#!/bin/bash
if [ $# -lt 1 ];then
 echo "Usage:$0 + filepath"
 exit
fi          #判断用户是否输入了参数
match=$1  #将要查的文件赋值给变量match
found=0    #定义一个初始变量作为发生条件，当文件找到时对此变量重新赋值
for file in /etc/*  #对目录进行遍历
do
 if [ $file == $match ];then   #判断文件是否匹配
   echo "the file $match was found!"
   found=1               #当文件匹配时，对初始变量重新赋值
   break                  #文件找到后跳出循环
 fi
done
[ $found -ne 1 ] && echo "the file $match is not in /etc directory."   #做最终的判断，文件未找到时found仍然是0，判断条件成立，输出文件未找到；当文件找到时，found被赋值为1，条件不成立，不做输出。

#!/bin/bash
if [ $# -lt 2 ];then
 echo "Usage:$0 + filepath + directorypath"
 exit
fi
match=$1
found=0
for file in ${2}*    #在位置参数2，用户给定的目录中(一层目录)遍历所有文件
do
 if [ $file == $match ];then
   echo "the file $match was found!"
   found=1
   break
 fi
done
[ $found -ne 1 ] && echo "the file $match is not in /etc directory."