Provided by: umview_0.6-1_amd64 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 viewospasswd(5)).


       -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
       -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), viewospasswd(5)


       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 <>.