writing a shell script if statement to check for directory

Question

I need to write a script that will recreate my opt folder if it gets deleted when I remove a package from it. Here's a link to my previous post: dpkg remove to stop processes

Now, the issue I'm running into could be better described here: http://lists.debian.org/debian-devel/2006/03/msg00242.html

I was thinking of just adding a postrem script which checks if an opt directory exists, and if not, creates one. My experience with shell scripts is pretty limited though..

score 1 · Answer 1 · answered Aug 27 '12 at 21:37

1

[ -d "$dir" ] || mkdir -p "$dir"

This could be written more verbosely / clearly as:

if ! test -d "$dir"; then
    mkdir -p "$dir"
fi

See help test for more information.

answered Aug 27 '12 at 21:37

We Are All Monica

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Since `mkdir -p $dir` is idempotent, there's no need to test for the directory first. Just `mkdir -p "$dir"` is sufficient. – chepner Aug 27 '12 at 22:04
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You're right. I'm going to leave my answer as is though, because it illustrates a useful construct. – We Are All Monica Aug 27 '12 at 22:07

writing a shell script if statement to check for directory

1 Answers1