Question

code:

path=$PATH:
while [ -n $path ]
do 
ls -ld ${path%%:*}
path=${path#*:}
done

I want to get the each part of path .When run the script ,it can not get out of the while process 。Please tell me why . Is some problem in ‘while [ -n $path ]’ ？

Answer 1

The final cut never results in an empty string. If you have a:b:c, you’ll strip off the a and then the b, but never the c. I.e., this:

${path#*:}

Will always result in a non-empty string for the last piece of the path. Since the -n check looks for an empty string, your loop runs forever.