前言

大家在工作的时候可能经常会遇到这样的需求，在类Unix系统的Bash环境下，怎样检查文件是否存在呢？既然有需求，当然就有解决的办法了，Shell中的test命令，可以用来检测文件的类型或者比较数值是否相等，该命令也能用来检查文件是否存在。

可以用如下的命令来进行检查：

test -e filename[ -e filename ] test -f filename[ -f filename ]

下面的命令，则使用Shell的条件表达式，判断/etc/hosts文件是否存在：

[ -f /etc/hosts ] && echo "Found" || echo "Not found"

该组合命令会输出以下内容：

Found

更常见的用法，则是将test命令放置在if..else..fi条件判断的条件表达式，然后在其中写上不同的分支逻辑

#!/bin/bashfile="/etc/hosts"if [ -f "$file" ]then echo "$file found."else echo "$file not found."fi

检测文件属性的相关操作符

如果文件存在，并且具有相应的属性，如下的操作符都会返回true：

-b FILE FILE exists and is block special -c FILE FILE exists and is character special -d FILE FILE exists and is a directory -e FILE FILE exists -f FILE FILE exists and is a regular file -g FILE FILE exists and is set-group-ID -G FILE FILE exists and is owned by the effective group ID -h FILE FILE exists and is a symbolic link (same as -L) -k FILE FILE exists and has its sticky bit set -L FILE FILE exists and is a symbolic link (same as -h) -O FILE FILE exists and is owned by the effective user ID -p FILE FILE exists and is a named pipe -r FILE FILE exists and read permission is granted -s FILE FILE exists and has a size greater than zero -S FILE FILE exists and is a socket -t FD file descriptor FD is opened on a terminal -u FILE FILE exists and its set-user-ID bit is set -w FILE FILE exists and write permission is granted -x FILE FILE exists and execute (or search) permission is granted

以上命令，从man test复制而来。

使用上述符号的方法一模一样：

if [ operator FileName ]then echo "FileName - Found, take some action here"else echo "FileName - Not found, take some action here"fi

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可留言交流。