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displayvar [2008/02/12 13:53] (current)
kleiner created
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 +====== Conditionally setting the DISPLAY variable ======
 +In OS X, if you want to use X11 programs from the Terminal, you have to set the environment variable DISPLAY as follows:
 +  export DISPLAY=:​0.0
 +You can either put this line in your ''​~/​.bashrc''​ or ''​~/​.profile''​ file, such that the variable is always set. This is useful if you have X11 configured to be started automatically with OS X.
  
 +On the other hand, if you only sporadically use ''​X11'',​ the above solution might become a nuisance, especially with programs that try to access an X server, even if they don't actually put any output there (such as Vim). In that case, you can set the variable manually each time you use a program that needs ''​X11''​.
 +
 +In the following we show a third, more elegant solution. It is a short script that detects whether X11 is running, and only then sets the variable.
 +
 +Put the following code in your ''​~/​.bashrc''​ or ''​~/​.profile''​ file:
 +<​code>​
 +PSOUT=`ps auxw | grep '/​Applications/​Utilities/​X11.app/​Contents/​MacOS/​X11'​ | grep -v grep`
 +
 +if [ -n "​$PSOUT"​ ]; then
 +  # X11 is running
 +  export DISPLAY=":​0.0"​
 +fi
 +</​code>​
 +This code checks the list of running processes for an instance of ''​X11''​ by grepping the output of ''​ps'',​ and only sets the variable if the result is a non-zero-length string. ​
displayvar.txt ยท Last modified: 2008/02/12 13:53 by kleiner