Linux Exit Code Lookup

137 = 128 + 9, meaning the process received signal 9 (SIGKILL). In containers this almost always means the OOM (out-of-memory) killer terminated the process because it exceeded its memory limit, or something ran `docker kill`/`kill -9` on it directly.

There is no universal standard distinguishing them, but by convention many tools use 1 as a generic "something went wrong" error and 2 specifically for incorrect command usage (wrong flags or arguments) in shell builtins, though individual programs are free to define their own meanings.

130 = 128 + 2, and signal 2 is SIGINT, which is exactly the signal your terminal sends when you press Ctrl+C. Seeing 130 reliably tells you the process was interactively interrupted rather than crashing on its own.

No — exit codes are stored in a single byte by the OS, so any value is automatically wrapped modulo 256 (e.g. exiting with 256 actually reports as 0, and -1 reports as 255), which is why code 255 is treated as "exit status out of range."

No — it is a pure client-side reference and calculator; type a number to see its known meaning, or search the table. Nothing is executed on your machine or sent anywhere.