Simon Willison's Weblog: bash

How to add a directory to your PATH

2025-02-14T02:40:11+00:00

Classic Julia Evans piece here, answering a question which you might assume is obvious but very much isn't.

Plenty of useful tips in here, plus the best explanation I've ever seen of the three different Bash configuration options:

Bash has three possible config files: ~/.bashrc, ~/.bash_profile, and ~/.profile.

If you're not sure which one your system is set up to use, I'd recommend testing this way:

add echo hi there to your ~/.bashrc

Restart your terminal

If you see "hi there", that means ~/.bashrc is being used! Hooray!

Otherwise remove it and try the same thing with ~/.bash_profile

You can also try ~/.profile if the first two options don't work.

This article also reminded me to try which -a again, which gave me this confusing result for datasette:

% which -a datasette
/opt/homebrew/Caskroom/miniconda/base/bin/datasette
/Users/simon/.local/bin/datasette
/Users/simon/.local/bin/datasette

Why is the second path in there twice? I figured out how to use rg to search just the dot-files in my home directory:

rg local/bin -g '/.*' --max-depth 1

And found that I have both a .zshrc and .zprofile file that are adding that to my path:

.zshrc.backup
4:export PATH="$PATH:/Users/simon/.local/bin"

.zprofile
5:export PATH="$PATH:/Users/simon/.local/bin"

.zshrc
7:export PATH="$PATH:/Users/simon/.local/bin"

Tags: bash, julia-evans, ripgrep, zsh

3 shell scripts to improve your writing, or "My Ph.D. advisor rewrote himself in bash."

2024-12-14T18:20:50+00:00

3 shell scripts to improve your writing, or "My Ph.D. advisor rewrote himself in bash."

Matt Might in 2010:

The hardest part of advising Ph.D. students is teaching them how to write.

Fortunately, I've seen patterns emerge over the past couple years.

So, I've decided to replace myself with a shell script.

In particular, I've created shell scripts for catching three problems:

abuse of the passive voice,

weasel words, and

lexical illusions.

"Lexical illusions" here refers to the thing where you accidentally repeat a word word twice without realizing, which is particularly hard to spot if the repetition spans a line break.

Matt shares Bash scripts that he added to a LaTeX build system to identify these problems.

I pasted his entire article into Claude and asked it to build me an HTML+JavaScript artifact implementing the rules from those scripts. After a couple more iterations (I pasted in some feedback comments from Hacker News) I now have an actually quite useful little web tool:

tools.simonwillison.net/writing-style

Here's the source code and commit history.

Via lobste.rs

Tags: bash, tools, writing, ai, generative-ai, llms, ai-assisted-programming, claude-artifacts, prompt-to-app

Running prompts against images and PDFs with Google Gemini

2024-10-23T18:25:07+00:00

Running prompts against images and PDFs with Google Gemini

New TIL. I've been experimenting with the Google Gemini APIs for running prompts against images and PDFs (in preparation for finally adding multi-modal support to LLM) - here are my notes on how to send images or PDF files to their API using curl and the base64 -i macOS command.

I figured out the curl incantation first and then got Claude to build me a Bash script that I can execute like this:

prompt-gemini 'extract text' example-handwriting.jpg

Playing with this is really fun. The Gemini models charge less than 1/10th of a cent per image, so it's really inexpensive to try them out.

Tags: bash, google, ocr, projects, ai, generative-ai, llms, ai-assisted-programming, llm, gemini, vision-llms, llm-pricing

lsix

2024-06-06T22:07:35+00:00

lsix

This is pretty magic: an ls style tool which shows actual thumbnails of every image in the current folder, implemented as a Bash script.

To get this working on macOS I had to update to a more recent Bash (brew install bash) and switch to iTerm2 due to the need for a Sixel compatible terminal.

Via Hacker News

Tags: bash

Quoting tailscale.com/install.sh

2024-04-29T21:00:27+00:00

# All the code is wrapped in a main function that gets called at the bottom of the file, so that a truncated partial download doesn't end up executing half a script.

— tailscale.com/install.sh

Tags: bash, tailscale

A tiny CI system

2022-04-26T15:39:27+00:00

A tiny CI system

Christian Ştefănescu shares a recipe for building a tiny self-hosted CI system using Git and Redis. A post-receive hook runs when a commit is pushed to the repo and uses redis-cli to push jobs to a list. Then a separate bash script runs a loop with a blocking “redis-cli blpop jobs” operation which waits for new jobs and then executes the CI job as a shell script.

Via @stchris_

Tags: bash, continuous-integration, git, redis

flk: A LISP that runs wherever Bash is

2019-12-04T05:19:25+00:00

flk: A LISP that runs wherever Bash is

This is a heck of a project: an implementation of LISP written entirely in Bash, meaning you can run it as a script on any machine that has a Bash installation.

Via Hacker News

Tags: bash, lisp

direnv

2017-11-05T19:59:35+00:00

direnv

A shell extension (for bash, zsh and others) which can automatically set and unset environment variables when you cd into specific directories. Useful for managing things like a project’s GOPATH or automatically activating Python virtual environments.

Via Go at DigitalOcean

Tags: bash, shell, zsh

What is a good programming language to learn after bash scripting?

2012-01-13T16:45:00+00:00

My answer to What is a good programming language to learn after bash scripting? on Quora

Python is a good natural progression from bash in my opinion. It has an interactive prompt which supports bash-style exploratory programming, and it has libraries that mean it can be applied to an enormous range of problems - everything from game development to scientific computing to web applications.

Tags: bash, programming, shell, quora

Using Bash's History Effectively

2010-02-25T12:21:09+00:00

Using Bash's History Effectively

The HISTIGNORE environment variable is particularly useful, allowing you to suppress certain commands by specifying a pattern. This article has a tip for causing a command to be omitted from the history if you prefix it with a space.

Tags: bash

shunit2

2009-09-27T19:34:03+00:00

shunit2

xUnit style testing for shell scripts.

Via Jacob Kaplan-Moss

Tags: bash, shell, shunit2, testing, unix, xunit

BashReduce

2009-06-28T15:03:15+00:00

BashReduce

Map/Reduce in Bash is no longer a joke project (if it ever was)—Richard Crowley is extending it and using it for analysis at OpenDNS.

Tags: bash, bashreduce, mapreduce, opendns, richard-crowley

resty

2009-05-18T13:07:09+00:00

resty

58 lines of bash provides a better command-line interface to RESTful APIs, using curl under the hood. This should save me from running “man curl” several times a week.

Tags: apis, bash, cli, curl, rest, resty