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/bash file="/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。
更多使用bash shell检查文件是否存在的方法。