Solaris command equivalents in Linux

[Kevin]

This is a question for any Solaris/Linux admins.

What (if any) are the Linux equivalents to the following Solaris commands:

1) pargs (Print process arguments, environmental variables, etc)
2) pcred (Display process credentials)
3) pfiles (Display open file info)
4) pldd (List dynamic libs associated to process)
5) pwdx (Display current working directory for process)

Thanks
  Kevin