bash如果条件为循环

Question

Hi I want to create a bash file, where i define multiple files (the number is not set) and the script checks if a md5 hash for each file exist, and creates one if not? I am stuck with the if loop, how can I define a loop with variable length as a if condition?

COMPARE_FILES=("/folder/file1" "/folder2/file2" "file3" ... "/folderN/fileN")

for i in "${COMPARE_FILES[@]}"
do

    base=${i%%.*}                # does not work?
    file=${##*/}                 # works as expected

    if [ ! -f $COMPARE_DIR/compare/$base.md5 ]; then

        rsync $COMPARE_LOC/"$i" $COMPARE_DIR/compare/       #works as expected
        md5sum $COMPARE_LOC/$file > $COMPARE_DIR/$base.md5
        rm $COMPARE_DIR/compare/$file                        #does not work

    fi
done

I am not able to extract the filename and the base name from the array in the loop, can someone help me perhaps?

Answer 1

To get the basename from a filepath, use basename :

$ i="/file/path/filename.ext"
$ base=$(basename $i)
$ echo $base
filename.ext

Then you can get the filename without extension as you were doing:

$ fnam=${base%.*}
$ echo $fnam
filename

Or the extension:

$ extn=${base#*.}
$ echo $extn
ext