mixman

Pipe-friendly CLI that trims verbose command output for logs and agent context.

Usage

random-command | mixman

When the upstream command must drive the shell exit code, prefer command mode:

mixman -- random-command

For the pipe form, enable pipefail in your shell (see Exit codes).

Behavior

• Reads all stdin, then outputs a mix of the first 25 and last 25 lines.
• When total lines are 50 or fewer, overlapping top/bottom ranges are not duplicated — you get every line once.
• Lines longer than 250 characters are truncated (no suffix).
• Empty stdin produces no output and exits immediately.

Examples

# 60 lines → first 25 + last 25 (50 lines)
seq 1 60 | mixman

# 30 lines → all 30 (top and bottom overlap, no duplicates)
seq 1 30 | mixman

# Truncate long lines
python3 -c "print('x' * 300)" | mixman

# Typical Expo pipeline
just validate | mixman

# Preserve upstream exit code (recommended for validate/release gates)
mixman -- just validate

Exit codes

Unix pipes only connect stdout between processes. A downstream filter like mixman cannot see the upstream exit code when used as cmd | mixman — the shell sets $? to the last command in the pipeline (mixman), which exits 0 after processing stdin successfully.

Recommended: run commands through mixman directly so exit codes propagate:

mixman -- just validate
echo $?   # non-zero when validate fails

Alternative: keep cmd | mixman and enable pipefail so the pipeline fails when any stage fails:

# bash / zsh
set -o pipefail
just validate | mixman
echo $?   # non-zero when validate fails

# one-off
bash -o pipefail -c 'just validate | mixman'

Without pipefail, exit 1 | mixman leaves $? at 0 even though the upstream command failed. That is shell pipeline semantics, not a mixman processing error.

Install

npm install -g mixman

Or link locally while developing:

cd /path/to/focus/cli/mixman
npm link

Publish

npm login
npm publish

License

MIT