1PROCSERV(1) procServ Manual PROCSERV(1)
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6 procServ - Process Server with Telnet Console and Log Access
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9 procServ [OPTIONS] port command args...
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13 procServ(1) creates a run time environment for a command (e.g. a soft
14 IOC). It forks a server run as a daemon into the background, which
15 creates a child process running command with all remaining args from
16 the command line. The server provides console access (stdin/stdout) to
17 the child process by offering a telnet connection at the specified
18 port. For security reasons, access is restricted to connections from
19 localhost (127.0.0.1), so that logging into a valid account on the host
20 machine is required.
21 procServ can be configured to write a console log of all in- and output
23 of the child process into a file using the -L (--logfile) option. To
24 facilitate running under a central console access management (like
25 conserver), the -l (--logport) option creates an additional telnet
26 port, which is by default public (i.e. not restricted to localhost),
27 and provides read-only log access to the child´s console. The -r
28 (--restrict) option restricts the log port to localhost, similar to the
29 access port.
30 Both access and log ports allow multiple connections, which are handled
32 transparently: all input from access connections is forwarded to the
33 child process, all output from the child is forwarded to all access and
34 log connections (and written to the log file). All diagnostic messages
35 from the server process start with "@@@ " to be clearly distinguished
36 from child process messages. A name specified by the -n (--name) option
37 will replace the command string in many messages for increased
38 readability.
39 The server will by default automatically respawn a child process when
41 it dies. To avoid spinning, a minimum time between child process
42 restarts is honoured (default: 15 seconds, can be changed using the
43 --holdoff option). This behaviour can be toggled online using the
44 toggle command ^T, the default may be changed using the --noautorestart
45 option. You can restart a running child manually by sending a signal to
46 the child process using the kill command ^X. With the child process
47 being shut down, the server accepts two commands: ^R to restart the
48 child and ^Q to quit the server. The -w (--wait) option starts the
49 server in this shut down mode, waiting for the telnet connection to
50 issue a manual start command to create the child.
51 To block input characters that are potentially dangerous to the child
53 (e.g. ^D and ^C on soft IOCs), the -i (--ignore) option can be used to
54 specify characters that are silently ignored when coming from a console
55 access port.
56 To facilitate being started and stopped as a standard system service,
58 the -p (--pidfile) option tells the server to create a standard PID
59 file containing the PID of the server process.
60 The -d (--debug) option runs the server in debug mode: the daemon
62 process stays in the foreground, printing all regular log content plus
63 additional debug messages to stdout.
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67 --allow
68 Allow control connections from anywhere. (Default: restrict control
69 access to localhost.) Creates a serious security hole, as telnet
70 clients from anywhere can connect to the child´s stdin/stdout and
71 execute arbitrary commands on the host, if the child permits. Needs
72 to be enabled at compile-time (see Makefile). Please do not enable
73 and use this option unless you exactly know why and what you are
74 doing.
75 --autorestartcmd=char
77 Toggle auto restart flag when char is sent on an access connection.
78 Use ^ to specify a control character, "" to disable. Default is ^T.
79 --coresize=size
81 Set the maximum size of core file. See getrlimit(2) documentation
82 for details. Setting size to 0 will keep child from creating core
83 files.
84 -c, --chdir=dir
86 Change directory to dir before starting child. This is done each
87 time the child is started to make sure symbolic links are resolved
88 on child restart.
89 -d, --debug
91 Enter debug mode. Debug mode will keep the server process in the
92 foreground and enables diagnostic messages that will be sent to the
93 controlling terminal.
94 -h, --help
96 Print help message.
97 --holdoff=n
99 Wait at least n seconds between child restart attempts. Default is
100 15 seconds.
101 -i, --ignore=chars
103 Ignore all characters in chars on access connections. This can be
104 used to shield the child process from input characters that are
105 potentially dangerous, e.g. ^D and ^C characters that would shut
106 down a soft IOC. Use ^ to specify control characters, ^^ to specify
107 a single ^ character.
108 -k, --killcmd=char
110 Kill the child process (child will be restarted automatically by
111 default) when char is sent on an access connection. Use ^ to
112 specify a control character, "" for no kill command. Default is ^X.
113 --killsig=signal
115 Kill the child using signal when receiving the kill command.
116 Default is 9 (SIGKILL).
117 -l, --logport=port
119 Provide read-only access to the child´s console on port. By default
120 all hosts can connect to port, use the -r (--restrict) option to
121 restrict access to localhost.
122 -L, --logfile=file
124 Write a console log of all in- and output to file.
125 -n, --name=title
127 In all server messages, use title instead of the full command line
128 to increase readability.
129 --noautorestart
131 Do not automatically restart child process on exit.
132 -p, --pidfile=file
134 Write the PID of the server process into file to facilitate
135 integration into regular system service administration mechanisms.
136 --timefmt=fmt
138 Set the format string used to print time stamps to fmt. Default is
139 "%c". (See strftime(3) documentation for details.)
140 -q, --quiet
142 Do not write informational output (server). Avoids cluttering the
143 screen when run as part of a system script.
144 --restrict
146 Restrict log connections to localhost.
147 -V, --version
149 Print program version.
150 -w, --wait
152 Do not start the child. Instead, wait for a telnet connection and a
153 manual start command.
154
156 To start a soft IOC using procServ, change the directory into the IOC´s
157 boot directory. A typical command line would be
158 procServ -n "My SoftIOC" -i ^D^C 20000 ./st.cmd
161 To connect to the IOC, log into the soft IOC´s host and connect to port
162 20000 using
163 telnet localhost 20000
166 To connect from a remote machine, ssh to a user account on procservhost
167 and connect to port 20000 using
168 ssh -t user@procservhost telnet localhost 20000
171 You will be connected to the soft IOCs console and receive an
172 informative welcome message. All output from the procServ server will
173 start with "@@@ " to allow telling it apart from messages that your IOC
174 sends.
175 > telnet localhost 20000
178 Trying 127.0.0.1...
179 Connected to localhost.
180 Escape character is ´^]´.
181 @@@ Welcome to the procServ process server (procServ Version 2.1.0)
182 @@@ Use ^X to kill the child, auto restart is ON, use ^T to toggle auto restart
183 @@@ procServ server PID: 21413
184 @@@ Startup directory: /projects/ctl/lange/epics/ioc/test314/iocBoot/iocexample
185 @@@ Child "My SoftIOC" started as: ./st.cmd
186 @@@ Child "My SoftIOC" PID: 21414
187 @@@ procServ server started at: Fri Apr 25 16:43:00 2008
188 @@@ Child "My SoftIOC" started at: Fri Apr 25 16:43:00 2008
189 @@@ 0 user(s) and 0 logger(s) connected (plus you)
190 Type the kill command character ^X to reboot the soft IOC and get
191 server messages about this action.
192 Type the telnet escape character ^] to get back to a telnet prompt and
194 quit to exit telnet (and ssh when you were connecting remotely).
195 While procServ was originally intended to be an environment to run soft
197 IOCs, any process might be started as child. It provides an environment
198 for any program that requires access to its console and should be run
199 in the background as a daemon. By writing a file log directly or
200 through a console access and logging facility (such as conserver), the
201 log of such a program´s output can be used to correlate its messages to
202 other events. E.g., in an EPICS environment, running casw (the beacon
203 anomaly watcher) can provide useful log output to analyse and track
204 down network issues (name resolution broadcast storms).
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208 PROCSERV_PID
209 This sets the file name to write the PID of the server process
210 into. (See -p option.)
211 PROCSERV_DEBUG
213 If set, procServ starts in debug mode. (See -d option.)
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216 None so far.
217
220 Report bugs on the procServ Trac at
221 http://sourceforge.net/apps/trac/procserv/ or to the authors.
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225 Written by David H. Thompson <thompsondh@ornl.gov> and Ralph Lange
226 <Ralph.Lange@bessy.de>.
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230 SourceForge project: http://sourceforge.net/projects/procserv/
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234 All copyrights reserved. Free use of this software is granted under the
235 terms of the GNU General Public License (GPLv3).
236
239 1. thompsondh@ornl.gov
240 mailto:thompsondh@ornl.gov
241 2. Ralph.Lange@bessy.de
243 mailto:Ralph.Lange@bessy.de
244procServ 2.5.0a2 03/23/2010 PROCSERV(1)