Technology Tales

Checking existence of files and directories on UNIX using shell scripting

23^rd April 2007

Having had a UNIX shell script attempt to copy a non-existent file, I decided to take another look for ways to test the existence of a file. For directory existence checking, I was testing for the return code from the cd command, and I suppose that the ls command might help for files. However, I did find a better way:

if [ -f $filename ]
then
    echo "This filename [$filename] exists"
elif [ -d $dirname ]
then
    echo "This dirname [$dirname] exists"
else
    echo "Neither [$dirname] or [$filename] exist"
fi

The -d and -f flags within the evaluation expressions test for the existence of directories and files, respectively. One gotcha is that those spaces within the brackets are important too, but it is a very way of doing what I wanted.

HTML Tidy for Windows

22^nd March 2007

Drupal has modules (Import HTML and its helper Static HTML together make up one option) for importing static (X)HTML pages into its database, and it needs HTML Tidy to work. Since I am playing with the thing on Windows, I went out and snagged the version for that OS. Being either lazy or bloody-minded, I tried an XHTML page with PHP code embedded in it and, needless to say, the thing choked. I must try it with plain XHTML instead.