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