wlog - Man Page
WinPR logging facility
Description
wLog is a configurable and flexible logging system used throughout WinPR and FreeRDP.
The primary concept is to have a hierarchy of loggers that can be be configured independently.
Appenders
WLog uses different appenders that define where the log output should be written to. If the application doesn't explicitly configure the appenders the below described variable WLOG_APPENDER can be used to choose one appender.
The following kind of appenders are available:
- Binary
Write the log data into a binary format file.
- Console
The console appender writes to the console. Depending of the operating system the application runs on, the output might be handled differently. For example on android log print would be used.
- File
The file appender writes the textual output to a file.
- Udp
This appender sends the logging messages to a pre-defined remote host via UDP.
If no target is set the default one 127.0.0.1:20000 is used. To receive the log messages one can use netcat. To receive the default target the following command can be used: nc -u 127.0.0.1 -p 20000 -l
- Syslog
Use syslog for outputting the debug messages.
- Journald
This appender outputs messages to journald.
Levels
The WLog are complementary, the higher level always includes the lower ones. The level list below is top down. Top the highest level.
- TRACE
print everything including packets dumps
- DEBUG
debug messages
- INFO
general information
- WARN
warnings
- ERROR
errors
- FATAL
fatal problems
- OFF
completely disable the wlog output
Formats
The format a logger prints has the following possible options:
- lv
log level
- mn
module name
- fl
file name
- fn
function
- ln
line number
- pid
process id
- tid
thread id
- yr
year
- mo
month
- dw
day of week
- hr
hour
- mi
minute
- se
second
- ml
millisecond
A maximum of 16 options can be used per format string.
An example that generally sets the WLOG_PREFIX for xfreerdp would look like: WLOG_PREFIX="pid=%pid:tid=%tid:fn=%fn -" xfreerdp /v:xxx
Environment
- WLOG_APPENDER
The kind of appender, the accepted values are: CONSOLE, FILE, BINARY, SYSLOG, JOURNALD or UDP
- WLOG_PREFIX
configure the prefix used for outputting the message (see Format for more details and examples)
- WLOG_LEVEL
the level to output messages for
- WLOG_FILTER
sets a filter for WLog messages. Only the filtered messages are printed. The format of the filter is a series of <logger name>:<level> separated by comas
example: WLOG_FILTER=core.channel:DEBUG,dummy:TRACE will display debug messages for the core.channel logger and trace level for the dummy logger
- WLOG_FILEAPPENDER_OUTPUT_FILE_PATH
When using the file appender it may contains the output log file's path
- WLOG_FILEAPPENDER_OUTPUT_FILE_NAME
When using the file appender it may contains the output log file's name
- WLOG_JOURNALD_ID
When using the systemd journal appender, this variable contains the id used with the journal (by default the executable's name)
- WLOG_UDP_TARGET
target to use for the UDP appender in the format host:port
Bugs
Please report any bugs using the bug reporting form on the FreeRDP web site
See Also
Additional information and the latest version is available at the web site: http://www.freerdp.com
Author
David Fort <contact@hardening-consulting.com> wrote this manpage from materials written by Bernhard Miklautz <bernhard.miklautz@thincast.com>.
Referenced By
freerdp-proxy(1), freerdp-shadow-cli(1), sdl-freerdp(1), wlfreerdp(1), xfreerdp(1).