YAWS(1) User Commands YAWS(1)NAMEyaws - yet another webserver
SYNOPSISyaws [OPTIONS]
DESCRIPTION
Yaws is fast lightweight webserver. It can run as daemon or in interac‐
tive mode where it is possible to directly interact with the webserver.
Yaws is particularly good at generating dynamic content. See the user
docs for more information on that topic.
DAEMON/SERVER options
-i | --interactive
Interactive mode. This will start yaws in interactive mode with
an erlang prompt. All error_logger messages will be written to
the tty as well in this mode. Use this when developing yaws
code.
-w | --winteractive
Cygwin inteactive mode (werl)
-D | --daemon
Daemon mode. This will start yaws as a daemon.
--heart
This will cause the yaws system to be automatically restarted in
case it should crash. This switch also requires the --daemon
switch to be present.
--heart-restart=C,T
This controls the number of restarts in a given time period that
heart tolerates before refusing to restart Yaws. By default,
heart allows up to 5 restarts within a 60 second period before
refusing to restart Yaws again. This option allows up to C
restarts in T seconds instead. To allow infinite restarts, set
both C and T to 0. This switch automatically enables the --heart
switch.
--debug
Debug mode. This will produce some auxiliary error output for
some error conditions. It will also start the otp sasl lib for
additional error printouts.
--nodebug
Non-debug mode. This is useful for running interactively via the
-i option but without incurring the performance penalties of
debug mode.
--conf file
Use a different configuration file than the default. If the con‐
figuration parameter config is set, yaws use it as default con‐
figuration file. Else, The default configuration file when run‐
ning as root is /etc/yaws/yaws.conf. When running as a non priv‐
iliged user, yaws will search for its configuration file in the
following order. First in $HOME/yaws.conf, then in ./yaws.conf
and finally in /etc/yaws/yaws.conf.
--runmod module
Tells yaws to call module:start/0 at startup. This makes it pos‐
sible to startup user specific applications together with yaws.
--pa path
Add path to the yaws system search path
--tracetraf
Traffic trace mode. All traffic will be written to a trace file
called trace.traffic in the log directory.
--tracehttp
HTTP trace mode. All HTTP messages will be written to a trace
file called trace.http in the log directory.
--traceout
When yaws is put into trace mode using either --tracetraf or
--tracehttp, traces are written to files. If we provide the
--traceout flag, the trace will also be written to stdout.
--trace
Sames as --tracetraf --traceout. I.e. trace everything and write
to stdout.
--mnesiadir dir
Start Mnesia in directory <dir>
--sname xxx
Start yaws as a distributed erlang node with name <xxx> using
the unqualified hostname as nodename postfix
--disable-kpoll
By default, yaws starts erlang with +K true. This flag reverses
that.
--name xxx
Start yaws as a distributed erlang node with name <xxx> using
the fully qualified hostname as nodename postfix
--proto_dist Mod
Use module Mod for erlang distribution. This is typically only
used when we want to run erlang distribution over SSL.
--erlarg STRING
Pass STRING as an additional argument to the "erl" program. If
STRING comprises multiple words, you must quote it so that your
shell passes it to yaws as a single argument. If STRING contains
any single quote characters, you must quote each of them as
well. For example, to pass the option -env NAME O'Keeffe to
"erl" from a Bourne-compatible shell:
--erlarg "-env NAME O\'Keeffe"
--id ID
This flag sets the id. If we're starting a daemon (or an inter‐
active system) it gives the Yaws server the identity ID. This
means that the server will write all internal files into the
directory $HOME/.yaws/yaws/ID.
Yaws also creates a file called $HOME/.yaws/yaws/ID/CTL which
contains the portnumber the daemon is listening on for control
request by the control command such as "yaws --hup" etc.
If we're invoking a control command which should perform some
control function on the daemon, we may have to give the --id
flag also to the control command. If we don't do this the con‐
trol command may interact with the wrong daemon due to finding
the wrong "ctl" file.
The daemon may also optionally specify the "id" in the yaws.conf
configuration file.
--umask MASK
Set the umask for the daemon to MASK.
CONTROL OPTIONS
The following list of options are are used to control the daemon from
the "outside" while it is running.
--hup [--id ID]
HUP the daemon. This forces the daemon to reread the configura‐
tion file. It also makes the daemon empty all its internal con‐
tent caches. Hence when updating the doc root, HUPing the dae‐
mon is the fastest way to see the content updates.
--stop [--id id]
Stop the daemon (called id)
--ls Lists current ids and status of all yaws servers on localhost.
In practice this amounts to a listdir in $HOME/.yaws/yaws - and
check whether the different systems who has created files there
are alive.
--status [--id id]
Query a running yaws daemon for its status, and print it.
--stats [--id id]
Query a running yaws daemon for its statistics, and print it.
--running-config [--id id]
Query a running yaws daemon for its current configuration, and
print it. This can be useful when attempting to figure out how
to set config in embedded mode. Configure yaws to you liking in
non-embedded mode, run this command and use the output to popu‐
late the embedded mode records.
--load Modules [--id id]
Try to (re)load erlang modules into a running daemon. This is
useful after modifying appmods or modules used by scripts.
--debug-dump [--id id]
Produce a debug dump on stdout. In particular this code lists
what we refer to as suspicious processes. I.e. processes that
might be hanging or processes that are "large" - hardcoded to
40k words.
--ctltrace [--id ID] http | traffic | off
Control the trace capabilities of a running yaws daemon. If the
http or traffic option is given, the daemon will write a log for
debug purposes into the logdir.
--wait-started[=T] [--id ID]
Waits at most 30 seconds for the server to start. Exits with 0
if server is running, 1 otherwise. Typically useful in test
scripts. The default 30 seconds can be modified by appending =T
to the option, where T is the desired number of seconds to wait
for the server to start.
MISC OPTIONS--check YawsFile [IncDirs ....]
Test compile a `.yaws' file. Useful in Makefiles when we want to
ensure that all .yaws files are syntactically correct
--version
output version information and exit
ENVIRONMENT VARIABLES
HOME Is used to determine where we write the temporary files. By
default all tmp files end up in $HOME/.yaws. This includes the
JIT files that are the result of processed .yaws files and also
the so called control file that is used by the daemon to write
the port number to which it is listening for control commands
such as "yaws --status"
Thus HOME is the handle we use in the control commands to find
the control file so that we know where to connect to.
YAWSHOME
Can be used to override the HOME variable. This is useful when
we for example are running yaws under port binding programs such
as authpriv.
It's useful by distros that don't want Yaws to write any files
ever in the HOME directory of root.
AUTHOR
Written by Claes Wikstrom
SEE ALSOyaws.conf(5)erl(1)YAWS(1)
