XTRACE(1) XTRACE XTRACE(1)
NAME
xtrace - trace communication between X11 client and server
SYNOPSIS
xtrace [ options ] [ -s | -k ] [ [ -W ] [ -- ] command args ... ]
DESCRIPTION
Xtrace fakes an X server and forwards all connections to a real X server, displaying the communication between clients in (well, theoreti-
cally) human readable form. If a command is given, xtrace executes the named command with $DISPLAY set to the faked X server. If that com-
mand exits before any connections are made, xtrace exits immediately unless -W is specified.
OPTIONS
-I directory
Look into directory for protocol description files. (i.e. the directory where the .proto files can be found).
-s | --stopwhendone (default)
Terminate when all forwarded clients have disconnected. (Or when a program was run once the program has finished and all connec-
tions are closed).
-k | --keeprunning
If all clients disconnected, wait for new ones to connect.
-W | --waitforclient
Do not stop when the started program terminates before any connection was made. (Might be necessary if the program forks to back-
ground).
-d name | --display name
Forward connections to the X server specified by name instead of the one specified by the environment variable DISPLAY.
-D name | --fakedisplay name
Fake display name instead of $FAKEDISPLAY or :9 respectively.
-f filename | --authfile filename
Add an -f filename to the arguments for all calls to xauth to get the authentication tokens of the X server to connect to.
-F filename | --newauthfile filename
Add an -f filename to the arguments for all calls to xauth to save the authentication tokens to connect to the faked X server.
-c | --copyauthentication (default)
Copy the authentication tokens for the X server to connect to so that clients connecting to our fake server will use them.
The commands run are roughly equivalent to: xauth add $FAKEDISPLAY . `xauth list $DISPLAY | awk '$2=="MIT-MAGIC-COOKIE-1" {print
$3}'`
Not that only MIT-MAGIC-COOKIE-1 tokens are copied as xtrace does not yet support to change the authentication tokens so that XDM-
AUTHORIZATION-1 would be possible.
-n | --nocopyauthentication
Do not call xauth and do fiddle with authentication tokens but leave that to the user to handle.
-e | --denyextensions
Modify all server replies to say there are no extensions available. (As xtrace does supports only a small number of extensions any-
way and calls all extended requests "unknown" and all replies to such requests "unexpected").
-w | --readwritedebug
Print how many bytes are read and/or written when.
-m count | --maxklistlength count
Print only the first count many elements of all lists.
-i | --interactive
Only sent requests from the client to the server after interactive confirmation. Confirmation is given by pressing enter or a num-
ber followed by enter via stdin. This can give funny results when multiple clients are tunneled.
-o | --outfile filename
Dump output into filename instead of stdout.
-b | --buffered
Do not write every line on its own but wait until buffers are full. Speeds up things a little bit when outputting to a file. Not
very useful at all together with -i.
--timestamps
Print a timestamp before each line.
Note that the time a packet is printed is between the time a packet is received and the time a packet is sent, but it gives no other
information than that.
--relative-timestamps
Print a timestamp relative to the beginning of the connection before each line.
Note that the time a packet is printed is between the time a packet is received and the time a packet is sent, but it gives no other
information than that.
--monotonic-timestamps
Print a CLOCK_MONOTONIC (see clock_gettime(3)) timestamp each time a package is printed. This is likely to be the uptime of your
system.
Note that the time a packet is printed is between the time a packet is received and the time a packet is sent, but it gives no other
information than that.
--print-offsets
Print offsets of all fields (useful to debug nested lists in protocol descriptions)
--print-counts
Print counts (useful to debug lists in protocol descriptions)
ENVIRONMENT VARIABLES
DISPLAY
Without --display the content of this variable is used to determine the server to connect to. (And without -n given to xauth to get
the authentication tokens for this display.)
FAKEDISPLAY
Without --fakedisplay the content of this variable is used to determine how to listen for clients. (And without -n given to xauth to
set the authentication tokens for this display.) If neither is given, xtrace will try :9
XAUTHORITY
Without -n and without -f or -F your xauth program will most likely look into this variable for the file to get/save the authentica-
tion tokens from/into. If this is not set it will most likely use $HOME/.Xauthority.
REPORTING BUGS
Report bugs to <brlink@debian.org> or the Debian BTS.
SEE ALSO
xauth(1), x(7x),
COPYRIGHT
Copyright (C) 2005 Bernhard R. Link
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
LAR PURPOSE.
xtrace 26 June 2009 XTRACE(1)