How to prevent second script to run after first succeeded in BASH - linux

I did a script in bash, but it geets in some sort of a loop. My script is like a reverse operation with an systemctl service and it's running like this :
if systemctl status service | grep -q "Active: inactive"; then
read -r -p "Service is inactive do you want to start it? : [y/N] : " response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]
then
systemctl start `service` && echo "Service is active"
else
echo "Service stays inactive"
fi
fi
if systemctl status service | grep -q 'Active: active'; then
read -r -p "Service is active, do you want to stop it? [y/N] : " response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]
then
systemctl stop service && echo "Service is inactive"
else
echo "Service stays active"
fi
fi
The problem is when it reach the first part and I want to start it, it jumps to the second part when it asks me if I want to stop it, is there any way to prevent bash doing this and stop it?

Use an else block:
toggle_service() {
local response service=$1
if systemctl is-active "$service"; then
read -r -p "Service is inactive do you want to start it? : [y/N] : " response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]; then
systemctl start "$service" && echo "Service is active" >&2
else
echo "Service stays inactive"
fi
else
read -r -p "Service is active, do you want to stop it? [y/N] : " response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]; then
systemctl stop "$service" && echo "Service is inactive" >&2
else
echo "Service stays active" >&2
fi
fi
}
...or, a DRYer version:
toggle_service() {
local action state_name response service=$1
if systemctl is-active "$service"; then
state_name=active; action=stop
else
state_name=inactive; action=start
fi
read -r -p "Service is ${state_name}, do you want to ${action} it?" response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]; then
systemctl "$action" "$service" && echo "Action complete: ${action} ${service}" >&2
else
echo "${service} remains ${state_name}" >&2
fi
}
Either one can be invoked with:
toggle_service sshd

Related

Bash: Continuously check processes running or not with some parameters

I want to create script that will check continuously process status running or not. If process will not run, script should catch it and restart it in a seconds. How can I run continuously this script on the system and how should I change the script via ---> Important points: it should take as parameters these: 1-seconds to wait between attempts to restart service, 2- number of attempts and 3- generate logs of events. Nginx is a example for the process. It can be replaceable.
#!/bin/bash
SERVICE="nginx"
if pgrep -x "$SERVICE" >/dev/null
then
echo "$SERVICE is running"
else
echo "$SERVICE stopped"
# start nginx if stopped
echo "$SERVICE starting"
systemctl start $SERVICE
fi
You can try something like this:
#!/bin/bash
service="nginx"
seconds=2
retries=3
until (( retries-- == 0 ))
do
property=$(systemctl show --property MainPID "$service")
if [[ $property == MainPID=0 ]]
then
echo "$service stopped"
echo "$service starting"
systemctl start "$service" >& /dev/null
else
echo "$service is running"
exit
fi
sleep "$seconds"
done
echo "$service is broken"

systemd service works different then running the .sh file from user shell trying run a VNC startup script with noVNC

I want to run a .sh file with a systemd service. Let's explain it a little bit. If I go to cd /home/ubuntu I can run ./vnc_startup.sh. This file creates a VNC connection and starts noVNC. Then I go to the browser open the address and login. I can run every command like as example rosrun rviz rviz because I have installed ROS.
If I use this service, it will not work:
cat /etc/systemd/system/novnc.service
[Unit]
After=NetworkManager.service time-sync.target
[Service]
Type=forking
User=ubuntu
Group=ubuntu
WorkingDirectory=/home/ubuntu
TimeoutStartSec=infinity
TimeoutStopSec=infinity
ExecStartPre=/bin/rm -f /home/ubuntu/no_vnc_startup.log
ExecStartPre=/bin/rm -f /home/ubuntu/vnc_startup.log
ExecStartPre=/bin/rm -f /home/ubuntu/wm.log
ExecStartPre=/bin/rm -f /home/ubuntu/wm_startup.log
ExecStart=/bin/bash -c "source /etc/environment; /home/ubuntu/vnc_startup.sh"
ExecStopPost=/bin/rm -f /home/ubuntu/no_vnc_startup.log
ExecStopPost=/bin/rm -f /home/ubuntu/vnc_startup.log
ExecStopPost=/bin/rm -f /home/ubuntu/wm.log
ExecStopPost=/bin/rm -f /home/ubuntu/wm_startup.log
[Install]
WantedBy=multi-user.target
I also tried it with systemctl --user start novnc.service and put the file inside /usr/lib/systemd/user instead of sudo systemctl start novnc.service and /etc/systemd/system/novnc.service.
Following workaround will work in the noVNC environment: I can open a Terminal. I can see ubuntu#hostname:~$. So it seems to be the right user and I am in the right working directory. Before running as example rosrun rviz rviz I have to run sudo su ubuntu. And then it works. If I had run ./vnc_startup.sh instead of running this script with systemd it works directly without the workaround with sudo su ubuntu.
Hard to explain. I hope you can understand me.
systemctl --user show-environment
HOME=/home/ubuntu
LANG=de_DE
LOGNAME=ubuntu
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin
SHELL=/bin/bash
USER=ubuntu
XDG_RUNTIME_DIR=/run/user/1001
The command printenv makes clear that maybe the DISPLAY=:0 is missing, so I tried it with adding
export DISPLAY=:0
xset q
And I also added Environment=XAUTHORITY=/home/ubuntu/.Xauthority:
[Unit]
After=NetworkManager.service time-sync.target
[Service]
Type=forking
User=ubuntu
Group=ubuntu
WorkingDirectory=/home/ubuntu
Environment=XAUTHORITY=/home/ubuntu/.Xauthority
TimeoutStartSec=infinity
TimeoutStopSec=infinity
ExecStartPre=/bin/rm -f /home/ubuntu/no_vnc_startup.log
ExecStartPre=/bin/rm -f /home/ubuntu/vnc_startup.log
ExecStartPre=/bin/rm -f /home/ubuntu/wm.log
ExecStartPre=/bin/rm -f /home/ubuntu/wm_startup.log
ExecStart=/bin/bash -c "source /etc/environment; export DISPLAY=:0; xset q; /home/ubuntu/vnc_startup.sh"
ExecStopPost=/bin/rm -f /home/ubuntu/no_vnc_startup.log
ExecStopPost=/bin/rm -f /home/ubuntu/vnc_startup.log
ExecStopPost=/bin/rm -f /home/ubuntu/wm.log
ExecStopPost=/bin/rm -f /home/ubuntu/wm_startup.log
[Install]
WantedBy=multi-user.target
Here my log files:
cat no_vnc_startup.log
New 'shlServer01:1 (ubuntu)' desktop is shlServer01:1
Starting applications specified in /home/ubuntu/.vnc/xstartup
Log file is /home/ubuntu/.vnc/shlServer01:1.log
r settings:
- Listen on :6901
- Flash security policy server
- Web server. Web root: /home/ubuntu/noVNC
- No SSL/TLS support (no cert file)
- proxying from :6901 to localhost:5901
Navigate to this URL:
http://shlServer01:6901/vnc.html?host=shlServer01&port=6901
Press Ctrl-C to exit
192.168.0.6 - - [15/Dec/2021 15:16:56] 192.168.0.6: Plain non-SSL (ws://) WebSocket connection
192.168.0.6 - - [15/Dec/2021 15:16:56] 192.168.0.6: Version hybi-13, base64: 'False'
192.168.0.6 - - [15/Dec/2021 15:16:56] 192.168.0.6: Path: '/websockify'
192.168.0.6 - - [15/Dec/2021 15:16:56] connecting to: localhost:5901
cat vnc_startup.log
Killing Xvnc process ID 63164
Xvnc process ID 63164 already killed
cat wm.log
/usr/bin/startxfce4: X server already running on display :0
xfce4-session: Cannot open display: .
▒xfce4-session --help▒ eingeben, um mehr ▒ber die Verwendung zu erfahren.
cat wm_startup.log
------------------ startup of Xfce4 window manager ------------------
No protocol specified
xset: unable to open display ":0"
No protocol specified
xset: unable to open display ":0"
No protocol specified
xset: unable to open display ":0"
No protocol specified
xrdb: Resource temporarily unavailable
xrdb: Can't open display ':0'
No protocol specified
No protocol specified
/usr/bin/startxfce4: X server already running on display :0
xfce4-session: Cannot open display: .
▒xfce4-session --help▒ eingeben, um mehr ▒ber die Verwendung zu erfahren.
What surprises me is that this is not the error. The error messages also come when I start the script from the terminal and then it works.
The vnc_startup.sh looks like following:
#!/bin/bash
### every exit != 0 fails the script
set -e
## print out help
help (){
echo "
OPTIONS:
-w, --wait (default) keeps the UI and the vncserver up until SIGINT or SIGTERM will received
-s, --skip skip the vnc startup and just execute the assigned command.
example: docker run consol/centos-xfce-vnc --skip bash
-d, --debug enables more detailed startup output
e.g. 'docker run consol/centos-xfce-vnc --debug bash'
-h, --help print out this help
Fore more information see: https://github.com/ConSol/docker-headless-vnc-container
"
}
if [[ $1 =~ -h|--help ]]; then
help
exit 0
fi
# should also source /home/ubuntu/generate_container_user
source /home/ubuntu/.bashrc
# add `--skip` to startup args, to skip the VNC startup procedure
if [[ $1 =~ -s|--skip ]]; then
echo -e "\n\n------------------ SKIP VNC STARTUP -----------------"
echo -e "\n\n------------------ EXECUTE COMMAND ------------------"
echo "Executing command: '${#:2}'"
exec "${#:2}"
fi
if [[ $1 =~ -d|--debug ]]; then
echo -e "\n\n------------------ DEBUG VNC STARTUP -----------------"
export DEBUG=true
fi
## correct forwarding of shutdown signal
cleanup () {
kill -s SIGTERM $!
exit 0
}
trap cleanup SIGINT SIGTERM
## write correct window size to chrome properties
/home/ubuntu/chrome-init.sh
## resolve_vnc_connection
VNC_IP=$(hostname -i)
## change vnc password
echo -e "\n------------------ change VNC password ------------------"
# first entry is control, second is view (if only one is valid for both)
mkdir -p "/home/ubuntu/.vnc"
PASSWD_PATH="/home/ubuntu/.vnc/passwd"
if [[ -f $PASSWD_PATH ]]; then
echo -e "\n--------- purging existing VNC password settings ---------"
rm -f $PASSWD_PATH
fi
if [[ $VNC_VIEW_ONLY == "true" ]]; then
echo "start VNC server in VIEW ONLY mode!"
#create random pw to prevent access
echo $(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 20) | vncpasswd -f > $PASSWD_PATH
fi
echo "ubuntu" | vncpasswd -f >> $PASSWD_PATH
chmod 600 $PASSWD_PATH
## start vncserver and noVNC webclient
echo -e "\n------------------ start noVNC ----------------------------"
if [[ $DEBUG == true ]]; then echo "/home/ubuntu/noVNC/utils/launch.sh --vnc localhost:5901 --listen 6901"; fi
/home/ubuntu/noVNC/utils/launch.sh --vnc localhost:5901 --listen 6901 &> /home/ubuntu/no_vnc_startup.log &
PID_SUB=$!
echo -e "\n------------------ start VNC server ------------------------"
echo "remove old vnc locks to be a reattachable container"
vncserver -kill :1 &> /home/ubuntu/vnc_startup.log \
|| rm -rfv /tmp/.X*-lock /tmp/.X11-unix &> /home/ubuntu/vnc_startup.log \
|| echo "no locks present"
echo -e "start vncserver with param: VNC_COL_DEPTH=24, VNC_RESOLUTION=1280x1024\n..."
if [[ $DEBUG == true ]]; then echo "vncserver :1 -depth 24 -geometry 1280x1024"; fi
vncserver :1 -depth 24 -geometry 1280x1024 &> /home/ubuntu/no_vnc_startup.log
echo -e "start window manager\n..."
/home/ubuntu/wm_startup.sh &> /home/ubuntu/wm_startup.log
## log connect options
echo -e "\n\n------------------ VNC environment started ------------------"
echo -e "\nVNCSERVER started on DISPLAY= :1 \n\t=> connect via VNC viewer with $VNC_IP:5901"
echo -e "\nnoVNC HTML client started:\n\t=> connect via http://$VNC_IP:6901/?password=...\n"
if [[ $DEBUG == true ]] || [[ $1 =~ -t|--tail-log ]]; then
echo -e "\n------------------ /home/ubuntu/.vnc/*:1.log ------------------"
# if option `-t` or `--tail-log` block the execution and tail the VNC log
tail -f /home/ubuntu/*.log /home/ubuntu/.vnc/*:1.log
fi
if [ -z "$1" ] || [[ $1 =~ -w|--wait ]]; then
wait $PID_SUB
else
# unknown option ==> call command
echo -e "\n\n------------------ EXECUTE COMMAND ------------------"
echo "Executing command: '$#'"
exec "$#"
fi
The wm_startup.sh looks like this:
#!/usr/bin/env bash
### every exit != 0 fails the script
set -e
echo -e "\n------------------ startup of Xfce4 window manager ------------------"
### disable screensaver and power management
xset -dpms &
xset s noblank &
xset s off &
/usr/bin/startxfce4 --replace > /home/ubuntu/wm.log &
sleep 1
cat /home/ubuntu/wm.log
And it should not be important but the launch.sh file fom noVNC looks like this:
#!/usr/bin/env bash
# Copyright 2016 Joel Martin
# Copyright 2016 Solly Ross
# Licensed under MPL 2.0 or any later version (see LICENSE.txt)
usage() {
if [ "$*" ]; then
echo "$*"
echo
fi
echo "Usage: ${NAME} [--listen PORT] [--vnc VNC_HOST:PORT] [--cert CERT] [--ssl-only]"
echo
echo "Starts the WebSockets proxy and a mini-webserver and "
echo "provides a cut-and-paste URL to go to."
echo
echo " --listen PORT Port for proxy/webserver to listen on"
echo " Default: 6080"
echo " --vnc VNC_HOST:PORT VNC server host:port proxy target"
echo " Default: localhost:5900"
echo " --cert CERT Path to combined cert/key file"
echo " Default: self.pem"
echo " --web WEB Path to web files (e.g. vnc.html)"
echo " Default: ./"
echo " --ssl-only Disable non-https connections."
echo " "
exit 2
}
NAME="$(basename $0)"
REAL_NAME="$(readlink -f $0)"
HERE="$(cd "$(dirname "$REAL_NAME")" && pwd)"
PORT="6080"
VNC_DEST="localhost:5900"
CERT=""
WEB=""
proxy_pid=""
SSLONLY=""
die() {
echo "$*"
exit 1
}
cleanup() {
trap - TERM QUIT INT EXIT
trap "true" CHLD # Ignore cleanup messages
echo
if [ -n "${proxy_pid}" ]; then
echo "Terminating WebSockets proxy (${proxy_pid})"
kill ${proxy_pid}
fi
}
# Process Arguments
# Arguments that only apply to chrooter itself
while [ "$*" ]; do
param=$1; shift; OPTARG=$1
case $param in
--listen) PORT="${OPTARG}"; shift ;;
--vnc) VNC_DEST="${OPTARG}"; shift ;;
--cert) CERT="${OPTARG}"; shift ;;
--web) WEB="${OPTARG}"; shift ;;
--ssl-only) SSLONLY="--ssl-only" ;;
-h|--help) usage ;;
-*) usage "Unknown chrooter option: ${param}" ;;
*) break ;;
esac
done
# Sanity checks
which netstat >/dev/null 2>&1 \
|| die "Must have netstat installed"
netstat -ltn | grep -qs ":${PORT} .*LISTEN" \
&& die "Port ${PORT} in use. Try --listen PORT"
trap "cleanup" TERM QUIT INT EXIT
# Find vnc.html
if [ -n "${WEB}" ]; then
if [ ! -e "${WEB}/vnc.html" ]; then
die "Could not find ${WEB}/vnc.html"
fi
elif [ -e "$(pwd)/vnc.html" ]; then
WEB=$(pwd)
elif [ -e "${HERE}/../vnc.html" ]; then
WEB=${HERE}/../
elif [ -e "${HERE}/vnc.html" ]; then
WEB=${HERE}
elif [ -e "${HERE}/../share/novnc/vnc.html" ]; then
WEB=${HERE}/../share/novnc/
else
die "Could not find vnc.html"
fi
# Find self.pem
if [ -n "${CERT}" ]; then
if [ ! -e "${CERT}" ]; then
die "Could not find ${CERT}"
fi
elif [ -e "$(pwd)/self.pem" ]; then
CERT="$(pwd)/self.pem"
elif [ -e "${HERE}/../self.pem" ]; then
CERT="${HERE}/../self.pem"
elif [ -e "${HERE}/self.pem" ]; then
CERT="${HERE}/self.pem"
else
echo "Warning: could not find self.pem"
fi
# try to find websockify (prefer local, try global, then download local)
if [[ -e ${HERE}/websockify ]]; then
WEBSOCKIFY=${HERE}/websockify/run
if [[ ! -x $WEBSOCKIFY ]]; then
echo "The path ${HERE}/websockify exists, but $WEBSOCKIFY either does not exist or is not executable."
echo "If you intended to use an installed websockify package, please remove ${HERE}/websockify."
exit 1
fi
echo "Using local websockify at $WEBSOCKIFY"
else
WEBSOCKIFY=$(which websockify 2>/dev/null)
if [[ $? -ne 0 ]]; then
echo "No installed websockify, attempting to clone websockify..."
WEBSOCKIFY=${HERE}/websockify/run
git clone https://github.com/novnc/websockify ${HERE}/websockify
if [[ ! -e $WEBSOCKIFY ]]; then
echo "Unable to locate ${HERE}/websockify/run after downloading"
exit 1
fi
echo "Using local websockify at $WEBSOCKIFY"
else
echo "Using installed websockify at $WEBSOCKIFY"
fi
fi
echo "Starting webserver and WebSockets proxy on port ${PORT}"
#${HERE}/websockify --web ${WEB} ${CERT:+--cert ${CERT}} ${PORT} ${VNC_DEST} &
${WEBSOCKIFY} ${SSLONLY} --web ${WEB} ${CERT:+--cert ${CERT}} ${PORT} ${VNC_DEST} &
proxy_pid="$!"
sleep 1
if ! ps -p ${proxy_pid} >/dev/null; then
proxy_pid=
echo "Failed to start WebSockets proxy"
exit 1
fi
echo -e "\n\nNavigate to this URL:\n"
if [ "x$SSLONLY" == "x" ]; then
echo -e " http://$(hostname):${PORT}/vnc.html?host=$(hostname)&port=${PORT}\n"
else
echo -e " https://$(hostname):${PORT}/vnc.html?host=$(hostname)&port=${PORT}\n"
fi
echo -e "Press Ctrl-C to exit\n\n"
wait ${proxy_pid}
Suggesting to simply your /etc/systemd/system/novnc.service service unit with a single script for ExecStart command and a single script for ExecStop
/etc/systemd/system/novnc.service
[Unit]
After=NetworkManager.service time-sync.target
[Service]
Type=forking
User=ubuntu
Group=ubuntu
WorkingDirectory=/home/ubuntu
Environment=XAUTHORITY=/home/ubuntu/.Xauthority
TimeoutStartSec=infinity
TimeoutStopSec=infinity
ExecStart=/bin/bash -c "/home/ubuntu/servic_vnc_startup.sh"
ExecStop=/bin/bash -c "/home/ubuntu/servic_vnc_shutdown.sh"
[Install]
WantedBy=multi-user.target
/home/ubuntu/servic_vnc_startup.sh
#!\bin\bash
source /home/ubuntu/.bash_profile
source /etc/environment
export DISPLAY=:0
xset q;
rm -f /home/ubuntu/{no_vnc_startup.log,vnc_startup.log,wm.log,wm_startup.log}
/home/ubuntu/vnc_startup.sh
/home/ubuntu/servic_vnc_shutdown.sh
#!\bin\bash
source /home/ubuntu/.bash_profile
source /etc/environment
export DISPLAY=:0
xset q;
pkill -9 -f "/home/ubuntu/vnc_startup.sh"
rm -f /home/ubuntu/{no_vnc_startup.log,vnc_startup.log,wm.log,wm_startup.log}
Debugging
Login as user ubuntu.
Run /home/ubuntu/servic_vnc_startup.sh from command line.
If fails, fix it till it is successful.
Then try running /home/ubuntu/servic_vnc_startup.sh as user noboby:
sudo -u nobody "/home/ubuntu/servic_vnc_startup.sh"
User nobody has no shell and no environment context, as is the systemd service /etc/systemd/system/novnc.service.
If user nobody can run /home/ubuntu/servic_vnc_startup.sh then the /etc/systemd/system/novnc.service service unit can do as well.
Do same testing pattern with /home/ubuntu/servic_vnc_shutdown.sh
Lessons to learn:
Simplify service unit as much as possible.
Pull all scripting to a single shell script. Debug single shell script.
Avoid debugging handling service unit once deployed. Instead debug and modify called script.
Use user nobody user, to debug script to run without environment context and without shell.

Bash exit status not working in script

I've written a script that starts, stops and sends status of Apache, with messages dependent on the output of the commands.
I have most of it correct, but my errors are not printing out correctly. In other words, even if I do not have Apache loaded, "stopping" it still shows a successful message.
I need help getting my error messages to print when necessary.
#!/bin/bash
echo -e "\e[1;30mApache Web Server Control Script\e[0m"
echo
echo "Enter the operation number to perform (1-4): "
echo " 1 - Start the httpd server"
echo " 2 - Restart the httpd server"
echo " 3 - Stop the httpd server"
echo " 4 - Check httpd server status"
echo
echo -n "===> "
read NUMBER
EXITSTATUS=$?
echo
if [ $NUMBER -eq "1" ]; then
systemctl start httpd
if [ $EXITSTATUS -eq "0" ]; then
echo -e "\e[1;32mThe return value of the command 'systemctl
start httpd' was 0.\e[0m"
echo -e "\e[1;32mThe Apache web server was successfully
started.\e[0m"
else
echo -e "\e[1;31mThe return value of the command 'systemctl
start httpd' was 5.\e[0m"
echo -e "\e[1;31mThe Apache web server was not successfully
started.\e[0m"
fi
fi
if [ $NUMBER -eq "2" ]; then
systemctl restart httpd
if [ $EXITSTATUS -eq "0" ]; then
echo -e "\e[1;32mThe return value of the command 'systemctl
restart httpd' was 0.\e[0m"
echo -e "\e[1;32mThe Apache web server was successfully
restarted.\e[0m"
else
echo -e "\e[1;31mThe return value of the command 'systemctl
restart httpd' was 5.\e[0m"
echo -e "\e[1;31mThe Apache web server was not successfully
restarted.\e[0m"
fi
fi
if [ $NUMBER -eq "3" ]; then
systemctl stop httpd
if [ $EXITSTATUS -eq "0" ]; then
echo -e "\e[1;32mThe return value of the command 'systemctl
stop httpd' was 0.\e[0m"
echo -e "\e[1;32mThe Apache web server was successfully
stopped\e[0m."
else
echo -e "\e[1;31mThe return value of the command 'systemctl
stop httpd' was 5.\e[0m"
echo -e "\e[0;31mThe Apache web server was successfully
stopped.\e[0m"
fi
fi
if [ $NUMBER -eq "4" ]; then
systemctl status httpd
if [ $EXITSTATUS -eq "0" ]; then
msg=$(systemctl status httpd)
else
echo -e "\e[1;31mThe Apache web server is not currently
running.\e[0m"
echo $(msg)
fi
fi
if [[ $NUMBER != [1-4] ]]; then
echo -e "\e[1;31mPlease select a valid choice: Exiting.\e[0m"
fi
exit 0
The variable EXITSTATUS doesn't contain the exit code of the systemctl calls, but that of the read command. You could rewrite it either as
systemctl start httpd
EXITSTATUS=$?
if [ $EXITSTATUS -eq 0 ]; then
[...]
or more simply as
systemctl start httpd
if [ $? -eq 0 ]; then
[...]
Storing the value of $? in a variable is only necessary if you either want to use it afterwards in another place (e. g. as exit code of your own script), or have to make other calls before branching on the value.
You're not setting your variable $EXITSTATUS after running the commands, so it maintains its original value (the exit status of read NUMBER).
Since you only care about whether the command succeeded or not, better would be to avoid using it entirely and change the conditions to e.g.:
if systemctl restart httpd; then
# it was successful ($? would be 0)
fi

How to see JBOSS has started/stopped from commandline

Is there some linux/jboss command I can use in a script to see if jboss started.
I have to start up a couple in a specified order and one of the jbosses must
be started before the others can be started up.
/T
Refer this link ,With the following command you can try to read the server "Started" attribute
twiddle get "jboss.system:type=Server" Started
Started=true
On Fedora 19, you can install the jboss-as package, which comes with a nice startup script, and you can check the status just like any other daemon: systemctl status jboss-as
Similarly for Fedora 20 and Wildfly: systemctl status wildfly .
Here is a script I used:
#!/bin/bash
CHECK_TIMEOUT=$1;
if [[ $1 =~ ^[0-9]+$ ]]; then
echo "Checking if JBoss is running with timeout of $1 s.";
else
echo "Checking if JBoss is running with default timeout of 60 s.";
CHECK_TIMEOUT=60;
fi
while [[ $CHECK_TIMEOUT -ne 0 ]]
do
sleep 1;
JBOSS_STATE=`~/jboss/bin/jboss-cli.sh 'connect,:read-attribute(name=server-state),q' | grep result`;
if [[ -z $JBOSS_STATE ]]; then
JBOSS_STATE="stopped";
else
JBOSS_STATE=`echo "$JBOSS_STATE" | tr -s \" " " | cut -d ' ' -f 4`;
fi
echo "JBoss is $JBOSS_STATE";
if [[ $JBOSS_STATE == "running" ]]; then
exit 0;
fi
((CHECK_TIMEOUT-=1));
done
exit 1;

check if file exists on remote host with ssh

I would like to check if a certain file exists on the remote host.
I tried this:
$ if [ ssh user#localhost -p 19999 -e /home/user/Dropbox/path/Research_and_Development/Puffer_and_Traps/Repeaters_Network/UBC_LOGS/log1349544129.tar.bz2 ] then echo "okidoke"; else "not okay!" fi
-sh: syntax error: unexpected "else" (expecting "then")
In addition to the answers above, there's the shorthand way to do it:
ssh -q $HOST [[ -f $FILE_PATH ]] && echo "File exists" || echo "File does not exist";
-q is quiet mode, it will suppress warnings and messages.
As #Mat mentioned, one advantage of testing like this is that you can easily swap out the -f for any test operator you like: -nt, -d, -s etc...
Test Operators: http://tldp.org/LDP/abs/html/fto.html
Here is a simple approach:
#!/bin/bash
USE_IP='-o StrictHostKeyChecking=no username#192.168.1.2'
FILE_NAME=/home/user/file.txt
SSH_PASS='sshpass -p password-for-remote-machine'
if $SSH_PASS ssh $USE_IP stat $FILE_NAME \> /dev/null 2\>\&1
then
echo "File exists"
else
echo "File does not exist"
fi
You need to install sshpass on your machine to work it.
Can't get much simpler than this :)
ssh host "test -e /path/to/file"
if [ $? -eq 0 ]; then
# your file exists
fi
As suggested by dimo414, this can be collapsed to:
if ssh host "test -e /path/to/file"; then
# your file exists
fi
one line, proper quoting
ssh remote_host test -f "/path/to/file" && echo found || echo not found
You're missing ;s. The general syntax if you put it all in one line would be:
if thing ; then ... ; else ... ; fi
The thing can be pretty much anything that returns an exit code. The then branch is taken if that thing returns 0, the else branch otherwise.
[ isn't syntax, it's the test program (check out ls /bin/[, it actually exists, man test for the docs – although can also have a built-in version with different/additional features.) which is used to test various common conditions on files and variables. (Note that [[ on the other hand is syntax and is handled by your shell, if it supports it).
For your case, you don't want to use test directly, you want to test something on the remote host. So try something like:
if ssh user#host test -e "$file" ; then ... ; else ... ; fi
Test if a file exists:
HOST="example.com"
FILE="/path/to/file"
if ssh $HOST "test -e $FILE"; then
echo "File exists."
else
echo "File does not exist."
fi
And the opposite, test if a file does not exist:
HOST="example.com"
FILE="/path/to/file"
if ! ssh $HOST "test -e $FILE"; then
echo "File does not exist."
else
echo "File exists."
fi
ssh -q $HOST [[ -f $FILE_PATH ]] && echo "File exists"
The above will run the echo command on the machine you're running the ssh command from. To get the remote server to run the command:
ssh -q $HOST "[[ ! -f $FILE_PATH ]] && touch $FILE_PATH"
Silent check if file exist and perform if not
if ! ssh $USER#$HOST "test -e file.txt" 2> /dev/null; then
echo "File not exist"
fi
You can specify the shell to be used by the remote host locally.
echo 'echo "Bash version: ${BASH_VERSION}"' | ssh -q localhost bash
And be careful to (single-)quote the variables you wish to be expanded by the remote host; otherwise variable expansion will be done by your local shell!
# example for local / remote variable expansion
{
echo "[[ $- == *i* ]] && echo 'Interactive' || echo 'Not interactive'" |
ssh -q localhost bash
echo '[[ $- == *i* ]] && echo "Interactive" || echo "Not interactive"' |
ssh -q localhost bash
}
So, to check if a certain file exists on the remote host you can do the following:
host='localhost' # localhost as test case
file='~/.bash_history'
if `echo 'test -f '"${file}"' && exit 0 || exit 1' | ssh -q "${host}" sh`; then
#if `echo '[[ -f '"${file}"' ]] && exit 0 || exit 1' | ssh -q "${host}" bash`; then
echo exists
else
echo does not exist
fi
I wanted also to check if a remote file exist but with RSH. I have tried the previous solutions but they didn't work with RSH.
Finally, I did I short function which works fine:
function existRemoteFile ()
{
REMOTE=$1
FILE=$2
RESULT=$(rsh -l user $REMOTE "test -e $FILE && echo \"0\" || echo \"1\"")
if [ $RESULT -eq 0 ]
then
return 0
else
return 1
fi
}
On CentOS machine, the oneliner bash that worked for me was:
if ssh <servername> "stat <filename> > /dev/null 2>&1"; then echo "file exists"; else echo "file doesnt exits"; fi
It needed I/O redirection (as the top answer) as well as quotes around the command to be run on remote.
This also works :
if ssh user#ip "[ -s /path/file_name ]" ;then
status=RECEIVED ;
else
status=MISSING ;
fi
#its simple
if [[ "`ssh -q user#hostname ls /dir/filename.abc 2>dev/null`" == "/dir/filename.abc" ]]
then
echo "file exists"
else
echo "file not exists"
fi

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