Shell scripting and test expressions

Question

Hi, I'm trying to test whether a directory path exists when a file is passed to my script. I use dirname to strip and save the path. I want my script to run only if the path exists. This is my attempt below.

FILE=$1 DIRNAME=dirname $FILE

if [ -z $DIRNAME ] ; then echo "Error no file path" exit 1 fi

But this doesn't work. Actual when there is no file path dirname $FILE still returns "." to DIRNAME, i.e. this directory. So how do i distinguish between "." and "/bla/bla/bla".

Thanks.

Answer 1

why not use

 
if [ -a $1] ; then echo "found file"; fi

?

Answer 2

Are you sure dirname is checking the filesystem for existence? What OS are you on? Most dirnames just do string manipulation, I believe. So this:

dirname /one/two/three

Returns /one/two even if /one doesn't exist.

Maybe this is what you're looking for:

FILE=$1
DIRNAME=`dirname "$FILE"`
if [ ! -d "$DIRNAME" ]; then
    echo "$DIRNAME doesn't exist" >&2
    exit 1
fi