# Functions
CurrentGroup looks up the current user's group by their primary group id's entry in /etc/passwd.
CurrentUser looks up the current user by their user id in /etc/passwd.
GetAdditionalGroups looks up a list of groups by name or group id against the given /etc/group formatted data.
GetAdditionalGroupsPath is a wrapper around GetAdditionalGroups that opens the groupPath given and gives it as an argument to GetAdditionalGroups.
GetExecUser parses a user specification string (using the passwd and group readers as sources for /etc/passwd and /etc/group data, respectively).
GetExecUserPath is a wrapper for GetExecUser.
LookupGid looks up a group by its group id in /etc/group.
LookupGroup looks up a group by its name in /etc/group.
LookupUid looks up a user by their user id in /etc/passwd.
LookupUser looks up a user by their username in /etc/passwd.
# Variables
ErrNoGroupEntries is returned if no matching entries were found in /etc/passwd.
ErrNoPasswdEntries is returned if no matching entries were found in /etc/group.
ErrRange is returned if a UID or GID is outside of the valid range.