Quick Usage — Command-Line Interface
Starting Joular Core
Run joularcore (Linux / macOS) or joularcore.exe (Windows). The program starts monitoring immediately and updates the terminal display once per second.
Linux (PC/server) — requires elevated access to read RAPL power files:
sudo joularcore
macOS — requires elevated access for powermetrics or run with sudo:
joularcore
Windows:
joularcore.exe
Raspberry Pi and SBC — no sudo needed:
joularcore
Press Ctrl+C to stop.
Default Output
With no arguments, Joular Core displays total power, CPU power, GPU power, and CPU usage — updated every second in place on the same terminal line:
⚡ Total 18.45 W | CPU 15.20 W | GPU 3.25 W | CPU Usage 24.60%
Common Use Cases
Monitor a specific process by PID
joularcore -p 1234
Output includes the power attributed to that process:
⚡ Total 18.45 W | CPU 15.20 W | GPU 3.25 W | CPU Usage 24.60% | PID 1.84 W
Monitor an application by name
joularcore -a firefox
Joular Core finds all processes whose name matches firefox and sums their attributed power:
⚡ Total 18.45 W | CPU 15.20 W | GPU 3.25 W | CPU Usage 24.60% | App 3.12 W (4 PIDs)
Write output to a CSV file
joularcore -f power.csv
A new row is appended every second. See Exporting Power Data for the exact CSV format.
Run silently and only write to CSV
joularcore -s -f power.csv
The -s flag suppresses terminal output while keeping all other outputs (CSV, ring buffer, API) active.
Show only CPU or only GPU power
joularcore -c cpu
joularcore -c gpu
Numeric-only output (for scripting and piping)
joularcore -i
Prints a single float (total power in watts) per line with no labels or formatting. Combined with -c, it prints only the selected component:
joularcore -c cpu -i
Expose power data over HTTP and WebSocket
joularcore --api-port 8080
Starts an HTTP server. GET http://localhost:8080/data returns the latest reading as JSON, and ws://localhost:8080/ws streams a new JSON reading every second.
Expose power data over a shared memory buffer ring
joularcore -r
Subtract idle CPU baseline for process attribution
# Auto-calibrate: measure idle power over 5 seconds, then start monitoring
joularcore -p 1234 --calibrate-cpu-idle-baseline
# Or supply a known baseline manually
joularcore -p 1234 --cpu-idle-baseline 4.5
Full Options Reference
See the Command Line Options page for a complete list of all flags and their descriptions.