socatui

A task-manager style TUI (Rust + ratatui) for running and monitoring multiple socat relays. Each tunnel is one socat --statistics [options] SOURCE DESTINATION process; the list shows its status, PID, active connections, bytes transferred in each direction, live throughput and uptime, refreshed once per second.

Requirements

• socat 1.8.0 or newer in PATH (the --statistics option and SIGUSR1 stat dumps were introduced in 1.8).
• macOS or Linux (uses ps and POSIX signals).

Build and run

cargo build --release
./target/release/socatui                # uses ~/.config/socatui/tunnels.json
./target/release/socatui my-tunnels.json
SOCATUI_CONFIG=/path/tunnels.json ./target/release/socatui

Keys

In the add/edit form: Tab/↑/↓ move between fields, Space toggles Autostart, Enter saves, Esc cancels.

Tunnel definition

Source and destination are passed to socat verbatim as single arguments, so no shell quoting is needed (or applied). Definitions are stored as JSON in the config file and saved on every add/edit/delete/reorder.

How the statistics work

socat 1.8 logs its transfer counters to stderr when it exits and whenever it receives SIGUSR1:

socat[75527] I STATISTICS: left to right: 1 packets(s), 5000 byte(s)
socat[75527] I STATISTICS: right to left: 1 packets(s), 5000 byte(s)

Once per second socatui walks the process tree under each tunnel, sends SIGUSR1 to every socat process in it (not to programs started via EXEC:/SYSTEM:, which would die on that signal), and parses the lines that come back on stderr. With the fork option every connection is a separate socat child with its own counters, so counters are tracked per PID and summed; finished children are folded into an archived total after a short grace period so that PID reuse cannot lose bytes. CONN is the number of live forked workers, and throughput is the delta between consecutive samples.

All other stderr output from socat (errors, -d diagnostics, exit status) is shown in the log pane for the selected tunnel. The last 500 lines per tunnel are kept in memory.

Exporting logs

w exports the selected tunnel's log, W exports every tunnel's log. The dialog is prefilled with a random path such as /tmp/socatui-echo-relay-1758640000-a3f9c1.log; press Enter to write it there, or type another path first (Ctrl-U clears the field, Tab switches between the selected tunnel and all tunnels). Each tunnel section starts with a header giving the status, the exact socat command line, the PID and the transfer counters, followed by the retained log lines.