Created attachment 624102 [details]
Allow smem to operate in the presence of unknown UIDs

Description of problem:

smem throws a KeyError exception if it encounters unknown user ids in the process table:

Traceback (most recent call last):
  File "/bin/smem", line 656, in <module>
    showusers()
  File "/bin/smem", line 396, in showusers
    showtable(pt.keys(), fields, columns.split(), options.sort or 'pss')
  File "/bin/smem", line 476, in showtable
    r = [fields[c][1](n) for c in columns]
  File "/bin/smem", line 375, in showuser
    return src.username(u)
  File "/bin/smem", line 63, in username
    self._ucache[uid] = pwd.getpwuid(uid)[0]
KeyError: 'getpwuid(): uid not found: 26'

While this is a rare situation on a legacy server, it is very common on a system using some sort of container-based virtualization such as LXC, where per-process namespaces mean that there's no guarantee that running processes are sharing the same source of user information.

Version-Release number of selected component (if applicable):

smem-1.0-3.fc17.noarch

Additional information:

The attached patch addresses this problem by generating a name for unknown UIDs of the form "unknown_<uid>" (e.g., "unknown_26").