Simple Shell Script

frizzant · 07-18-2016, 07:48 AM

Hello lovelies!

I am trying to get a very simple shell script to work. But somehow it never works how i want it to.

So i enter minecraft_starter, the script starts. Now i want to enter minecraft_starter gui, so the elif with the variable gui starts. But it doesn't. I am sure it is pretty simple. Thing is i cant figure it out. And Yes I asked google for the last two hours

.

minecraft_starter:

Code:

#!/bin/bash

if [ "$output" ]
                then java -Xmx3896M -Xms1G -d64 -jar /home/minecraft/minecraft-server/minecraft_server.1.10.2.jar nogui
        elif [ "$gui" ]
                then java -Xmx3896M -Xms1G -d64 -jar /home/minecraft/minecraft-server/minecraft_server.1.10.2.jar
        elif [ "$man" ]
                then echo "output: no nohup or and / gui: no output, and, gui / man: gives manpage similar output / none: silenced."
        else nohup java -Xmx3896M -Xms1G -d64 -jar /home/minecraft/minecraft-server/minecraft_server.1.10.2.jar nogui &
fi

Thanks in advance!

sag47 · 07-18-2016, 10:32 AM

You're passing in arguments, not environment variables. I recommend using a simple case statement with $1 (being the first argument e.g. "gui" in your example). See this init script example.

See also "man test" which will tell you more how to use the bracket for logic.

grail · 07-18-2016, 10:40 AM

sag47 has his wizard hat on .... cause I read the script a few times and had no idea what was going on and was about to ask where all those variables were being set ... nice work

I would also suggest that writing the exact same piece of code bar a single piece of information 3 times could probably be improved.

sag47 · 07-19-2016, 12:17 AM

Alternatively, man test states that:

[ STRING ] is equivalent to [ -n STRING ]

So you could change how you're calling the script. e.g.

Code:

# choose one of the following four ways

gui=1 minecraft_starter

output=1 minecraft_starter

man=1 minecraft_starter

minecraft_starter

So the script can be left as-is if you call it like the above four ways.