I am working with Ubuntu 16.04 and I have two shell scripts:
run_roscore.sh : This one fires up a roscore in one terminal.
run_detection_node.sh : This one starts an object detection node in another terminal and should start up once run_roscore.sh has initialized the roscore.
I need both the scripts to execute as soon as the system boots up.
I made both scripts executable and then added the following command to cron:
#reboot /path/to/run_roscore.sh; /path/to/run_detection_node.sh, but it is not running.
I have also tried adding both scripts to the Startup Applications using this command for roscore: sh /path/to/run_roscore.sh and following command for detection node: sh /path/to/run_detection_node.sh. And it still does not work.
How do I get these scripts to run?
EDIT: I used the following command to see the system log for the CRON process: grep CRON /var/log/syslog and got the following output:
CRON[570]: (CRON) info (No MTA installed, discarding output).
So I installed MTA and then systemlog shows:
CRON[597]: (nvidia) CMD (/path/to/run_roscore.sh; /path/to/run_detection_node.sh)
I am still not able to see the output (which is supposed to be a camera stream with detections, as I see it when I run the scripts directly in a terminal). How should I proceed?
Since I got this working eventually, I am gonna answer my own question here.
I did the following steps to get the script running from startup:
Changed the type of the script from shell to bash (extension .bash).
Changed the shebang statement to be #!/bin/bash.
In Startup Applications, give the command bash path/to/script to run the script.
Basically when I changed the shell type from sh to bash, the script starts running as soon as the system boots up.
Note, in case this helps someone: My intention to have run_roscore.bash as a separate script was to run roscore as a background process. One can run it directly from a single script (which is also running the detection node) by having roscore& as a command before the rosnode starts. This command will fire up the master as a background process and leave the same terminal open for following commands to be executed.
If you could install immortal you could use the require option to start in sequence your services, for example, this is could be the run config for /etc/immortal/script1.yml:
cmd: /path/to/script1
log:
file: /var/log/script1.log
wait: 1
require:
- script2
And for /etc/immortal/script2.yml
cmd: /path/to/script2
log:
file: /var/log/script2.log
What this will do it will try to start both scripts on boot time, the first one script1 will wait 1 second before starting and also wait for script2 to be up and running, see more about the wait and require option here: https://immortal.run/post/immortal/
Based on your operating system you will need to configure/setup immortaldir, her is how to do it for Linux: https://immortal.run/post/how-to-install/
Going more deep in the topic of supervisors there are more alternatives here you could find some: https://en.wikipedia.org/wiki/Process_supervision
If you want to make sure that "Roscore" (whatever it is) gets started when your Ubuntu starts up then you should start it as a service (not via cron).
See this question/answer.
Related
I have Debian OS, and I want to start shell script after lightdm is being logged in, how can I do that?
I tried to put
session-setup-script=/path/to/my/script in /etc/lightdm/lightdm.conf
file, but It won't work.
Any advice?
Try invoking your script in an ~/.xsession file.
This file is executed upon X server startup. More info here: https://unix.stackexchange.com/questions/47359/what-is-xsession-for
I was having the same issue and realised that I had set the option at the wrong point in /etc/lightdm/lightdm.conf, a silly mistake.
The seat defaults are documented before the [SeatDefaults] heading and I was placing my setting on the line below the documentation.
so
# session-setup-script = Script to run when starting a user session (runs as root)
session-setup-script=/usr/bin/bla
Looking further down the file I found the heading [SeatDefaults] and below that the setting.
#session-setup-script=
Un-commenting that line and setting the script worked as expected.
I need to run my nodejs script for every second ,Similar to PHP cron jobs. I have tried some nodejs cron libraries like https://github.com/ncb000gt/node-cron but the issue was first run should be manual i:e I have to run the file with cron script for first time manually.
But in php cron jobs, they run by the server so if the apache server running script will automatically start and even if the script return an error for a cycle then script will run again from the beginning from the next cycle
So is there any way to achieve this in nodejs ?
You have two options:
using Node as a daemon, with something like Supervisord to run your node-cron script. This alternative is wasteful on resources such as RAM because Node and Supervisord are running all the time.
using the system's crontab, you can run your script like calling Node on the command line, such as * * * * node /path/to/your/script.js. This alternative is highly efficient but lacks some control, like being able to log the output in case of an error, although you could just pipe the output to a file: node script.js > logfile
I installed the Freeswitch on Ubuntu Image in the Docker, referring to the documentation mentioned here.
When I did the following:
Start FreeSWITCH
First Time
cd /usr/local/freeswitch/bin
./freeswitch
I got to the following screen on my command prompt.
And as the last line says, [WARNING] switch_console.c:1053 We've become an orphan, no more console for us., something is wrong here I believe.
As per the documentation, I was expecting the prompt, like freeswitch#domain> .
Does anyone know what could be the problem? Upon researching this error I landed at the source file many times at different places, for example, one mentioned here
I had the same problem.
If we look in the source code of Freeswitch, we see
if (getppid() == 1) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "We've become an orphan, no more console for us.\n");
break;
}
We see that we had pid == 1, this mean that parent process for freeswitch is init process but we launched it in bash
docker run -it freeswitch_container bash
Problem described here
To solve this you just need to run another bash in running bash, so it will have pid != 1.
I use playframework2.2 and sbt 0.13.1, I can run the sbt and start the server on command line
sbt start
it works ok. but when I run:
nohup sbt start
It run a while and then stop with log error:
(Starting server. Type Ctrl+D to exit logs, the server will remain in background) java.io.IOException: Bad file descriptor
at java.io.FileInputStream.read0(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:210)
at jline.internal.NonBlockingInputStream.read(NonBlockingInputStream.java:248)
at jline.internal.InputStreamReader.read(InputStreamReader.java:261)
at jline.internal.InputStreamReader.read(InputStreamReader.java:198)
at jline.console.ConsoleReader.readCharacter(ConsoleReader.java:2038)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1.play$PlayConsoleInteractionMode$$anonfun$$waitEOF$1(PlayInteractionMode.scala:36)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1$$anonfun$apply$1.apply$mcV$sp(PlayInteractionMode.scala:45)
at play.PlayConsoleInteractionMode$$anonfun$doWithoutEcho$1.apply(PlayInteractionMode.scala:52)
at play.PlayConsoleInteractionMode$$anonfun$doWithoutEcho$1.apply(PlayInteractionMode.scala:49)
at play.PlayConsoleInteractionMode$.withConsoleReader(PlayInteractionMode.scala:31)
at play.PlayConsoleInteractionMode$.doWithoutEcho(PlayInteractionMode.scala:49)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1.apply(PlayInteractionMode.scala:45)
at play.PlayConsoleInteractionMode$$anonfun$waitForKey$1.apply(PlayInteractionMode.scala:34)
at play.PlayConsoleInteractionMode$.withConsoleReader(PlayInteractionMode.scala:31)
at play.PlayConsoleInteractionMode$.waitForKey(PlayInteractionMode.scala:34)
at play.PlayConsoleInteractionMode$.waitForCancel(PlayInteractionMode.scala:55)
at play.PlayRun$$anonfun$24$$anonfun$apply$9.apply(PlayRun.scala:373)
at play.PlayRun$$anonfun$24$$anonfun$apply$9.apply(PlayRun.scala:352)
at scala.util.Either$RightProjection.map(Either.scala:536)
at play.PlayRun$$anonfun$24.apply(PlayRun.scala:352)
at play.PlayRun$$anonfun$24.apply(PlayRun.scala:334)
at sbt.Command$$anonfun$sbt$Command$$apply1$1$$anonfun$apply$6.apply(Command.scala:72)
at sbt.Command$.process(Command.scala:95)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:100)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:100)
at sbt.State$$anon$1.process(State.scala:179)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:100)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:100)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
at sbt.MainLoop$.next(MainLoop.scala:100)
at sbt.MainLoop$.run(MainLoop.scala:93)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:71)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:66)
at sbt.Using.apply(Using.scala:25)
at sbt.MainLoop$.runWithNewLog(MainLoop.scala:66)
at sbt.MainLoop$.runAndClearLast(MainLoop.scala:49)
at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:33)
at sbt.MainLoop$.runLogged(MainLoop.scala:25)
at sbt.StandardMain$.runManaged(Main.scala:57)
at sbt.xMain.run(Main.scala:29)
at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:57)
at xsbt.boot.Launch$.withContextLoader(Launch.scala:77)
at xsbt.boot.Launch$.run(Launch.scala:57)
at xsbt.boot.Launch$$anonfun$explicit$1.apply(Launch.scala:45)
at xsbt.boot.Launch$.launch(Launch.scala:65)
at xsbt.boot.Launch$.apply(Launch.scala:16)
at xsbt.boot.Boot$.runImpl(Boot.scala:32)
at xsbt.boot.Boot$.main(Boot.scala:21)
at xsbt.boot.Boot.main(Boot.scala)
error[0m] [0mjava.io.IOException: Bad file descriptor[0m
error[0m] [0mUse 'last' for the full log.[0m
Any one know which file is Bad file descriptor. And How to solve this problem.
The error happens because standard input get redirected from /dev/null by nohup - you get the same error if you do play start < /dev/null. The sbt process starts the actual server in a separate process, the sets itself up to display logs and wait for you to type Ctrl-D or Ctrl-C. It uses JLine to wait for user input, which attempts to attach to the standard input as a terminal. /dev/null can't be used in this way, so it dies complaining of a bad file descriptor. However, the background server process continues running.
If you want to start Play non-interactively, you need to use the stage task. See Using the stage task in the Play documentation.
There is a linux script that contain a statement used to run a java application.
Script (runServer.sh) is like:
java ServerApp &
Since java application is a server , it keeps running forever until gets stopped. Therefore after running runServer.sh it does not return console automatically and keeps waiting to press return key.
And same problem couses remote script call via Runtime api waiting forever.
proc = rt.exec(runScript);
exitVal = proc.waitFor();
Even When running remote script via ssh say from machine1, crtl+c has to be used to exit from remote script execution.
When I insert following statement into runServer.sh, problem is resolved. But in that case I could not write process id into a file via "echo $? >pid"
exec > "\tmp\outlog.txt" 2>&1
Is there a way of returning console automatically by modifiying linux script.
Change the script to:
nohup java ServerApp &