lsuser

List system users in a clean, columnar layout.

Most operating systems do not provide a straightforward, consistent API for enumerating local user accounts. lsuser solves this by using raw POSIX libc calls (getpwent/setpwent/endpwent) to read the password database and present users in a readable table — or structured JSON for scripting.

Features

• Cross-platform — Works on macOS, Linux, and other Unix-likes via libc.
• Smart defaults — Filters out system accounts by default (UID < 500 on macOS, UID < 1000 or 65534 on Linux).
• Show all accounts — Use -a / --all to include system daemon users.
• Customizable columns — Choose which fields to display: USER, UID, GID, REAL_NAME, HOME, SHELL.
• JSON output — Use -J / --json for machine-readable output.
• No external commands — Does not parse /etc/passwd directly or shell out to dscl/getent.

Installation

cargo install lsuser

Or build from source:

git clone https://github.com/your-username/lsuser.git
cd lsuser
cargo build --release
cp target/release/lsuser ~/.local/bin/

Usage

lsuser [OPTIONS]

Examples

lsuser                     # list human users (default columns: USER, UID, HOME, SHELL)
lsuser -a                  # include system accounts
lsuser -o USER,UID,REAL_NAME  # custom columns
lsuser -O -J               # all columns as JSON