Bash shell script: How to set JAVA_HOME environment variable - java

Using openSUSE, I downloaded the Oracle rpms for jdk1.6.0_24 and I want to set the java home environment variable to /usr/java/jdk1.6.0_24 but the /etc/alternatives system is unable to automatically detect this installed JDK. Update-alternatives , or whatever just doesn't find the jdk.
So, I want to detect the JAVA home manually in a BASH script.
If I run this command: sudo find /usr -name 'jdk1.6*' , I get this result:
/usr/java/jdk1.6.0_24
How do pipe that result into a environment variable? I want to do something like
#!/bin/bash
read in JAVA_HOME var from a file
if file doesnt exist
sudo find /usr -name 'jdk1.6*'
prompt user for which jdk is correct
set that choice to a variable
add the JDK to alternatives if it is missing
save variable to a file and dont prompt next time
set the alternatives java choice
fi
echo $JAVA_HOME

something like
#!/bin/bash
function validate_java_home {
if [ -z ${JAVA_HOME} ]
then
# do something if the file doesn't provide ${JAVA_HOME}
else
if [ ! -e ${JAVA_HOME} ]
then
# do something if the file provides a non existent ${JAVA_HOME}
fi
fi
}
if [ ! -e ${YOUR_FILE_NAME_CONTAINING_JAVA_HOME} ]
then
JAVA_HOME_CANDIDATES=$(find /usr -name 'jdk1.6*')
echo "Found the following candidates for JAVA_HOME, reply with the one you want then press return"
echo ""
echo $JAVA_HOME_CANDIDATES
read USER_SUBMITTED_JAVA_HOME
echo "You chose $USER_SUBMITTED_JAVA_HOME"
JAVA_HOME=${USER_SUBMITTED_JAVA_HOME}
else
. ${YOUR_FILE_NAME_CONTAINING_JAVA_HOME}
fi
validate_java_home
export ${JAVA_HOME}
I haven't tested that but hopefully you get the gist (and I'd say using select as per glenn jackman's answer is more concise/friendly, didn't know that existed so I'm glad I read this Q!)

oldIFS="$IFS"
IFS=$'\n'
choices=( $(find /usr/java -type d -maxdepth 1 -print) )
select choice in "${choices[#]}"; do
[[ "$choice" ]] && break
done
IFS="$oldIFS"
export JAVA_HOME="$choice"

Not sitting at a linux terminal, but this should get you going:
...
jdkpath=`sudo find /usr -name 'jdk1.6*'`
export JAVA_HOME=$jdkpath
...
Adjust as needed.

Based on Matt's answer , here is the script I am using:
#!/bin/bash
# JAVA_HOME script for RPM based java installations
# http://www.oracle.com/technetwork/java/javase/install-linux-64-rpm-138254.html
# examine and understand /etc/alternatives before you run this
cd $SITE_HOME
function set_java_home {
if [ -z $JAVA_HOME ]; then
echo "Using default value for JAVA_HOME: /usr/java/default"
JAVA_HOME=/usr/java/default
fi
export -p JAVA_HOME
echo $JAVA_HOME > java.home.config
echo "JAVA_HOME variable set to $JAVA_HOME ."
}
if [ -f java.home.config ]; then
JAVA_HOME=$(<java.home.config)
else
JAVA_HOME_CANDIDATES=$(find /usr -type d -name 'jdk1.6*')
echo "Found the following candidates for JAVA_HOME. Pick one: "
echo "---"
echo $JAVA_HOME_CANDIDATES
echo "---"
read USER_SUBMITTED_JAVA_HOME
echo "You chose $USER_SUBMITTED_JAVA_HOME ."
JAVA_HOME=${USER_SUBMITTED_JAVA_HOME}
fi
# Set the variable
set_java_home

Related

getting the error "TERM environment variable not set" when running a bash script from Java process builder [duplicate]

I have a file.sh with this, when run show : TERM environment variable not set.
smbmount //172.16.44.9/APPS/Interfas/HERRAM/sc5 /mnt/siscont5 -o
iocharset=utf8,username=backup,password=backup2011,r
if [ -f /mnt/siscont5/HER.TXT ]; then
echo "No puedo actualizar ahora"
umount /mnt/siscont5
else
if [ ! -f /home/emni/siscont5/S5.TXT ]; then
echo "Puedo actualizar... "
touch /home/emni/siscont5/HER.TXT
touch /mnt/siscont5/SC5.TXT
mv -f /home/emni/siscont5/CCORPOSD.DBF /mnt/siscont5
mv -f /home/emni/siscont5/CCTRASD.DBF /mnt/siscont5
rm /mnt/siscont5/SC5.TXT
rm /home/emni/siscont5/HER.TXT
echo "La actualizacion ha sido realizada..."
else
echo "No puedo actualizar ahora: Interfaz exportando..."
fi
fi
umount /mnt/siscont5
echo "/mnt/siscont5 desmontada..."
You can see if it's really not set. Run the command set | grep TERM.
If not, you can set it like that:
export TERM=xterm
Using a terminal command i.e. "clear", in a script called from cron (no terminal) will trigger this error message. In your particular script, the smbmount command expects a terminal in which case the work-arounds above are appropriate.
You've answered the question with this statement:
Cron calls this .sh every 2 minutes
Cron does not run in a terminal, so why would you expect one to be set?
The most common reason for getting this error message is because the script attempts to source the user's .profile which does not check that it's running in a terminal before doing something tty related. Workarounds include using a shebang line like:
#!/bin/bash -p
Which causes the sourcing of system-level profile scripts which (one hopes) does not attempt to do anything too silly and will have guards around code that depends on being run from a terminal.
If this is the entirety of the script, then the TERM error is coming from something other than the plain content of the script.
You can replace :
export TERM=xterm
with :
export TERM=linux
It works even in kernel with virgin system.
SOLVED: On Debian 10 by adding "EXPORT TERM=xterm" on the Script executed by CRONTAB (root) but executed as www-data.
$ crontab -e
*/15 * * * * /bin/su - www-data -s /bin/bash -c '/usr/local/bin/todos.sh'
FILE=/usr/local/bin/todos.sh
#!/bin/bash -p
export TERM=xterm && cd /var/www/dokuwiki/data/pages && clear && grep -r -h '|(TO-DO)' > /var/www/todos.txt && chmod 664 /var/www/todos.txt && chown www-data:www-data /var/www/todos.txt
If you are using the Docker PowerShell image set the environment variable for the terminal like this with the -e flag
docker run -i -e "TERM=xterm" mcr.microsoft.com/powershell

How to upgrade Java in tomcat server?

My server is in a Unix environment. And I'm using tomcat server. I'm trying to upgrade the Java version, but tomcat is not starting after the upgrade.
which java still gives the old version.
Below is the script for java pointing to tomcat:
if [ -z "$JAVA_HOME" -a -z "$JRE_HOME" ]; then
some script
fi
else
JAVA_PATH=`which java 2>/dev/null`
if [ "x$JAVA_PATH" != "x" ]; then
JAVA_PATH=`dirname $JAVA_PATH 2>/dev/null`
JRE_HOME=`dirname $JAVA_PATH 2>/dev/null`
fi
if [ "x$JRE_HOME" = "x" ]; then
if [ -x /usr/bin/java ]; then
JRE_HOME=/usr
fi
fi
fi
if [ -z "$JAVA_HOME" -a -z "$JRE_HOME" ]; then
echo "Neither the JAVA_HOME nor the JRE_HOME environment variable is defined"
echo "At least one of these environment variable is needed to run this program"
exit 1
fi
fi
Tomcat uses JAVA_HOME variable to get the path for Java. So the question drills down to how you set JAVA_HOME and where to set it?
You might find JAVA_HOME under less /etc/profile.d/jdk.sh depending on which shell you are using. I am using cshell so its under /etc/profile.d/jdk.csh
If you will check less /etc/profile, this is the file which is loaded when a user logs in. There is a variable called as PATH the value for which might be something like /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin so you can access any executable under these paths.
The line in ponder in /etc/profile is for i in /etc/profile.d/*.sh from where all the variable (in case of bash) will be loaded into the environment. Also, it's important to note, if you are setting values here these variable will be set for all the users not just for one.
You might find this and this answer useful.

Install Java7 on Ubuntu 16.04 through bash script

I have below function java_install written in a bash script to install java on Linux box, to which I pass jdk-1.7.0_80-linux-x64.tgz as JAVA_PACKAGE.
Now what is happening is java gets installed and works fine only within the script. Once I come out of this script, none of the java functionalities work, not even java -version. Could someone please help me on what I might be missing here? Basically, I just want java to be installed permanently on this box once this script is executed.
java_install() {
local JAVA_PACKAGE=$1
local TMPDIR=/tmp/quickstart
local TARGET=/usr/share
if [ -n "$JAVA_PACKAGE" ] && [ -f "$JAVA_PACKAGE" ]; then
rm -rf $TMPDIR
mkdir -p $TMPDIR
cp $JAVA_PACKAGE $TMPDIR
( cd $TMPDIR && tar fxz $JAVA_PACKAGE && rm $JAVA_PACKAGE )
local JAVA_BASENAME=$(ls -1 $TMPDIR)
mkdir -p $TARGET
if [ -d "$TARGET/$JAVA_BASENAME" ]; then
echo "# Java already installed at $TARGET/$JAVA_BASENAME"
log_info "Java already installed at $TARGET/$JAVA_BASENAME"
else
echo "# Java now installed at $TARGET/$JAVA_BASENAME"
log_info "Java now installed at $TARGET/$JAVA_BASENAME"
mv $TMPDIR/$JAVA_BASENAME $TARGET
fi
rm -rf $TMPDIR
# now create a script to export these settings
export JAVA_HOME=$TARGET/$JAVA_BASENAME
export PATH=$JAVA_HOME/bin:$PATH
else
echo "# cannot find java package to install"
log_error "cannot find java package to install"
fi
}
Use update alternatives within your script to make your java installation available:
sudo update-alternatives --install "/usr/bin/java" "java" "path to you java executable" 1
More information on this topic can be found here: How to use the command update-alternatives --config java.
Alternatively you can write the export commands for JAVA HOME and PATH to your .bashrc from within your script (if using bash). This way the modified variables are available in the bash shell.

jboss_init_redhat is not working

I used Redhat and Jboss 4.2.2 GA for application server.
I have a basic problem that when I try to run
./jboss_init_redhat.sh start
is not working.
Basicly I want to run inside jboss_init_redhat.sh file;
/opt/jboss/bin/run.sh -c X -b 0.0.0.0
This line is working but jboss_init_redhat.sh not working.That's our problem.
I checked all permissions but there is not any permission problem.
jboss_init_redhat.sh is below:
#!/bin/sh
#
# $Id: jboss_init_redhat.sh 60992 2007-02-28 11:33:27Z dimitris#jboss.org $
#
# JBoss Control Script
#
# To use this script run it as root - it will switch to the specified user
#
# Here is a little (and extremely primitive) startup/shutdown script
# for RedHat systems. It assumes that JBoss lives in /usr/local/jboss,
# it's run by user 'jboss' and JDK binaries are in /usr/local/jdk/bin.
# All this can be changed in the script itself.
#
# Either modify this script for your requirements or just ensure that
# the following variables are set correctly before calling the script.
#define where jboss is - this is the directory containing directories log, bin, conf etc
JBOSS_HOME=${JBOSS_HOME:-"/opt/jboss"}
#define the user under which jboss will run, or use 'RUNASIS' to run as the current user
JBOSS_USER=${JBOSS_USER:-"jboss"}
#make sure java is in your path
JAVAPTH=${JAVAPTH:-"/usr/local/jdk/bin"}
#configuration to use, usually one of 'minimal', 'default', 'all'
JBOSS_CONF=${JBOSS_CONF:-"ikarus"}
#if JBOSS_HOST specified, use -b to bind jboss services to that address
JBOSS_HOST="0.0.0.0"
JBOSS_BIND_ADDR=${JBOSS_HOST:+"-b $JBOSS_HOST"}
#define the classpath for the shutdown class
JBOSSCP=${JBOSSCP:-"$JBOSS_HOME/bin/shutdown.jar:$JBOSS_HOME/client/jnet.jar"}
#define the script to use to start jboss
JBOSSSH=${JBOSSSH:-"$JBOSS_HOME/bin/run.sh -c $JBOSS_CONF $JBOSS_BIND_ADDR"}
if [ "$JBOSS_USER" = "RUNASIS" ]; then
SUBIT=""
else
SUBIT="su - $JBOSS_USER -c "
fi
if [ -n "$JBOSS_CONSOLE" -a ! -d "$JBOSS_CONSOLE" ]; then
# ensure the file exists
touch $JBOSS_CONSOLE
if [ ! -z "$SUBIT" ]; then
chown $JBOSS_USER $JBOSS_CONSOLE
fi
fi
if [ -n "$JBOSS_CONSOLE" -a ! -f "$JBOSS_CONSOLE" ]; then
echo "WARNING: location for saving console log invalid: $JBOSS_CONSOLE"
echo "WARNING: ignoring it and using /dev/null"
JBOSS_CONSOLE="/dev/null"
fi
#define what will be done with the console log
JBOSS_CONSOLE=${JBOSS_CONSOLE:-"/dev/null"}
JBOSS_CMD_START="cd $JBOSS_HOME/bin; $JBOSSSH"
JBOSS_CMD_STOP=${JBOSS_CMD_STOP:-"java -classpath $JBOSSCP org.jboss.Shutdown --shutdown"}
if [ -z "`echo $PATH | grep $JAVAPTH`" ]; then
export PATH=$PATH:$JAVAPTH
fi
if [ ! -d "$JBOSS_HOME" ]; then
echo JBOSS_HOME does not exist as a valid directory : $JBOSS_HOME
exit 1
fi
echo JBOSS_CMD_START = $JBOSS_CMD_START
case "$1" in
start)
cd $JBOSS_HOME/bin
if [ -z "$SUBIT" ]; then
eval $JBOSS_CMD_START >${JBOSS_CONSOLE} 2>&1 &
else
$SUBIT "$JBOSS_CMD_START >${JBOSS_CONSOLE} 2>&1 &"
fi
;;
stop)
if [ -z "$SUBIT" ]; then
$JBOSS_CMD_STOP
else
$SUBIT "$JBOSS_CMD_STOP"
fi
;;
restart)
$0 stop
$0 start
;;
*)
echo "usage: $0 (start|stop|restart|help)"
esac
If you change JBOSS_USER information to RUNASIS, it should work properly.

Setting Java CLASSPATH doesn't work but -cp does

So, here's the problem I encountered. I wrote a simple .bat file to run weka on some data sets I had but Java recently updated itself and it stopped working. My old code was this:
#ECHO OFF
SET CLASSPATH = "C:\Program Files (x86)\Weka-3-6\weka.jar"
FOR /r %%I IN (*.arff) DO (
ECHO Running %%~nI.arff
java weka.classifiers.meta.FilteredClassifier -t %%~nI.arff -F "weka.filters.unsupervised.attribute.Remove -R 1,3,4,5" -W weka.classifiers.functions.LinearRegression -x 10 >> results.txt
ECHO >> results.txt
)
This worked before and it did the job I asked of it. However, after the java update, I kept getting the error "Could not find or load main class weka.classifiers.meta.FilteredClassifier". I couldn't figure it out because the directory names and class names were exactly correct. So, I changed the code to this:
#ECHO OFF
SET CLASSPATH = "C:\Program Files (x86)\Weka-3-6\weka.jar"
FOR /r %%I IN (*.arff) DO (
ECHO Running %%~nI.arff
java -cp "C:\Program Files (x86)\Weka-3-6\weka.jar" weka.classifiers.meta.FilteredClassifier -t %%~nI.arff -F "weka.filters.unsupervised.attribute.Remove -R 1,3,4,5" -W weka.classifiers.functions.LinearRegression -x 10 >> results.txt
ECHO >> results.txt
)
And it worked again. Can anyone tell me why this happened? The only thing I can think of is that the Java update isn't playing nice with itself somehow. Any insight would be appreciated thanks.
SET WEKA_HOME=c:\Program Files (x86)\Weka-3-6
SET CLASSPATH=%CLASPATH%;%WEKA_HOME%\weka.jar
bash learn.sh

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