yaws \- yet another webserver

.B yaws

[\fIOPTIONS\fR]

.PP

Yaws is fast lightweight webserver. It can run as daemon or

in interactive 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.

.TP

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.

.TP

Cygwin inteactive mode (werl)

.TP

Daemon mode. This will start yaws as a daemon.

.TP

This will cause the yaws system to be automatically restarted

in case it should crash. This switch also requires the \fI--daemon\fR

switch to be present.

.TP

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 \fIC\fR restarts in \fIT\fR

seconds instead. To allow infinite restarts, set both \fIC\fR and

\fIT\fR to 0. This switch automatically enables the \fI--heart\fR

switch.

.TP

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.

.TP

Non-debug mode. This is useful for running interactively via the

\FI-i\fR option but without incurring the performance penalties of

debug mode.

.TP

Use a different configuration file than the default. If the configuration

parameter \fIconfig\fR is set, yaws use it as default configuration file. Else,

The default configuration file when running as root is /etc/yaws/yaws.conf. When

running as a non priviliged 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.

.TP

Tells yaws to call \fImodule:start/0\fR at startup. This makes it possible

to startup user specific applications together with yaws.

.TP

Add path to the yaws system search path

.TP

Traffic trace mode. All traffic will be written to a trace file called trace.traffic

in the log directory.

.TP

HTTP trace mode. All HTTP messages will be written to a trace file called trace.http

in the log directory.

.TP

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.

.TP

Sames as --tracetraf --traceout. I.e. trace everything and write to stdout.

.TP

Start Mnesia in directory <dir>

.TP

Start yaws as a distributed erlang node with name <xxx>

using the unqualified hostname as nodename postfix

.TP

By default, yaws starts erlang with \fI+K true\fR. This flag

reverses that.

.TP

Start yaws as a distributed erlang node with name <xxx> using the

fully qualified hostname as nodename postfix

.TP

Use module Mod for erlang distribution. This is typically only used

when we want to run erlang distribution over SSL.

.TP

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 \fI-env NAME O'Keeffe\fR to "erl" from a Bourne-compatible

shell:

.PP

.nf

.ce

--erlarg "-env NAME O\\'Keeffe"

.fi

.TP

This flag sets the id. If we're starting a daemon (or an interactive

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 control 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.

.TP

Set the umask for the daemon to MASK.

.TP

Set the config file encoding (default: latin1).

.PP

The following list of options are are used to control the daemon

from the "outside" while it is running.

.TP

HUP the daemon. This forces the daemon to reread the configuration file.

It also makes

the daemon empty all its internal content caches.

Hence when updating the doc root,

HUPing the daemon is the fastest way to see the content updates.

.TP

Stop the daemon (called id)

.TP

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.

.TP

Query a running yaws daemon for its status, and print it.

.TP

Query a running yaws daemon for its statistics, and print it.

.TP

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 populate the embedded mode records.

.TP

Try to (re)load erlang modules into a running daemon. This is useful

after modifying appmods or modules used by scripts.

.TP

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.

.TP

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.

.TP

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 \fI=T\fR to the option,

where \fIT\fR is the desired number of seconds to wait for the server

to start.

.TP

Test compile a `.yaws' file. Useful in Makefiles when we want to ensure

that all .yaws files are syntactically correct

.TP

output version information and exit

.TP

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.

.TP

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.

Written by Claes Wikstrom

.BR yaws.conf (5)

.BR erl (1)