Detecting failure of a Bash “export” value

Question

In Bash I\'m executing a command and putting the result in a variable like this:

export var=`svn ls`

But if SVN fails for some reason--say it returns a n

Answer 1

I had similar problem, it can be done like this:

rm -f error_marker_file
export var=`svn ls || touch error_marker_file`

[ -f error_marker_file ] && echo "error in executing svn ls"