检查目录外壳中是否存在D.userid

Question

We assume the current directory has a number of directories named D.userid, each of which contains submitted Java files. How to detect if there is D.userid present in a directory? What should be the code. I dont this mine is rite

#!/bin/bash

if [ -d "$D.*" ]
then


else
    echo "no .java file(s) submitted"
    exit    
fi
done

Answer 1

Since you assume there are files, and only want to be informed that there are none, I think this is reasonable:

ls D.* > /dev/null       # try to list the files. we don't need output
return=$?                # save the return value of ls just in case
if [ $return -ne 0 ];    # compare it to 0 (success)
then
    echo "No files."
fi

ls returns 2 if the files are not found, so if you want you can use that directly. Of course, it doesn't check that they are directories, but it's just another way.