Unsupported SysV option when invoking ps

Question

I've installed Ubuntu 11.10 today. Every time I invoke ps, no matter what option I use, it always says

ERROR: Unsupported SysV option.

and then prints the help.

Do you know how to make ps work correctly or what is happening?

Answer 1

Do you maybe have an alias for ps that has some invalid options?

Check by running alias on a terminal.

Also, ensure that you're running the correct ps and not a version installed elsewhere. ps should be in /bin/ps and dpkg -S /bin/ps should say it belongs to the procps package.

Finally, if you really want to ensure your ps is what it should be, install debsums and do

debsums procps

it should return 'OK' for all files in the package.