Games : How do I install Minecraft on Ubuntu 14.04?

I had minecraft on my computer, but there were a lot of problems with it. I looked at another question and followed the advice on it, by deleting my .minecraft folder permanently. Now, how do I install minecraft again? My computer is Ubuntu 14.04. I do not know much about this, so please help me.

Later:

I actually figured out how to reinstall minecraft again. But my original situation was that someone had set a SIGTERM on minecraft, so whenever I downloaded minecraft from the launcher it gets deleted. I thought that if I deleted minecraft and re-installed everything, that would work, but turned out it didn't.

So, how do you get rid of the SIGTERM on minecraft so I can play it again?

Here are the logs from the launcher:

[12:27:27 INFO]: Launching game
[12:27:27 INFO]: Unpacking natives to /home/jing/.minecraft/versions/1.8.3/1.8.3-natives-546279090966
[12:27:27 INFO]: Launching in /home/jing/.minecraft
[12:27:27 INFO]: Half command: /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M -Djava.library.path=/home/jing/.minecraft/versions/1.8.3/1.8.3-natives-546279090966 -cp /home/jing/.minecraft/libraries/oshi-project/oshi-core/1.1/oshi-core-1.1.jar:/home/jing/.minecraft/libraries/net/java/dev/jna/jna/3.4.0/jna-3.4.0.jar:/home/jing/.minecraft/libraries/net/java/dev/jna/platform/3.4.0/platform-3.4.0.jar:/home/jing/.minecraft/libraries/com/ibm/icu/icu4j-core-mojang/51.2/icu4j-core-mojang-51.2.jar:/home/jing/.minecraft/libraries/net/sf/jopt-simple/jopt-simple/4.6/jopt-simple-4.6.jar:/home/jing/.minecraft/libraries/com/paulscode/codecjorbis/20101023/codecjorbis-20101023.jar:/home/jing/.minecraft/libraries/com/paulscode/codecwav/20101023/codecwav-20101023.jar:/home/jing/.minecraft/libraries/com/paulscode/libraryjavasound/20101123/libraryjavasound-20101123.jar:/home/jing/.minecraft/libraries/com/paulscode/librarylwjglopenal/20100824/librarylwjglopenal-20100824.jar:/home/jing/.minecraft/libraries/com/paulscode/soundsystem/20120107/soundsystem-20120107.jar:/home/jing/.minecraft/libraries/io/netty/netty-all/4.0.23.Final/netty-all-4.0.23.Final.jar:/home/jing/.minecraft/libraries/com/google/guava/guava/17.0/guava-17.0.jar:/home/jing/.minecraft/libraries/org/apache/commons/commons-lang3/3.3.2/commons-lang3-3.3.2.jar:/home/jing/.minecraft/libraries/commons-io/commons-io/2.4/commons-io-2.4.jar:/home/jing/.minecraft/libraries/commons-codec/commons-codec/1.9/commons-codec-1.9.jar:/home/jing/.minecraft/libraries/net/java/jinput/jinput/2.0.5/jinput-2.0.5.jar:/home/jing/.minecraft/libraries/net/java/jutils/jutils/1.0.0/jutils-1.0.0.jar:/home/jing/.minecraft/libraries/com/google/code/gson/gson/2.2.4/gson-2.2.4.jar:/home/jing/.minecraft/libraries/com/mojang/authlib/1.5.17/authlib-1.5.17.jar:/home/jing/.minecraft/libraries/com/mojang/realms/1.7.12/realms-1.7.12.jar:/home/jing/.minecraft/libraries/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.jar:/home/jing/.minecraft/libraries/org/apache/httpcomponents/httpclient/4.3.3/httpclient-4.3.3.jar:/home/jing/.minecraft/libraries/commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar:/home/jing/.minecraft/libraries/org/apache/httpcomponents/httpcore/4.3.2/httpcore-4.3.2.jar:/home/jing/.minecraft/libraries/org/apache/logging/log4j/log4j-api/2.0-beta9/log4j-api-2.0-beta9.jar:/home/jing/.minecraft/libraries/org/apache/logging/log4j/log4j-core/2.0-beta9/log4j-core-2.0-beta9.jar:/home/jing/.minecraft/libraries/org/lwjgl/lwjgl/lwjgl/2.9.4-nightly-20150209/lwjgl-2.9.4-nightly-20150209.jar:/home/jing/.minecraft/libraries/org/lwjgl/lwjgl/lwjgl_util/2.9.4-nightly-20150209/lwjgl_util-2.9.4-nightly-20150209.jar:/home/jing/.minecraft/libraries/tv/twitch/twitch/6.5/twitch-6.5.jar:/home/jing/.minecraft/versions/1.8.3/1.8.3.jar net.minecraft.client.main.Main
[12:27:27 INFO]: Looking for orphaned versions to clean up...
[12:27:27 INFO]: Looking for old natives & assets to clean up...
[12:27:30 ERROR]: java.io.IOException: Stream closed
[12:27:30 ERROR]: Game ended with bad state (exit code 143)
[12:27:30 INFO]: Ignoring visibility rule and showing launcher due to a game crash
[12:27:30 INFO]: Deleting /home/jing/.minecraft/versions/1.8.3/1.8.3-natives-546279090966