Bash: Replace blank spaces with underscore for file(s) in current directory.

blankRename.sh

###
##  Replace blank spaces with underscore for file(s) in current directory
###

function blankRename() {
    ONE=1          # For getting singular/plural right
    number=0       # Keeps track of how many files actually renamed
    FOUND=0        # Successful return value

    # Traverse all files in directory
    for filename in *
    do
        # Check whether filename contains space(s)
        echo "$filename" | grep -q "_"

        if [ $? -eq $FOUND ]
            then
                fname=$filename                      # Strip off path
                n=`echo $fname | sed -e "s/_/-/g"`   # Substitute underscore for blank
                mv "$fname" "$n"                     # Do the actual renaming
                let "number += 1"
        fi
    done

    # For correct grammar
    if [ "$number" -eq "$ONE" ]
        then
            echo "$number file renamed."
    else
        echo "$number files renamed."
    fi

    exit 0
}

great job!