Provided by: procserv_2.7.0-1build2_amd64 
NAME
procServ - Process Server with Telnet Console and Log Access
SYNOPSIS
procServ [OPTIONS] -P endpoint... command args...
procServ [OPTIONS] endpoint command args...
DESCRIPTION
procServ(1) creates a run time environment for a command (e.g. a soft IOC). It forks a
server run as a daemon into the background, which creates a child process running command
with all remaining args from the command line. The server provides control access
(stdin/stdout) to the child process console by offering a telnet connection at the
specified endpoint(s).
An endpoint can either be a TCP server socket (specified by the port number) or a UNIX
domain socket (where available). See ENDPOINT SPECIFICATION below for details. For
security reasons, control access is restricted to connections from localhost (127.0.0.1),
so that a prior login in to the host machine is required. (See --allow option.)
The first variant allows multiple endpoint declarations and treats all non-option
arguments as the command line for the child process. The second variant (provided for
backward compatibility) declares one endpoint with its specification taken from the first
non-option argument.
procServ can be configured to write a console log of all in- and output of the child
process into a file using the -L (--logfile) option. Sending the signal SIGHUP to the
server will make it reopen the log file.
To facilitate running under a central console access management (like conserver), the -l
(--logport) option creates an additional endpoint, which is by default public (i.e. TCP
access is not restricted to connections from localhost), and provides read-only (log)
access to the child’s console. The -r (--restrict) option restricts both control and log
access to connections from localhost.
Both control and log endpoints allow multiple connections, which are handled
transparently: all input from control connections is forwarded to the child process, all
output from the child is forwarded to all control and log connections (and written to the
log file). All diagnostic messages from the procServ server process start with "@@@" to be
clearly distinguishable from child process messages. A name specified by the -n (--name)
option will replace the command string in many messages for increased readability.
The server will by default automatically respawn the child process when it dies. To avoid
spinning, a minimum time between child process restarts is honored (default: 15 seconds,
can be changed using the --holdoff option). This behavior can be toggled online using the
toggle command ^T, the default may be changed using the --noautorestart option. You can
restart a running child manually by sending a signal to the child process using the kill
command ^X. With the child process being shut down, the server accepts two commands: ^R or
^X to restart the child, and ^Q to quit the server. The -w (--wait) option starts the
server in this shut down mode, waiting for a control connection to issue a manual start
command to spawn the child.
Any connection (control or log) can be disconnected using the client’s disconnect
sequence. Control connections can also be disconnected by sending the logout command
character that can be specified using the -x (--logoutcmd) option.
To block input characters that are potentially dangerous to the child (e.g. ^D and ^C on
soft IOCs), the -i (--ignore) option can be used to specify characters that are silently
ignored when coming from a control connection.
To facilitate being started and stopped as a standard system service, the -p (--pidfile)
option tells the server to create a PID file containing the PID of the server process. The
-I (--info-file) option writes a file listing the server PID and a list of all endpoints.
The -d (--debug) option runs the server in debug mode: the daemon process stays in the
foreground, printing all regular log content plus additional debug messages to stdout.
ENDPOINT SPECIFICATION
Both control and log endpoints may be bound to either TCP or UNIX sockets (where
supported). Allowed endpoint specifications are:
<port>
Bind to either 0.0.0.0:<port> (any) or 127.0.0.1:<port> (localhost) depending on the
type of endpoint and the setting of -r (--restrict) and --allow options.
<ifaceaddr>:<port>
Bind to the specified interface address and <port>. The interface IP address
<ifaceaddr> must be given in numeric form. Uses 127.0.0.1 (localhost) for security
reasons unless the --allow option is also used.
unix:</path/to/socket>
Bind to a named unix domain socket that will be created at the specified absolute or
relative path. The server process must have permission to create files in the
enclosing directory. The socket file will be owned by the uid and primary gid of the
procServ server process with permissions 0666 (equivalent to a TCP socket bound to
localhost).
unix:<user>:<group>:<perm>:</path/to/socket>
Bind to a named unix domain socket that will be created at the specified absolute or
relative path. The server process must have permission to create files in the
enclosing directory. The socket file will be owned by the specified <user> and <group>
with <perm> permissions. Any of <user>, <group>, and/or <perm> may be omitted. E.g.
"-P unix::grp:0660:/run/procServ/foo/control" will create the named socket with 0660
permissions and allow the "grp" group connect to it. This requires that procServ be
run as root or a member of "grp".
unix:@</path/to/socket>
Bind to an abstract unix domain socket (Linux specific). Abstract sockets do not exist
on the filesystem, and have no permissions checks. They are functionally similar to a
TCP socket bound to localhost, but identified with a name string instead of a port
number.
OPTIONS
--allow
Allow TCP control connections from anywhere. (Default: restrict control access to
connections from localhost.) Creates a serious security hole, as telnet clients from
anywhere can connect to the child’s stdin/stdout and might execute arbitrary commands
on the host if the child permits. Needs to be enabled at compile-time (see Makefile).
Please do not enable and use this option unless you exactly know why and what you are
doing.
--autorestartcmd=char
Toggle auto restart flag when char is sent on a control connection. Use ^ to specify a
control character, "" to disable. Default is ^T.
--coresize=size
Set the maximum size of core file. See getrlimit(2) documentation for details. Setting
size to 0 will keep child from creating core files.
-c, --chdir=dir
Change directory to dir before starting the child. This is done each time the child is
started to make sure symbolic links are properly resolved on child restart.
-d, --debug
Enter debug mode. Debug mode will keep the server process in the foreground and
enables diagnostic messages that will be sent to the controlling terminal.
-e, --exec=file
Run file as executable for child. Default is command.
-f, --foreground
Keep the server process in the foreground and connected to the controlling terminal.
-h, --help
Print help message.
--holdoff=n
Wait at least n seconds between child restart attempts. (Default is 15 seconds.)
-i, --ignore=chars
Ignore all characters in chars on control connections. This can be used to shield the
child process from input characters that are potentially dangerous, e.g. ^D and ^C
characters that would shut down a soft IOC. Use ^ to specify control characters, ^^ to
specify a single ^ character.
*-I, --info-file <file>
Write instance information to this file.
-k, --killcmd=char
Kill the child process (child will be restarted automatically by default) when char is
sent on a control connection. Use ^ to specify a control character, "" for no kill
command. Default is ^X.
--killsig=signal
Kill the child using signal when receiving the kill command. Default is 9 (SIGKILL).
-l, --logport=endpoint
Provide read-only log access to the child’s console on endpoint. See ENDPOINT
SPECIFICATION above. By default, TCP log endpoints allow connections from anywhere.
Use the -r (--restrict) option to restrict TCP access to local connections.
-L, --logfile=file
Write a console log of all in and output to file. - selects stdout.
--logstamp[=fmt]
Prefix lines in logs with a time stamp, setting the time stamp format string to fmt.
Default is "[<timefmt>] ". (See --timefmt option.)
-n, --name=title
In all server messages, use title instead of the full command line to increase
readability.
--noautorestart
Do not automatically restart child process on exit.
-P, --port=endpoint
Provide control access to the child’s console on endpoint. See ENDPOINT SPECIFICATION
above. By default, TCP control endpoints are restricted to local connections. Use the
--allow option to allow TCP access from anywhere.
-p, --pidfile=file
Write the PID of the server process into file.
--timefmt=fmt
Set the format string used to print time stamps to fmt. Default is "%c". (See
strftime(3) documentation for details.)
-q, --quiet
Do not write informational output (server). Avoids cluttering the screen when run as
part of a system script.
--restrict
Restrict TCP access (control and log) to connections from localhost.
-V, --version
Print program version.
-w, --wait
Do not start the child immediately. Instead, wait for a control connection and a
manual start command.
-x, --logoutcmd=char
Log out (close client connection) when char is sent on an control connection. Use ^ to
specify a control character. Default is empty.
USAGE
To start a soft IOC using procServ, change the directory into the IOC’s boot directory. A
typical command line would be
procServ -n "My SoftIOC" -i ^D^C 20000 ./st.cmd
To connect to the IOC, log into the soft IOC’s host and connect to port 20000 using
telnet localhost 20000
To connect from a remote machine, ssh to a user account on procservhost and connect to
port 20000 using
ssh -t user@procservhost telnet localhost 20000
You will be connected to the soft IOCs console and receive an informative welcome message.
All output from the procServ server will start with "@@@" to allow telling it apart from
messages that your IOC sends.
> telnet localhost 20000
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
@@@ Welcome to the procServ process server (procServ Version 2.1.0)
@@@ Use ^X to kill the child, auto restart is ON, use ^T to toggle auto restart
@@@ procServ server PID: 21413
@@@ Startup directory: /projects/ctl/lange/epics/ioc/test314/iocBoot/iocexample
@@@ Child "My SoftIOC" started as: ./st.cmd
@@@ Child "My SoftIOC" PID: 21414
@@@ procServ server started at: Fri Apr 25 16:43:00 2008
@@@ Child "My SoftIOC" started at: Fri Apr 25 16:43:00 2008
@@@ 0 user(s) and 0 logger(s) connected (plus you)
Type the kill command character ^X to reboot the soft IOC and get server messages about
this action.
Type the telnet escape character ^] to get back to a telnet prompt then "quit" to exit
telnet (and ssh when you were connecting remotely).
Though procServ was originally intended to be an environment to run soft IOCs, an
arbitrary process might be started as child. It provides an environment for any program
that requires access to its console, while running in the background as a daemon, and
keeping a log by writing a file or through a console access and logging facility (such as
conserver).
ENVIRONMENT VARIABLES
PROCSERV_PID
Sets the file name to write the PID of the server process into. (See -p option.)
PROCSERV_DEBUG
If set, procServ starts in debug mode. (See -d option.)
KNOWN PROBLEMS
None so far.
REPORTING BUGS
Please report bugs using the issue tracker at
https://github.com/ralphlange/procServ/issues.
AUTHORS
Originally written by David H. Thompson (ORNL). Current author: Ralph Lange
<ralph.lange@gmx.de>.
RESOURCES
GitHub project: https://github.com/ralphlange/procServ
COPYING
All copyrights reserved. Free use of this software is granted under the terms of the GNU
General Public License (GPLv3).