Provided by: umview_0.6-1_i386 bug


       umview - User Mode implementation of View-OS


       umview [ options ] prog


       The  main  goal  of the View-OS project is to give each process its own
       view of the system resources.  For  example,  each  process  can  mount
       filesystems  or  hide  some file or directories. It is also possible to
       assign virtual network  interfaces,  IP  addresses  or  define  virtual
       devices for each process (or for hierarchies of processes).
       umview  is  the  user mode implementation of View-OS concepts.  It is a
       modular partial virtual machine.  umview before loading any  module  is
       completely  transparent,  a  process  behaves inside umview as it would
       have behaved outside.  Each module  can  customize  specific  entities:
       there  are  modules  to  mount  filesystems at user-level (umfuse) , to
       define virtual networks (umnet) , to define virtual devices  (umdev)  ,
       to  provide  interpreters  for executables, e.g. to support executables
       for foreign architectures (umbinfmt) , to hide, move, overlay parts  of
       the file system (viewfs).
       These  are  some  examples  of  modules  provided  by the View-OS team.
       umview aims to provide a general interface to customize the system call
       semantics  of  process under specified conditions. So more modules will
       be added both by the View-OS team and by third parties.
       umview  can  also  be  used  as  a  login  shell  in  /etc/passwd  (see
       passwd(5)).  When umview is a login shell the mapping between each user
       and his/her startup  script  is  in  the  file  /etc/viewospasswd  (see


       -f script-path
       --rcfile script-path
           Load  the  specified  startup  script  instead  of the standard one
           ($(HOME)/.viewosrc).  /etc/viewosrc is  always  loaded  first,  and
           then either $(HOME)/.viewosrc or the script specified by -fB or
       -V name
       --viewname name
           set the name of the view. The view can be read and set using vuname
           or viewname commands.
       -p module [ , module_options ]
       --preload module [ , module_options ]
           preload modules.  Modules will be loaded as shared  libraries  thus
           all  the rules to load libraries apply. Modules must be loaded from
           a directory within the search path or should be specified  by
           their   pathnames.   If  necessary  configure  the  LD_LIBRARY_PATH
           environment  variable  appropriately.   module_options  are  module
           specific  configuration  options,  thus  the reader should refer to
           each service module manual for a complete description.  Modules can
           be loaded at run time using the um_add_service command.
           umview is able to provide module nesting, i.e. a module can provide
           services on the basis  of  virtual  services  provided  by  another
           module  or even by the module itself. For example it is possible to
           mount a file system image which is stored in an  already  virtually
           mounted  filesystem.   This feature requires the pure_libc library.
           The -x or --nonesting option disables the nesting feature.
           umview is  able  to  use  some  specific  kernel  extensions  (when
           present)  to  increase  its performance. The source distribution of
           umview include the kernel patches  for  the  latest  kernels.   The
           kernel  extensions  are  enabled  by  default when available.  This
           option disables the kernel extensions.
           This option disables the PTRACE_MULTI kernel extension.
           This option disables the PTRACE_SYSVM kernel extension.
           This option disables the PTRACE_SYSVIEWOS kernel extension (already
           experimental, not yet released).
       -o file
       --output file
           This  option diverts the debugging output to the file specified, it
           is useful when umview has been compiled with debugging extensions.
           Print the version and exit.
           Print a short help message and exit.
           user startup scripts information for kmview login shells.
           global configuration script
           user configuration script (it is not automatically loaded  in  case
           of login shell. Add it at the end of the login script if needed)


       um_add_service(1),         um_del_service(1),         um_ls_service(1),
       um_mov_service(1),  umfuse(1viewos),  lwipv6(1viewos),  umdev(1viewos),
       umbinfmt(1viewos), viewfs(1viewos), vuname(1viewos), viewname(1viewos),


       View-OS is a project of the Computer Science Department, University  of
       Bologna.  Project Leader: Renzo Davoli. Development Team: P. Angelelli,
       A.  Bacchelli, M.  Belletti,  P.  Beverini,  D.  Billi,  A.  Forni,  L.
       Gardenghi,  A.  Gasparini,  D.  Lacamera,  C.  Martellini, A. Seraghiti

       Howto's and further information  can  be  found  on  the  project  wiki