NAME

       vudebug – debug utility for umvu

SYNOPSIS

       vudebug –help

       vudebug [debarg [debarg ...]] [ – command [args]]

       where debarg has the following syntax:

       +[tag[tag ...]][:colorspec]

       or

       -[tag[tag ...]]

       or

       ?[tag[tag ...]]

       and colorspec is a combination of the following characters: nwrgbcmyNWRGBCMY+-_*#

DESCRIPTION

       vudebug  enables  or  disables  debug  log  messages.  Log messages are classified into categories.  Each
       category is identified by a tag (one alphanumeric character).  By convention lowercase  letters  are  for
       logging messages of the hypervisor, while capital letters are for modules.

       When  vudebug  command line ends with -- followed by a command and its command line arguments, logging is
       enabled for the execution of  that  command  (and  for  all  the  subprocesses  it  eventually  creates).
       Otherwise vudebug changes the categories to log globally, for all the processes.

OPTIONS

       --help Print a short help message and exit.

       debarg each  debug argument begins by +, - or ? followed by zero, one or more debug tags.  (+ enables log
              messages, - disables log messages, ? check if the log  messages  are  enabled).   When  the  debug
              argument  has no tags, it is applied to all the tags.  Log messages of different categories can be
              shown in different colors and font effects.  When vudebug is used  to  enable/re-enable  tags  (+)
              each  debarg  can be followed by a semicolon (:) and a color specification.  A color specification
              is a string composed by the following characters:

              n w r g b c m y: set foreground color (black, white, red, green, blue, cyan, magenta or yellow)

              N W R G B C M Y: set background color (black, white, red, green, blue, cyan, magenta or yellow)

              + - _ * #: font effect (bright, dim,underlined, blinking, reverse video).

EXAMPLES

       Get a list of available logging categories:

              $ vudebug ?
              D -   VUDEV
              F -   VUFUSE
              N -   VUNET
              a -   ACTION
              c -   CHOICE
              f -   FILETABLE
              m -   MODULE
              n -   NESTED
              p -   PATH
              s -   SYSCALL
              v -   VNODE

       the list may vary depending on the version of the hypervisor and the modules currently loaded.

       Enable path resolution logging:

              $ vudebug +p

       List some categories to see which ones are active:

              $ vudebug ?ps
              p +   PATH
              s -   SYSCALL

       PATH is active, SYSCALL is not active.

       Disable all the categories:

              $ vudebug -

       Launch a bash and log syscall requests in red, path resolution in bold-blue,  module  choice  in  reverse
       green:

              $ vudebug +s:r +p:b+ +c:g# -- bash

SEE ALSO

       umvu(1)

AUTHOR

       VirtualSquare.  Project leader: Renzo Davoli

VirtualSquare-VUOS                                January 2024                                        VUDEBUG(1)