遍历某目录下的所有文件，打印其用途

#!/bin/bash
ARG_COUNT=1
E_NO_ARG=61
E_NOT_DIR=62
if [ $# -ne "$ARG_COUNT" ]; then
        echo "Usage: `basename $0`  directory_name"
        exit $E_NO_ARG
fi

dir=$1

if [ ! -d "$dir" ]; then
        echo "$dir is not a directory"
        exit $E_NOT_DIR
fi


for file in $dir/*
do
        whatis `basename $file`
done

exit 0

示例：

./whatdemo.sh   /usr/bin
./whatdemo.sh "/usr/bin/"&>>usrbin.db