old-stdout

@readwithai - X - blog - machine-aided reading - 📖⚡️🖋️

Get the old output from shell commands, if you use tmux.

This is vibe-coded but will become less so over time.

Motivation

It is quite natural to want to do thigns with the output of a command that you just run without having to rerun. If you have programmatic access to your shell scrollback, by using tmux this allows you to get output.

Alternatives and prior work

You could collect the outputs of previous commands into files using tee.

You could use something like jupyter which matains history.

Usage

Use tmux.

• oldout will show the output of the previous command.
• oldout 2 shows you the output from the penultimate command (etc).
• outdiff shows the difference between the last two outputs

You can use --command with oldout to include the command.

Nonstandard prompts

I use a two line prompt. I therefore provide quite general features ot change the prompt parsing.

Multi-line Prompts

For prompts that span multiple lines, set PROMPT_LENGTH in ~/.config/oldout.py.

# Example two-line prompt:
# ┌─[user@host]─[/current/path]
# └─$ command here

PROMPT_RE = r"^┌─"  # Match the first line of the prompt
PROMPT_LENGTH = 2   # Skip both prompt lines when extracting output

Complex Prompt Patterns

The PROMPT_RE (in ~/.config/oldout.py.) regex can handle unusual prompt formats

# Powerline/fancy prompts with symbols
PROMPT_RE = r"➜\s+\w+"

# Prompts with timestamps
PROMPT_RE = r"^\[\d{2}:\d{2}:\d{2}\]"

# Conditional prompts (different in different directories)
PROMPT_RE = r"(prod|dev|staging)>"

# Prompts with color codes (matches after ANSI sequences)
PROMPT_RE = r"\x1b\[[0-9;]*m.*\$"

About me

I am @readwithai. I create tools for reading, research and agency sometimes using the markdown editor Obsidian.

I also create a stream of tools that are related to carrying out my work.

I write about lots of things - including tools like this - on X. My blog is more about reading and research and agency.