Control System – The home of Git. When you think source code management it’s only natural to picture a monster eating trees.